JP6245533B2 - Inspection apparatus and imaging device manufacturing method - Google Patents

Inspection apparatus and imaging device manufacturing method Download PDF

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JP6245533B2
JP6245533B2 JP2016077039A JP2016077039A JP6245533B2 JP 6245533 B2 JP6245533 B2 JP 6245533B2 JP 2016077039 A JP2016077039 A JP 2016077039A JP 2016077039 A JP2016077039 A JP 2016077039A JP 6245533 B2 JP6245533 B2 JP 6245533B2
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向井　香織
香織 向井
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本発明は、被照射物を照明する照明装置、照明装置を備える検査装置、および検査装置を使用する撮像素子の製造方法に関する。   The present invention relates to an illumination device that illuminates an object to be irradiated, an inspection device including the illumination device, and a method for manufacturing an image sensor using the inspection device.

デジタルカメラ等に使用される固体撮像素子、例えばＣＣＤ型又はＣＭＯＳ型の撮像素子は、半導体ウエハ（以下、単にウエハという。）の表面にＣＶＤ(chemical vapor deposition)工程及びフォトリソグラフィー工程等により半導体集積回路を積層して形成される。この際、一般に１枚のウエハ表面に多数の固体撮像素子がマトリクス状に整列した状態で形成され、かつ各固体撮像素子はウエハ上に整列した状態で性能検査が行われる。この検査に合格した素子がウエハから切り離されてデジタルカメラ等に使用される。   Solid-state image sensors used in digital cameras and the like, for example, CCD-type or CMOS-type image sensors, are integrated on the surface of a semiconductor wafer (hereinafter simply referred to as a wafer) by a CVD (chemical vapor deposition) process, a photolithography process, or the like. It is formed by stacking circuits. At this time, in general, a large number of solid-state image sensors are formed in a matrix on the surface of one wafer, and performance inspection is performed with each solid-state image sensor aligned on the wafer. Elements that pass this inspection are separated from the wafer and used in a digital camera or the like.

従来、ウエハ上に整列形成された状態の複数の固体撮像素子の検査を行うために、ウエハ表面の検査対象素子を照度均一性の高い照明光で照明する照明装置と、ウエハを移動するプローバと、検査対象素子の電気出力を取り込んで性能を検査するテスタとを有する検査装置が使用されている。従来の照明装置は、照明光としてフィラメントを有するランプよりなる光源から発生する非偏光で広帯域の光（白色光）を使用していた（例えば、特許文献１参照）。   Conventionally, in order to inspect a plurality of solid-state image sensors arranged in alignment on a wafer, an illumination device that illuminates an inspection target element on the wafer surface with illumination light with high illuminance uniformity, and a prober that moves the wafer An inspection apparatus having a tester that takes in an electrical output of an element to be inspected and inspects performance is used. A conventional lighting device uses non-polarized broadband light (white light) generated from a light source made of a lamp having a filament as illumination light (see, for example, Patent Document 1).

その他、繰り返しパターンが形成されたウエハの表面に直線偏光の平行光（照明光）を入射させて、パターンから反射した光を検出することでパターンの欠陥を検査する装置が用いられる。この検査装置では例えば、光源からの直線偏光の発散光束を平行光に変換してウエハ表面へ導くために凹面反射鏡が使用される。このとき、凹面反射鏡での反射により照明光の偏光面（直線偏光の偏光方位角）の回転が生じるため、この回転を抑制するために例えば光源からの発散光束中（非平行光束中）に平行平面板が配置される（例えば、特許文献２参照）。   In addition, there is used an apparatus for inspecting a pattern defect by making linearly polarized parallel light (illumination light) incident on the surface of a wafer on which a repeated pattern is formed and detecting light reflected from the pattern. In this inspection apparatus, for example, a concave reflecting mirror is used to convert a linearly polarized divergent light beam from a light source into parallel light and guide it to the wafer surface. At this time, rotation of the polarization plane of illumination light (polarization azimuth angle of linearly polarized light) occurs due to reflection by the concave reflecting mirror. Therefore, in order to suppress this rotation, for example, in a divergent light beam from a light source (in a non-parallel light beam) A plane parallel plate is disposed (see, for example, Patent Document 2).

特開２００６−２２２３２５号公報JP 2006-222325 A 米国特許第７３０７７２５号明細書US Pat. No. 7,307,725

固体撮像素子を検査するために照明装置から照射される照明光の条件として、まずランプから射出された直後のように非偏光な光（偏光度がほぼ０％の光）であることが好ましい。しかしながら、光源から非偏光な光が射出されたとしても、照明装置の途中の光路にある例えば光路折り曲げ用のミラーのような光学部材によって偏光度が変化して、検査対象素子に照射される照明光の偏光度が大きくなると（偏光度が許容範囲を超える）と、検出器等の偏光依存性のために検査精度が低下するおそれがある。   As a condition of illumination light emitted from the illumination device in order to inspect the solid-state imaging device, it is preferable that the light is first non-polarized light (light having a polarization degree of approximately 0%) just after being emitted from the lamp. However, even when non-polarized light is emitted from the light source, the degree of polarization is changed by an optical member such as a mirror for bending the optical path in the optical path in the middle of the illuminating device, and illumination is applied to the inspection target element When the degree of polarization of light becomes large (the degree of polarization exceeds an allowable range), the inspection accuracy may decrease due to polarization dependency of a detector or the like.

また、例えば固体撮像素子の偏光特性を検査するような場合には、例えばその照明光を回転角が調整可能な直線偏光板に通すことによって、その照明光を任意の方向の直線偏光に設定できることが好ましい。しかしながら、その直線偏光板に通す前の照明光が非偏光な光でないと、その直線偏光板を通過した後の照明光の偏光方向（偏光方位角）によって光量が変動して、検査精度が低下するおそれがある。   For example, when inspecting the polarization characteristics of a solid-state imaging device, the illumination light can be set to linearly polarized light in an arbitrary direction by passing the illumination light through a linear polarizing plate whose rotation angle can be adjusted, for example. Is preferred. However, if the illumination light before passing through the linear polarizing plate is not non-polarized light, the amount of light varies depending on the polarization direction (polarization azimuth angle) of the illumination light after passing through the linear polarizing plate, resulting in a decrease in inspection accuracy. There is a risk.

本発明の態様は、このような事情に鑑み、非偏光な光（偏光度がほぼ０％の光）で検査対象素子を照明することを目的とする。   In view of such circumstances, an aspect of the present invention aims to illuminate an inspection target element with non-polarized light (light having a polarization degree of approximately 0%).

本発明によれば、被検査物を検査する検査装置において、光源から発生した光が入射する第１光学部材と、その光に対する透過性を有し、その被検査物へ非偏光な光が入射するようにその光の偏光度を変化させる第２光学部材と、を有する照明装置と、その照明装置からの光で照明されたその被検査物からの出力を検出し、該検出の結果に基づいてその被検査物を検査する検査部と、を備え、その第２光学部材は、その光源の中心から射出された光がその照明装置の光軸に実質的に平行になる位置に配置される検査装置が提供される。
また、その検査装置において、一例として、その第２光学部材は、板状光学部材を含み、その照明装置の光軸に垂直な面に対して傾斜して配置され、他の例として、その照明装置は、その光源からの光が入射するオプティカルインテグレータと、そのオプティカルインテグレータにおける光の射出面からの光をその被検査物へ略テレセントリックにケーラー照明するコンデンサレンズと、を更に有する。 According to the present invention, in an inspection apparatus for inspecting an object to be inspected, a first optical member on which light generated from a light source is incident, and light having transparency to the light, and non-polarized light is incident on the object to be inspected. A second optical member that changes the degree of polarization of the light so as to detect the output from the object illuminated by the light from the illumination device, and based on the detection result And the second optical member is arranged at a position where the light emitted from the center of the light source is substantially parallel to the optical axis of the illuminating device. An inspection device is provided.
Moreover, in the inspection apparatus, as an example, the second optical member includes a plate-like optical member, and is disposed to be inclined with respect to a plane perpendicular to the optical axis of the illumination apparatus. The apparatus further includes an optical integrator on which light from the light source is incident, and a condenser lens that performs Koeler illumination of light from the light exit surface of the optical integrator to the inspection object in a substantially telecentric manner .

また、本明細書には以下の発明も記載されている。
本発明の第１の態様によれば、被照射物を照明する照明装置において、非偏光な光を発生する光源部と、その光源部から発生された光の少なくとも一部の光路を折り曲げる第１光学部材と、その光に対する透過性を有し、その第１光学部材により増加するその光の偏光度を低減させる第２光学部材と、を備え、その第２光学部材は、その光源部の中心から射出された光が該照明装置の光軸に実質的に平行になる位置に配置される照明装置が提供される。
第２の態様によれば、被照射物を照明する照明装置において、非偏光な光を発生する光源部と、その光源部からの光の少なくとも一部の光路を折り曲げる第１光学部材と、その光源部からの光が入射するオプティカルインテグレータと、その光に対する透過性を有し、その第１光学部材により増加するその光の偏光度を低減させる第２光学部材と、を備え、その第２光学部材は、そのオプティカルインテグレータにおける光の射出面の中心から射出された光が該照明装置の光軸に実質的に平行になる位置に配置される照明装置が提供される。 The present invention also describes the following invention.
According to the first aspect of the present invention, in the illumination device that illuminates the irradiated object, the light source unit that generates non-polarized light and the first light path that bends at least a part of the light path generated from the light source unit. An optical member, and a second optical member that is transparent to the light and reduces the degree of polarization of the light that is increased by the first optical member, the second optical member being the center of the light source unit There is provided an illuminating device in which light emitted from the illuminating device is disposed at a position substantially parallel to the optical axis of the illuminating device.
According to the second aspect, in the illumination device that illuminates the irradiated object, the light source unit that generates non-polarized light, the first optical member that bends the optical path of at least part of the light from the light source unit, and the An optical integrator that receives light from the light source unit, and a second optical member that has transparency to the light and that reduces the degree of polarization of the light that is increased by the first optical member. The member is provided with an illuminating device in which light emitted from the center of the light emitting surface of the optical integrator is arranged at a position substantially parallel to the optical axis of the illuminating device.

第３の態様によれば、被照射物を照明する照明装置において、光を発生する光源部と、その光源部から発生されたその光の少なくとも一部の光路を折り曲げる第１光学部材と、その光に対する透過性を有し、その被照射物へ非偏光な光が入射するようにその光の偏光度を変化させる第２光学部材と、を備え、その第２光学部材は、その光源部の中心から射出された光が該照明装置の光軸に実質的に平行になる位置に配置される照明装置が提供される。   According to the third aspect, in the illumination device that illuminates the irradiated object, the light source unit that generates light, the first optical member that bends at least a part of the optical path of the light generated from the light source unit, and the A second optical member having transparency to light and changing a degree of polarization of the light so that non-polarized light is incident on the irradiated object, the second optical member of the light source unit A lighting device is provided in which light emitted from the center is arranged at a position substantially parallel to the optical axis of the lighting device.

第４の態様によれば、被照射物を照明する照明装置において、光を発生する光源部と、その光源部から発生された光の少なくとも一部の光路を折り曲げる第１光学部材と、その光源部からの光が入射するオプティカルインテグレータと、その光に対する透過性を有し、その被照射物へ非偏光な光が入射するように光の偏光度を変化させる第２光学部材と、を備え、その第２光学部材は、そのオプティカルインテグレータにおける光の射出面の中心から射出された光が該照明装置の光軸に実質的に平行になる位置に配置される照明装置が提供される。   According to the fourth aspect, in the illumination device that illuminates the irradiated object, the light source unit that generates light, the first optical member that bends at least a part of the optical path of the light generated from the light source unit, and the light source An optical integrator on which light from the unit is incident, and a second optical member that has transparency to the light and changes the degree of polarization of the light so that non-polarized light is incident on the irradiated object, The second optical member is provided with an illuminating device in which light emitted from the center of the light exit surface of the optical integrator is disposed at a position substantially parallel to the optical axis of the illuminating device.

第５の態様によれば、被照射物を照明する照明装置において、非偏光な光を発生する光源部と、その光源部からの光が入射するオプティカルインテグレータと、その光源部からの光の一部を折り曲げる第１光学部材と、そのオプティカルインテグレータにおける光の射出面からの光をその被照射物へ略テレセントリックにケーラー照明するコンデンサレンズと、そのコンデンサレンズとその被照射物との間に配置され、その光に対する透過性を有し、その第１光学部材により増加する光の偏光度を低減させる平行平面板と、を備える照明装置が提供される。   According to the fifth aspect, in the illumination device that illuminates the irradiated object, the light source unit that generates non-polarized light, the optical integrator on which the light from the light source unit is incident, and the light from the light source unit A first optical member that bends the light source, a condenser lens that provides Koeler illumination of light from the light exit surface of the optical integrator to the irradiated object in a substantially telecentric manner, and the condenser lens and the irradiated object. There is provided an illuminating device including a plane-parallel plate that has transparency to the light and reduces the degree of polarization of light that is increased by the first optical member.

また、第６の態様によれば、第１〜第５の態様の照明装置と、その照明装置からの光で照明される被検査物が載置されるステージと、その照明装置からの光で照明されたその被検査物からの出力を検出し、該検出の結果に基づいてその被検査物を検査する検査部と、を備える検査装置が提供される。
また、第７の態様によれば、本発明の態様の検査装置で撮像素子の検査を行う工程を含む撮像素子の製造方法が提供される。 Moreover, according to the 6th aspect, with the illumination apparatus of the 1st-5th aspect, the stage by which the to-be-inspected object illuminated with the light from the illumination apparatus is mounted, and the light from the illumination apparatus An inspection apparatus is provided that includes an inspection unit that detects an output from the illuminated inspection object and inspects the inspection object based on a result of the detection.
Moreover, according to the 7th aspect, the manufacturing method of an image pick-up element including the process of test | inspecting an image pick-up element with the test | inspection apparatus of the aspect of this invention is provided.

本発明の態様によれば、非偏光な光（偏光度がほぼ０％の光）で被検査物を照明することができる。   According to the aspect of the present invention, the object to be inspected can be illuminated with non-polarized light (light having a polarization degree of approximately 0%).

第１の実施形態に係る検査装置を示す図である。It is a figure showing the inspection device concerning a 1st embodiment. （ａ）はアルミニウムコートのミラーの反射率の波長依存性（入射角４５°）を示す図、（ｂ）はその反射率の入射角依存性（波長５５０ｎｍ）を示す図、（ｃ）はそのミラーの偏光度の波長依存性（入射角４５°）を示す図、（ｄ）はその偏光度の入射角依存性（波長５５０ｎｍ）を示す図である。(A) is a diagram showing the wavelength dependence (incident angle 45 °) of the reflectance of the aluminum-coated mirror, (b) is a diagram showing the incident angle dependence (wavelength 550 nm) of the reflectance, and (c) is the diagram The figure which shows the wavelength dependence (incident angle 45 degrees) of the polarization degree of a mirror, (d) is a figure which shows the incident angle dependence (wavelength 550nm) of the polarization degree. （ａ）は１つの反射面あたりのエネルギー反射率の入射角依存性（基板材料がＢＫ７）を示す図、（ｂ）は１枚の基板(2面)あたりのエネルギー透過率の入射角依存性（基板材料がＢＫ７）を示す図、（ｃ）は平行平面板の透過の偏光度の入射角依存性（基板材料がＢＫ７）を示す図、（ｄ）は平行平面板（基板材料がＢＫ７）による偏光度の波長依存性（入射角２８°）を示す図である。(A) is a graph showing the incident angle dependency of the energy reflectance per one reflecting surface (substrate material is BK7), and (b) is the incident angle dependency of the energy transmittance per one substrate (two surfaces). (C) is a diagram showing the incident angle dependence of the degree of polarization of transmission of a plane parallel plate (substrate material is BK7), (d) is a plane parallel plate (substrate material is BK7). It is a figure which shows the wavelength dependence (incidence angle of 28 degrees) of the degree of polarization by. ウエハの上方に直線偏光板を配置した状態の検査装置を示す図である。It is a figure which shows the inspection apparatus of the state which has arrange | positioned the linear polarizing plate above a wafer. 平行平面板の透過の偏光度の入射角依存性（基板材料がＳＦ６）を示す図である。It is a figure which shows the incident angle dependence (substrate material is SF6) of the polarization degree of the transmission of a parallel plane plate. 第２の実施形態に係る検査装置を示す図である。It is a figure which shows the inspection apparatus which concerns on 2nd Embodiment. （ａ）は図６の検査装置の照明領域を示す平面図、（ｂ）は他の照明領域を示す平面図である。(A) is a top view which shows the illumination area of the inspection apparatus of FIG. 6, (b) is a top view which shows another illumination area. 第３の実施形態に係る照明装置を示す斜視図である。It is a perspective view which shows the illuminating device which concerns on 3rd Embodiment. 撮像素子の製造工程の一例を示すフローチャートである。It is a flowchart which shows an example of the manufacturing process of an image pick-up element.

［第１の実施形態］
本発明の第１の実施形態につき図１〜図５を参照して説明する。図１は、本実施形態に係る検査装置１００を示す。検査装置１００は、一例としてシリコン等からなるウエハ（半導体ウエハ）５０の表面に整列形成された状態の複数のＣＣＤ型又はＣＭＯＳ型等の固体撮像素子５８（図７（ａ）参照）の性能を検査するものである。検査装置１００は、被検査物であるウエハ５０表面の被照射面１６を均一な照度分布の照明光ＩＬで照明する照明装置８０と、ウエハ５０を移動するプローバ９０と、ウエハ５０表面の検査対象の固体撮像素子（検査対象素子）の電気出力を取り込んでその性能を検査するテスタ５６と、装置全体の動作を統括的に制御するコンピュータよりなる主制御装置５３と、照明装置８０を構成する光学部材等を支持するフレーム機構（不図示）とを有する。以下、ウエハ５０が移動する平面内で図１の紙面に平行な方向にＸ軸を、図１の紙面に垂直な方向にＹ軸を取り、その平面に垂直な方向にＺ軸を取り、Ｚ軸に平行な軸の回りの回転方向をθｚ方向として説明する。 [First Embodiment]
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows an inspection apparatus 100 according to the present embodiment. As an example, the inspection apparatus 100 has the performance of a plurality of CCD-type or CMOS-type solid-state imaging elements 58 (see FIG. 7A) in a state of being aligned on the surface of a wafer (semiconductor wafer) 50 made of silicon or the like. It is to be inspected. The inspection apparatus 100 includes an illumination device 80 that illuminates the irradiated surface 16 of the surface of the wafer 50, which is an object to be inspected, with illumination light IL having a uniform illuminance distribution, a prober 90 that moves the wafer 50, and an inspection target on the surface of the wafer 50. The tester 56 that takes in the electrical output of the solid-state image pickup device (device to be inspected) and inspects its performance, the main controller 53 comprising a computer that controls the overall operation of the entire device, and the optics that constitutes the illumination device 80 A frame mechanism (not shown) for supporting members and the like. Hereinafter, in the plane in which the wafer 50 moves, the X axis is taken in the direction parallel to the paper surface of FIG. 1, the Y axis is taken in the direction perpendicular to the paper surface in FIG. 1, and the Z axis is taken in the direction perpendicular to the plane. The rotation direction around an axis parallel to the axis will be described as the θz direction.

まず、プローバ９０は、ウエハ５０が載置されるステージ５１、ステージ５１をＸ方向、Ｙ方向、及びθｚ方向に駆動するステージ駆動装置５２、並びにウエハ５０表面の検査対象素子の出力端子に接触可能な複数のプローブピン５５を有する。テスタ５６は、プローブピン５５を介して得られる検査対象素子（照明装置８０で照明されている）の電気信号（出力）からその検査対象素子の性能を検査する。主制御装置５３は、不図示のアライメント系の検出結果に基づいてステージ駆動装置５２を介してステージ５１（ウエハ５０）を移動して、検査対象素子を照明装置８０の被照射面１６の照明領域内に移動する。   First, the prober 90 can contact the stage 51 on which the wafer 50 is placed, the stage driving device 52 that drives the stage 51 in the X direction, the Y direction, and the θz direction, and the output terminal of the inspection target element on the surface of the wafer 50. A plurality of probe pins 55. The tester 56 inspects the performance of the inspection target element from the electrical signal (output) of the inspection target element (illuminated by the illumination device 80) obtained through the probe pin 55. The main control device 53 moves the stage 51 (wafer 50) via the stage driving device 52 based on the detection result of the alignment system (not shown), and the inspection target element is illuminated on the illuminated surface 16 of the illumination device 80. Move in.

また、照明装置８０は、ほぼ４００〜７００ｎｍ程度の広帯域の波長範囲を含み非偏光な照明光ＩＬを射出する光源１を有する。光源１から射出された照明光ＩＬは、撮像素子が受光する光の３原色である赤色光（中心波長６００ｎｍ）、緑色光（中心波長５５５ｎｍ）、及び青色光（中心波長４５０ｎｍ）を含む白色光である。光源１としては、一例と
してフィラメントを有するハロゲンランプが使用されている。なお、光源１としては、一般的な白熱電球又はキセノンランプ等も使用可能である。 Moreover, the illuminating device 80 includes the light source 1 that emits non-polarized illumination light IL that includes a wide wavelength range of approximately 400 to 700 nm. The illumination light IL emitted from the light source 1 is white light including red light (center wavelength: 600 nm), green light (center wavelength: 555 nm), and blue light (center wavelength: 450 nm), which are the three primary colors received by the image sensor. It is. For example, a halogen lamp having a filament is used as the light source 1. As the light source 1, a general incandescent lamp or a xenon lamp can be used.

さらに、照明装置８０は、光源１から被照射面１６に向かって順に配列された複数の光学部材、すなわち、コレクタレンズ２、フィルタ群３、リレー光学系４、リレー光学系４からほぼ＋Ｘ方向に射出された光束をほぼ−Ｚ方向に９０°折り曲げる平面ミラーよりなる折り返しミラー５、及び照明むらを減少させるためのフライアイレンズ６（オプティカルインテグレータ）を有する。また、照明装置８０は、フライアイレンズ６からの光束を集光して被照射面１６をテレセントリック照明するコンデンサレンズ７、照明装置８０の光学系の光軸ＡＸに垂直な平面１５に対して斜めに配置された光透過性の平行平面板よりなる偏光補正板８、及び照明光路に対して挿脱可能に、かつθｚ方向に回転可能に支持された直線偏光板（偏光子）９を有する。フィルタ群３は、熱線吸収フィルタ３Ａ、交換可能なカラーフィルタ３Ｂ、光量を制御するために交換可能なＮＤフィルタ３Ｃ、及びバンドパスフィルタ（不図示）などを有する。   Further, the illumination device 80 is substantially in the + X direction from a plurality of optical members arranged in order from the light source 1 toward the irradiated surface 16, that is, the collector lens 2, the filter group 3, the relay optical system 4, and the relay optical system 4. It has a folding mirror 5 made of a plane mirror that bends the emitted light beam approximately 90 ° in the −Z direction, and a fly-eye lens 6 (optical integrator) for reducing illumination unevenness. Further, the illumination device 80 condenses the light flux from the fly-eye lens 6 and telecentricly illuminates the irradiated surface 16, and is inclined with respect to the plane 15 perpendicular to the optical axis AX of the optical system of the illumination device 80. And a linearly polarizing plate (polarizer) 9 supported so as to be able to be inserted into and removed from the illumination light path and to be rotatable in the θz direction. The filter group 3 includes a heat ray absorption filter 3A, a replaceable color filter 3B, a replaceable ND filter 3C for controlling the amount of light, a band pass filter (not shown), and the like.

折り返しミラー５は、一例としてガラス板の反射面にアルミニウム等の金属膜を形成したものである。折り返しミラー５の反射面５ａは照明装置８０の光軸ＡＸに対して、Ｙ軸に平行な軸の回りに４５°傾斜している。フライアイレンズ６は、一例として断面形状が正方形の複数のレンズエレメントを密着して束ねたものである。このとき、フライアイレンズ６の入射面と被照射面１６とはコンデンサレンズ７によって共役であるため、被照射面１６の照明領域の形状も正方形である。偏光補正板８の材料（硝材）は、屈折率が例えば１．５以上に高い材料が望ましい。   As an example, the folding mirror 5 is formed by forming a metal film such as aluminum on the reflecting surface of a glass plate. The reflecting surface 5a of the folding mirror 5 is inclined by 45 ° around an axis parallel to the Y axis with respect to the optical axis AX of the illumination device 80. As an example, the fly-eye lens 6 is formed by closely bonding a plurality of lens elements having a square cross-sectional shape. At this time, since the entrance surface of the fly-eye lens 6 and the irradiated surface 16 are conjugated by the condenser lens 7, the shape of the illumination area of the irradiated surface 16 is also square. The material (glass material) of the polarization correction plate 8 is desirably a material having a refractive index as high as 1.5 or more.

また、照明装置８０は、偏光補正板８の平面１５に対する傾き角αを調整する角度調整機構１０、及び直線偏光板９を必要に応じて照明光路に設置し、かつその照明光路で直線偏光板９をθｚ方向に回転する挿脱回転機構２０を有する。角度調整機構１０は、偏光補正板８の−Ｘ方向の端部を回転可能に支持する支持部１１、偏光補正板８の＋Ｘ方向の端部を支持する支持部１２、円弧状のガイド部１４、及びガイド部１４に沿って歯車機構を介して支持部１２を移動させる駆動部１３を有する。駆動部１３はマニュアルでもよいが、駆動モータで駆動してもよい。また、さらに偏光補正板８及び角度調整機構１０を一体的にθｚ方向に回転する回転機構（不図示）を設けることが望ましい。この場合、角度調整機構１０および不図示の回転機構により、照明装置８０の光軸Ａｘに対する任意の方位において、偏光補正板８の傾き角αを可変させることができる。なお、角度調整機構１０および回転機構（不図示）に限定されることなく、照明装置８０の光軸Ａｘに対する任意の方位において偏光補正板８の偏光補正板８の傾き角αを任意に設定できる機構であれば、例えば偏光補正板８を３点でキネマティック支持するなど、既存の機構を適用することができる。挿脱回転機構２０は、直線偏光板９を支持する支持枠２１、支持枠２１を内側で回転可能に支持する軸受け２２、軸受け２２の外枠を回転して軸受け２２内の直線偏光板９を照明光路に設置し、かつ照明光路から退避させる第１駆動モータ２３、及び軸受け２２内で支持枠２１（直線偏光板９）をθｚ方向に回転させる第２駆動モータ２４を有する。なお、角度調整機構１０及び挿脱回転機構２０の構成は上記の構成に限られることはなく、周知の技術を適用してもよい。   In addition, the illumination device 80 is provided with an angle adjustment mechanism 10 that adjusts an inclination angle α of the polarization correction plate 8 with respect to the plane 15 and a linear polarization plate 9 in the illumination optical path as necessary, and the linear polarization plate in the illumination optical path. It has an insertion / removal rotation mechanism 20 that rotates 9 in the θz direction. The angle adjustment mechanism 10 includes a support portion 11 that rotatably supports an end portion of the polarization correction plate 8 in the −X direction, a support portion 12 that supports an end portion of the polarization correction plate 8 in the + X direction, and an arcuate guide portion 14. And the drive part 13 which moves the support part 12 via a gear mechanism along the guide part 14 is provided. The drive unit 13 may be a manual, but may be driven by a drive motor. Further, it is desirable to provide a rotation mechanism (not shown) that integrally rotates the polarization correction plate 8 and the angle adjustment mechanism 10 in the θz direction. In this case, the tilt angle α of the polarization correction plate 8 can be varied in an arbitrary direction with respect to the optical axis Ax of the illumination device 80 by the angle adjustment mechanism 10 and a rotation mechanism (not shown). The tilt angle α of the polarization correction plate 8 of the polarization correction plate 8 can be arbitrarily set in an arbitrary direction with respect to the optical axis Ax of the illumination device 80 without being limited to the angle adjustment mechanism 10 and the rotation mechanism (not shown). If it is a mechanism, for example, an existing mechanism such as kinematic support of the polarization correction plate 8 at three points can be applied. The insertion / removal rotation mechanism 20 rotates the support frame 21 that supports the linear polarizing plate 9, the bearing 22 that rotatably supports the support frame 21 on the inside, and the outer frame of the bearing 22 to rotate the linear polarizing plate 9 in the bearing 22. A first drive motor 23 installed in the illumination optical path and retracted from the illumination optical path, and a second drive motor 24 that rotates the support frame 21 (linearly polarizing plate 9) in the bearing 22 in the θz direction. Note that the configurations of the angle adjustment mechanism 10 and the insertion / removal rotation mechanism 20 are not limited to the above-described configurations, and a known technique may be applied.

照明装置８０において、光源１から射出された光束（照明光ＩＬ）は、コレクタレンズ２によりほぼ＋Ｘ方向に向かう略平行光束に変換され（コリメートされ）、フィルタ群３に入射する。フィルタ群３を配置する位置は、光束径が小さくなるコレクタレンズ２の後ろ側焦点付近やリレー光学系４の中間位置（光源像ができる位置）付近が望ましい。また、フィルタ群３のフィルタ３Ａ〜３Ｃ等は互いに異なる位置に配置してもよい。フィルタ３Ａ〜３Ｃ等は、多重反射の影響を軽減するために傾けて配置する場合もある。フィルタ群３を通過した光束は、リレー光学系４により、フライアイレンズ６に入射するのに適切なサイズと開口数（ＮＡ）を持つ光束に変換され、折り返しミラー５を介してフライアイレンズ６に入射する。   In the illuminating device 80, the light beam (illumination light IL) emitted from the light source 1 is converted (collimated) into a substantially parallel light beam substantially in the + X direction by the collector lens 2 and enters the filter group 3. The position where the filter group 3 is disposed is preferably near the back focal point of the collector lens 2 where the beam diameter is small or near the intermediate position (position where a light source image can be generated) of the relay optical system 4. Further, the filters 3A to 3C of the filter group 3 may be arranged at different positions. The filters 3A to 3C and the like may be arranged at an angle in order to reduce the influence of multiple reflection. The light beam that has passed through the filter group 3 is converted by the relay optical system 4 into a light beam having a size and a numerical aperture (NA) appropriate for entering the fly-eye lens 6, and the fly-eye lens 6 is passed through the folding mirror 5. Is incident on.

本実施形態では、照明装置８０ひいては検査装置１００を小型化するために、リレー光学系４とフライアイレンズ６との間に折り返しミラー５が配置されている。折り返しミラー５は、光源１の中心又はフライアイレンズ６の射出面の中心からの光が光軸ＡＸと略平行になる位置に設置するのが望ましい。この位置であれば、被照射面１６の各位置に集光される光束は、折り返しミラー５への入射角分布が互いにほぼ等しい光束になっているため、折り返しミラー５が傾斜していることによる光量のむら（傾斜むら）が生じにくい。仮に折り返しミラー５をリレー光学系４の中間位置に配置すると、折り返しミラー５への光の入射角分布が、被照射面１６の集光位置に依存して異なる。この場合、一般にミラーの反射率は入射角依存性があるので、照明光の光量むら（傾斜むら）が生じる。   In the present embodiment, the folding mirror 5 is disposed between the relay optical system 4 and the fly-eye lens 6 in order to reduce the size of the illumination device 80 and thus the inspection device 100. The folding mirror 5 is desirably installed at a position where light from the center of the light source 1 or the center of the exit surface of the fly-eye lens 6 is substantially parallel to the optical axis AX. If it is this position, since the light flux condensed on each position of the irradiated surface 16 is a light flux whose incident angle distribution to the folding mirror 5 is substantially equal to each other, the folding mirror 5 is inclined. Unevenness of light intensity (inclination unevenness) is unlikely to occur. If the folding mirror 5 is arranged at an intermediate position of the relay optical system 4, the incident angle distribution of the light to the folding mirror 5 differs depending on the condensing position of the irradiated surface 16. In this case, since the reflectance of the mirror generally depends on the incident angle, unevenness in the amount of illumination light (inclination unevenness) occurs.

そして、フライアイレンズ６の射出面を２次光源とするケーラー照明になるように、フライアイレンズ６から射出される光束でコンデンサレンズ７によって被照射面１６を照明する。この際にテレセントリック照明になるように、概ねコンデンサレンズ７の前側焦点位置がフライアイレンズ６の射出面（瞳面又は二次光源が形成される面）に設定されている。   Then, the irradiated surface 16 is illuminated by the condenser lens 7 with a light beam emitted from the fly-eye lens 6 so as to be Koehler illumination using the exit surface of the fly-eye lens 6 as a secondary light source. At this time, the front focal position of the condenser lens 7 is generally set to the exit surface of the fly-eye lens 6 (the surface on which the pupil surface or the secondary light source is formed) so as to achieve telecentric illumination.

次に、本実施形態における偏光補正板８の作用につき説明する。本実施形態に係る検査装置１００によるウエハ５０表面の検査対象素子の検査に際して、第１の検査方法としては、例えば検査対象素子の偏光依存性の影響を解消するために、検査対象素子に非偏光な光束を照射する。この第１の検査方法では、直線偏光板９は照明光路の外部に退避している。また、光源１としては非偏光な照明光ＩＬを射出する光源が使用されている。ところが、照明装置８０の小型化のために使用されている折り返しミラー５は、ｓ偏光とｐ偏光の反射率が異なるため、折り返しミラー５で反射された後の光束の偏光度は変化し（偏光度は上がり）、例えば数％程度の偏光度を持つことがある。より詳しくは、折り返しミラー５で反射された後の光束に直線偏光成分が生じるため、偏光度が上がることがある。   Next, the operation of the polarization correction plate 8 in this embodiment will be described. When inspecting the inspection target element on the surface of the wafer 50 by the inspection apparatus 100 according to the present embodiment, as a first inspection method, for example, in order to eliminate the influence of the polarization dependence of the inspection target element, the non-polarized light is applied to the inspection target element. Irradiate a light flux. In this first inspection method, the linearly polarizing plate 9 is retracted outside the illumination optical path. As the light source 1, a light source that emits non-polarized illumination light IL is used. However, since the reflection mirror 5 used to reduce the size of the illumination device 80 has different reflectances for s-polarized light and p-polarized light, the degree of polarization of the light beam reflected by the folding mirror 5 changes (polarized light). For example, the degree of polarization may be about several percent. More specifically, since a linearly polarized light component is generated in the light beam reflected by the folding mirror 5, the degree of polarization may increase.

なお、被照射面１６に入射する光束に関して、Ｘ方向の偏光成分（折り返しミラー５に関するｐ偏光）とＹ方向の偏光成分（折り返しミラー５に関するｓ偏光）との強度差をＳ１、Ｘ方向に対して４５°傾斜した偏光成分と１３５°傾斜した偏光成分との強度差をＳ２、右円偏光と左円偏光との強度差をＳ３、全光束の強度をＳＴとすると、偏光度は次のように定義される。   It should be noted that the intensity difference between the polarized light component in the X direction (p-polarized light with respect to the folding mirror 5) and the polarized light component in the Y direction (s-polarized light with respect to the folded mirror 5) with respect to S1 and the X direction. S2 is the intensity difference between the polarization component tilted by 45 ° and the polarization component tilted by 135 °, S3 is the difference in intensity between right circular polarization and left circular polarization, and ST is the intensity of the total luminous flux. Defined in

偏光度＝｛（Ｓ１2＋Ｓ２2＋Ｓ３2）1/2／ＳＴ｝×１００（％） …（１）
以下、偏光度がほぼ０％と見做せる光(偏光度が１％以下程度の光)を非偏光な光と表す。
また、白色光で使用されるミラー用コーティングは一般にはアルミニウムコートである。そこで、一例として折り返しミラー５も反射面にアルミニウムコートが施されたミラー（アルミミラー）であるとすると、アルミミラーは４５°入射で概ね９０％程度の反射率を持つ。さらに、アルミミラーでは、ｓ偏光とｐ偏光に対する反射率特性に、図２（ａ）（入射角４５°の場合）及び図２（ｂ）（波長５５０ｎｍの場合）に示すように５％程度の差がある。 Polarization degree = {(S1 2 + S2 2 + S3 2 ) 1/2 / ST} × 100 (%) (1)
Hereinafter, light that can be regarded as having a degree of polarization of approximately 0% (light having a degree of polarization of about 1% or less) is referred to as non-polarized light.
The mirror coating used for white light is generally an aluminum coat. Therefore, as an example, if the folding mirror 5 is also a mirror (aluminum mirror) having an aluminum coating on the reflecting surface, the aluminum mirror has a reflectivity of approximately 90% at 45 ° incidence. Further, in the aluminum mirror, the reflectance characteristics for s-polarized light and p-polarized light are about 5% as shown in FIG. 2A (when the incident angle is 45 °) and FIG. 2B (when the wavelength is 550 nm). There is a difference.

本実施形態のように固体撮像素子の検査用の検査装置１００では、広い波長範囲に対応している方が望ましいが、広い波長範囲に対応するミラーであると偏光が生じやすい。なお、検査用の光がレーザ光のような単波長の光でよい場合には、単波長のミラー用コーティングは、ｓ偏光及びｐ偏光ともにほぼ１００％の非常に高い反射率を得ることも可能であるため、偏光はほとんど生じない。   In the inspection apparatus 100 for inspecting a solid-state image sensor as in the present embodiment, it is desirable to support a wide wavelength range. However, if the mirror is compatible with a wide wavelength range, polarized light tends to be generated. When the inspection light may be a single-wavelength light such as a laser beam, the single-wavelength mirror coating can obtain a very high reflectance of almost 100% for both s-polarized light and p-polarized light. Therefore, almost no polarization occurs.

非偏光な光束が折り返しミラー５（ここではアルミミラー）に入射したときの反射光の偏光度の波長依存性及び入射角依存性をそれぞれ図２（ｃ）（入射角４５°の場合）及び図２（ｄ）（波長５５０ｎｍの場合）に示す。アルミミラーからの反射光の偏光度は、波長依存性は小さいが（図２（ｃ）参照）、入射角依存性は大きい（図２（ｄ）参照）。折り返しミラー５に対する光束の入射角は４５°の近傍であるため、折り返しミラー５からの反射光の偏光度はほぼ３％になっている。その他にも、照明光路中に光軸に垂直な面に対して斜めに配置されるビームスプリッター等の光学部材などがある場合にも、その光学部材を通過した後の光束の偏光度が変化する。   The wavelength dependence and incidence angle dependence of the degree of polarization of reflected light when a non-polarized light beam enters the folding mirror 5 (here, an aluminum mirror) are shown in FIG. 2 (d) (when wavelength is 550 nm). The degree of polarization of the reflected light from the aluminum mirror has a small wavelength dependency (see FIG. 2C), but has a large incident angle dependency (see FIG. 2D). Since the incident angle of the light beam with respect to the folding mirror 5 is in the vicinity of 45 °, the degree of polarization of the reflected light from the folding mirror 5 is approximately 3%. In addition, when there is an optical member such as a beam splitter disposed obliquely with respect to a plane perpendicular to the optical axis in the illumination optical path, the degree of polarization of the light beam after passing through the optical member changes. .

本実施形態では、折り返しミラー５で反射された光束に生じた偏光度の変化（偏光度の増加分）を低減（より具体的には、折り返しミラー５で反射された光束に生じた直線偏光の成分を低減）するために、コンデンサレンズ７と被照射面１６との間に傾斜した平行平面板よりなる偏光補正板８を配置している。平行平面板を斜めに配置するとｓ偏光とｐ偏光とで透過率が異なるため、折り返しミラー５で生じたｓ偏光とｐ偏光との強度差を減少させて、偏光度を低下させることができる。一例として、偏光補正板８の材料としてはＢＫ７（ｄ線屈折率＝１．５１６８）を使用する。ＢＫ７の屈折率は１．５に対してあまり高くはないが、大きな平行平面板の入手性が良い。   In the present embodiment, a change in the degree of polarization (an increase in the degree of polarization) generated in the light beam reflected by the folding mirror 5 is reduced (more specifically, linearly polarized light generated in the light beam reflected by the folding mirror 5). In order to reduce the component, a polarization correction plate 8 made of a parallel plane plate inclined is disposed between the condenser lens 7 and the irradiated surface 16. When the plane-parallel plate is disposed obliquely, the transmittance differs between the s-polarized light and the p-polarized light. Therefore, the intensity difference between the s-polarized light and the p-polarized light generated by the folding mirror 5 can be reduced, and the degree of polarization can be lowered. As an example, BK7 (d-line refractive index = 1.5168) is used as the material of the polarization correction plate 8. Although the refractive index of BK7 is not so high with respect to 1.5, the availability of a large plane-parallel plate is good.

ここで、平行平面板によるｐ偏光及びｓ偏光の光束の入射角とフレネル反射率（エネルギー反射率）Ｒｐ，Ｒｓとの関係は次の通りである。
Ｒｐ＝tan2（θ1−θ2）／tan2（θ1＋θ2） …（２）
Ｒｓ＝sin2（θ1−θ2）／sin2（θ1＋θ2） …（３）
sinθ1＝ｎsinθ2 …（４）
なお、θ1は空気中での入射角、θ2は平行平面板中での屈折角、ｎは平行平面板の屈折率である。平行平面板（偏光補正板８）の材料がＢＫ７の場合の、入射角とｐ偏光及びｓ偏光のエネルギー反射率との関係（１反射面あたり）を図３（ａ）に、入射角とｐ偏光及びｓ偏光のエネルギー透過率との関係（平行平面板１枚あたり）を図３（ｂ）に、非偏光光が入射したときの入射角と透過光の偏光度との関係を図３（ｃ）に、非偏光光が入射したときの波長と透過光の偏光度との関係（入射角２８°の場合）を図３（ｄ）に示す。光学硝子の屈折率の波長依存性は小さいので、図３（ｄ）に示すように透過光の偏光度の波長依存性も小さい。なお、図１の偏光補正板８の表面８ａ（光が入射する面）に対する光軸に平行な光束の入射角は、角度調整機構１０によって調整される平面１５に対する傾き角αと同じである。 Here, the relationship between the incident angles of the p-polarized light and the s-polarized light flux by the plane-parallel plate and the Fresnel reflectivity (energy reflectivity) Rp, Rs is as follows.
Rp = tan 2 (θ 1 −θ 2 ) / tan 2 (θ 1 + θ 2 ) (2)
Rs = sin 2 (θ 1 −θ 2 ) / sin 2 (θ 1 + θ 2 ) (3)
sinθ 1 = nsinθ 2 (4)
Here, θ 1 is an incident angle in air, θ 2 is a refraction angle in a plane parallel plate, and n is a refractive index of the plane parallel plate. When the material of the plane-parallel plate (polarization correction plate 8) is BK7, the relationship between the incident angle and the energy reflectance of p-polarized light and s-polarized light (per reflecting surface) is shown in FIG. FIG. 3B shows the relationship between the polarized light and s-polarized energy transmittance (per parallel plane plate), and FIG. 3B shows the relationship between the incident angle when non-polarized light is incident and the degree of polarization of the transmitted light. FIG. 3D shows the relationship between the wavelength when non-polarized light is incident and the degree of polarization of the transmitted light (when the incident angle is 28 °). Since the wavelength dependence of the refractive index of the optical glass is small, as shown in FIG. 3D, the wavelength dependence of the degree of polarization of transmitted light is also small. The incident angle of the light beam parallel to the optical axis with respect to the surface 8a (the surface on which light is incident) of the polarization correction plate 8 of FIG. 1 is the same as the inclination angle α with respect to the plane 15 adjusted by the angle adjusting mechanism 10.

本実施形態において、折り返しミラー５ではｓ偏光の方がｐ偏光より反射率が高いので、図１において紙面に平行な面（ＸＺ面）を光の入射面とすると、折り返しミラー５の反射光は、図１の紙面に垂直な方向（Ｙ軸方向）の直線偏光成分が生じる（すなわち、折り返しミラー５の反射光の偏光度が上がる）。なお、折り返しミラー５では位相差と反射率の差で偏光成分が生じるが、非偏光な光源１から射出される光の位相はランダムであり、位相差による影響は小さい。   In the present embodiment, since the s-polarized light in the folding mirror 5 has a higher reflectance than the p-polarized light, if the plane parallel to the paper surface (XZ plane) in FIG. A linearly polarized light component in a direction perpendicular to the paper surface of FIG. 1 (Y-axis direction) is generated (that is, the degree of polarization of the reflected light of the folding mirror 5 is increased). In the folding mirror 5, a polarization component is generated due to the difference between the phase difference and the reflectance, but the phase of the light emitted from the non-polarized light source 1 is random, and the influence of the phase difference is small.

これに対して、偏光補正板８（平行平面板）ではｐ偏光の方がｓ偏光より透過率が高いので、図１の配置（偏光補正板８が平面１５に対してＹ軸に平行な軸の回りに傾斜している配置）では、偏光補正板８に非偏光な光束が入射すると、図１の紙面に平行な方向（Ｘ軸方向）の直線偏光成分が生じる。
したがって、折り返しミラー５と偏光補正板８との組み合わせでは、それらの直線偏光成分（Ｙ軸方向の直線偏光成分とＸ軸方向の直線偏光成分）が相殺するため、偏光補正板８の傾き角α（入射角）を調整することにより、偏光補正板８を透過して被照射面１６に向かう光束の偏光度を小さくできる。偏光補正板８の硝材がＢＫ７の場合、傾き角αが２８°程度で透過光の偏光度が３％程度となり、４５°で傾斜している折り返しミラー５（アルミミラー）で生じる偏光度がほぼ相殺される。 On the other hand, in the polarization correction plate 8 (parallel plane plate), the p-polarized light has higher transmittance than the s-polarized light. Therefore, the arrangement of FIG. 1 (the polarization correction plate 8 is parallel to the Y axis with respect to the plane 15). 1), when a non-polarized light beam enters the polarization correction plate 8, a linearly polarized light component in a direction parallel to the paper surface of FIG. 1 (X-axis direction) is generated.
Therefore, in the combination of the folding mirror 5 and the polarization correction plate 8, their linear polarization components (linear polarization component in the Y-axis direction and linear polarization component in the X-axis direction) cancel each other. By adjusting the (incident angle), the degree of polarization of the light beam that passes through the polarization correction plate 8 and travels toward the irradiated surface 16 can be reduced. When the glass material of the polarization correction plate 8 is BK7, the polarization angle of the transmitted light is about 3% when the inclination angle α is about 28 °, and the degree of polarization generated by the folding mirror 5 (aluminum mirror) inclined at 45 ° is almost equal. Offset.

図１のように、光源１の中心からの照明光ＩＬが光軸ＡＸに略平行になっている位置に折り返しミラー５を配置すると、照明位置が異なっていても折り返しミラー５への入射角は同じような分布になる。そのため、折り返しミラー５で生じる偏光度は照明位置が異なっていてもほぼ３％程度になる。また、照明光ＩＬの波長が異なっていても、その偏光度の波長依存性は小さい。さらに、偏光補正板８は、テレセントリック照明を行うコンデンサレンズ７と被照射面１６との間で、フライアイレンズ６の射出面の中心からの光束が光軸ＡＸにほぼ平行になっている位置にある。従って、偏光補正板８に入射する光束は、照明位置が異なっていても入射角は同じような分布になる。また、偏光補正板８（平行平面板）による偏光度の波長依存性は小さい。従って、被照射面１６の照明領域全面にわたって、波長範囲を広くして、かつ折り返しミラー５における反射で増加した光の偏光度（反射で生じた直線偏光成分）を低減することができる。   As shown in FIG. 1, when the folding mirror 5 is arranged at a position where the illumination light IL from the center of the light source 1 is substantially parallel to the optical axis AX, the incident angle to the folding mirror 5 is different even if the illumination position is different. Similar distribution. Therefore, the degree of polarization generated in the folding mirror 5 is about 3% even if the illumination position is different. Further, even if the wavelength of the illumination light IL is different, the wavelength dependence of the degree of polarization is small. Further, the polarization correction plate 8 is positioned between the condenser lens 7 that performs telecentric illumination and the irradiated surface 16 so that the light beam from the center of the exit surface of the fly-eye lens 6 is substantially parallel to the optical axis AX. is there. Therefore, the light beams incident on the polarization correction plate 8 have the same distribution of incident angles even if the illumination positions are different. Further, the wavelength dependence of the degree of polarization by the polarization correction plate 8 (parallel flat plate) is small. Accordingly, it is possible to widen the wavelength range over the entire illumination area of the irradiated surface 16 and reduce the degree of polarization of light (linearly polarized light component generated by reflection) increased by reflection at the folding mirror 5.

なお、実用的には、ステージ５１上に入射光の偏光度を計測できるポラリメータ５７を設置し、ポラリメータ５７を被照射面１６内に移動した状態で、照明装置８０から被照射面１６に照明光ＩＬを照射してもよい。そして、ポラリメータ５７で計測される偏光度が例えば１％（又はこれよりも小さい許容値）より小さくなるように、又はその偏光度が最小になるように角度調整機構１０で偏光補正板８の傾き角αを調整することで、被照射面１６を非偏光な照明光で照明できる。   Practically, a polarimeter 57 that can measure the degree of polarization of incident light is installed on the stage 51, and the illumination light is applied from the illumination device 80 to the irradiated surface 16 in a state where the polarimeter 57 is moved into the irradiated surface 16. IL may be irradiated. Then, the angle adjustment mechanism 10 tilts the polarization correction plate 8 so that the degree of polarization measured by the polarimeter 57 is smaller than, for example, 1% (or an allowable value smaller than this), or the degree of polarization is minimized. By adjusting the angle α, the irradiated surface 16 can be illuminated with non-polarized illumination light.

次に、本実施形態における第２の検査方法としては、例えば検査対象素子の偏光特性を計測するために、プローバ９０のステージ５１に載置されているウエハ５０を直線偏光した光束で照明する。この検査方法では、上記のように偏光補正板８の傾き角αを、偏光補正板８を透過する光束が非偏光になるように設定した上で、図４に示すように、挿脱回転機構２０によって直線偏光板（偏光子）９を照明光路に設置する。この状態で、被照射面１６を照明光で照明し、テスタ５６によって検査対象素子の性能を検査する。   Next, as a second inspection method in the present embodiment, the wafer 50 placed on the stage 51 of the prober 90 is illuminated with a linearly polarized light beam, for example, in order to measure the polarization characteristics of the inspection target element. In this inspection method, as described above, the inclination angle α of the polarization correction plate 8 is set so that the light beam transmitted through the polarization correction plate 8 becomes non-polarized light, and as shown in FIG. A linear polarizing plate (polarizer) 9 is installed by 20 in the illumination optical path. In this state, the irradiated surface 16 is illuminated with illumination light, and the tester 56 inspects the performance of the inspection target element.

さらに、必要に応じて、検査対象素子に照射される照明光の直線偏光の方向（偏光方位角）を種々の方向に設定して偏光特性を検査するために、挿脱回転機構２０によって直線偏光板９をθｚ方向に回転する。この際に、本実施形態では、直線偏光板９に入射する照明光は非偏光であるため、直線偏光板９をθｚ方向に回転しても、直線偏光板９を透過する直線偏光の光束の光量が変化しない。従って、直線偏光板９の回転角を任意の角度に設定しても、光量が変化しないため、検査対象素子の偏光特性を高精度に検査できる。   Furthermore, in order to inspect the polarization characteristics by setting the direction (polarization azimuth angle) of the linearly polarized light of the illumination light applied to the inspection target element to various directions as necessary, the insertion / removal rotation mechanism 20 performs linearly polarized light. The plate 9 is rotated in the θz direction. At this time, in this embodiment, since the illumination light incident on the linearly polarizing plate 9 is non-polarized light, even if the linearly polarizing plate 9 is rotated in the θz direction, the linearly polarized light beam that passes through the linearly polarizing plate 9 is transmitted. The amount of light does not change. Therefore, even if the rotation angle of the linear polarizing plate 9 is set to an arbitrary angle, the amount of light does not change, so that the polarization characteristics of the element to be inspected can be inspected with high accuracy.

本実施形態の効果等は以下の通りである。
本実施形態に係る検査装置１００は、被照射面１６にあるウエハ５０表面の固体撮像素子（被照射物）を照明する照明装置８０を備えている。そして、照明装置８０は、非偏光で広帯域の光を発生する光源１と、光源１から発生された光の光路を折り曲げる折り返しミラー５と、光源１からの光が入射するフライアイレンズ６と、その光に対する透過性を有し、折り返しミラー５により増加するその光の偏光度を低減させる偏光補正板８と、を備え、偏光補正板８は、フライアイレンズ６における光の射出面の中心から射出された光が照明装置８０の光軸ＡＸに実質的に平行になる位置に配置されている。 The effects and the like of this embodiment are as follows.
The inspection apparatus 100 according to the present embodiment includes an illuminating device 80 that illuminates a solid-state imaging device (irradiated object) on the surface of the wafer 50 on the irradiated surface 16. The illumination device 80 includes a non-polarized light source 1 that generates broadband light, a folding mirror 5 that bends an optical path of light generated from the light source 1, a fly-eye lens 6 on which light from the light source 1 is incident, A polarization correction plate 8 that has transparency to the light and reduces the degree of polarization of the light that is increased by the folding mirror 5, and the polarization correction plate 8 extends from the center of the light exit surface of the fly-eye lens 6. The emitted light is disposed at a position that is substantially parallel to the optical axis AX of the illumination device 80.

照明装置８０によれば、光源１から発生された広帯域（白色）で非偏光な光束の偏光度が折り返しミラー５によって変化（増加）しても、偏光補正板８によってその変化(偏光
度の増加分)が低減される。従って、光源１から発生される非偏光な光束の偏光度の変化
（偏光度の増加）が抑制でき、検査対象の固体撮像素子（被照射面１６）を広帯域でかつ非偏光な光束で照明できる。 According to the illumination device 80, even if the polarization degree of the broadband (white) non-polarized light beam generated from the light source 1 is changed (increased) by the folding mirror 5, the change (increase of the polarization degree) is caused by the polarization correction plate 8. Min) is reduced. Accordingly, a change in the degree of polarization of the non-polarized light beam generated from the light source 1 (increase in the degree of polarization) can be suppressed, and the solid-state imaging device (irradiated surface 16) to be inspected can be illuminated with a wide band and a non-polarized light beam. .

なお、偏光補正板８は、光が入射する表面８ａを有しており、偏光補正板８は、その表面８ａと直交する軸に対して、その光の主光線（照明装置８０に設けられた不図示の開口絞りの中心を通る光線。ここではフライアイレンズ６の射出面（瞳面）の中心を通る斜光線）が交差して表面８ａに入射するように配置されていてもよい。これによって、偏光補正板８に入射する光には常にｓ偏光及びｐ偏光の成分が含まれるため、折り返しミラー５で反射した光の偏光度の変化を補正することが可能となる。これより、照明装置８０で構成される光学系が偏心光学系であったとしても、折り返しミラー５で反射した光の偏光度の変化を偏光補正板８で補正することが可能となる。   The polarization correction plate 8 has a surface 8a on which light is incident, and the polarization correction plate 8 has a principal ray of the light (provided in the illumination device 80) with respect to an axis orthogonal to the surface 8a. A light beam that passes through the center of an aperture stop (not shown) (here, an oblique light beam that passes through the center of the exit surface (pupil surface) of the fly-eye lens 6) may intersect and enter the surface 8a. As a result, since the light incident on the polarization correction plate 8 always contains s-polarized light and p-polarized light components, it is possible to correct the change in the degree of polarization of the light reflected by the folding mirror 5. Thus, even if the optical system configured by the illumination device 80 is a decentered optical system, it is possible to correct the change in the degree of polarization of the light reflected by the folding mirror 5 by the polarization correction plate 8.

また、照明装置８０は照度分布を均一化するためのフライアイレンズ６を備え、偏光補正板８は、フライアイレンズ６の射出面（二次光源）の中心からの光束が光軸ＡＸに略平行になる位置に配置されている。従って、照明位置に依らずに、被照射面１６の各位置に集光する光束の偏光補正板８への入射角分布がほぼ均一であるため、被照射面１６上の照明位置の相違による偏光度のばらつきを小さくできる。   Further, the illumination device 80 includes a fly-eye lens 6 for making the illuminance distribution uniform, and the polarization correction plate 8 has a light flux from the center of the exit surface (secondary light source) of the fly-eye lens 6 approximately on the optical axis AX. They are arranged in parallel positions. Accordingly, since the incident angle distribution on the polarization correction plate 8 of the light beam condensed at each position on the illuminated surface 16 is almost uniform regardless of the illumination position, the polarization due to the difference in illumination position on the illuminated surface 16 is achieved. The variation in degree can be reduced.

また、偏光補正板８は平行平面板であり、製造が容易である。ただし、偏光補正板８としては、例えば表面８aと裏面との間に或る程度の角度がある楔型プリズムのような楔形
状の光学部材（板状光学部材）を使用することも可能である。この場合、例えば、楔形状の光学部材に入射する面（表面）と平面１５との成す角を傾き角αとして光軸ＡＸに対して楔形状の光学部材を傾斜させる。この場合、αが零でないことを光軸に対して傾斜していると考える。
また、本実施形態ではリレー光学系４を備えているが、リレー光学系４は省略可能である。また、光源１は必ずしも広帯域でなくともよく、例えば特定波長の光に対する撮像素子の特性を検査する場合には、光源１として単色で非偏光な光を発生する光源を使用してもよい。この場合、折り返しミラーであれば、反射率が１００％に近いレーザーミラーを使用すれば、直線偏光成分はほとんど生じないが、ビームスプリッター等では直線偏光成分を生じないようにするのは難しい。 The polarization correction plate 8 is a plane parallel plate and is easy to manufacture. However, as the polarization correction plate 8, it is also possible to use a wedge-shaped optical member (plate-shaped optical member) such as a wedge-shaped prism having a certain angle between the front surface 8a and the back surface. . In this case, for example, the wedge-shaped optical member is inclined with respect to the optical axis AX with the angle formed by the plane (surface) incident on the wedge-shaped optical member and the plane 15 as the inclination angle α. In this case, it is considered that α is not zero and is inclined with respect to the optical axis.
Moreover, although the relay optical system 4 is provided in this embodiment, the relay optical system 4 can be omitted. Further, the light source 1 does not necessarily have a wide band. For example, when inspecting characteristics of an image sensor with respect to light of a specific wavelength, a light source that generates monochromatic and non-polarized light may be used as the light source 1. In this case, if the mirror is a folding mirror, a linearly polarized light component is hardly generated if a laser mirror having a reflectance close to 100% is used, but it is difficult to prevent a linearly polarized light component from being generated by a beam splitter or the like.

また、検査装置１００は、照明装置８０と、照明装置８０からの光で照明される被検査物（ウエハ５０表面の固体撮像素子）が載置されるステージ５１と、照明装置５０からの光で照明されたその被検査物からの出力を検出し、この検出の結果に基づいてその被検査物を検査するテスタ５６（検査部）と、を備えている。検査装置１００によれば、照明装置８０から非偏光な光で被検査物（固体撮像素子）を照明できるため、その検査を高精度に行うことができる。   In addition, the inspection apparatus 100 uses the illumination device 80, the stage 51 on which the inspection object illuminated by the light from the illumination device 80 (solid-state image sensor on the surface of the wafer 50) is placed, and the illumination device 50. And a tester 56 (inspection unit) that detects an output from the illuminated inspection object and inspects the inspection object based on a result of the detection. According to the inspection apparatus 100, since the inspection object (solid-state imaging device) can be illuminated with non-polarized light from the illumination device 80, the inspection can be performed with high accuracy.

また、照明装置８０は偏光補正板８の傾き角αを調整する角度調整機構１０を有するため、例えばカラーフィルタ３Ｂの交換時等に、偏光補正板８を透過する光束の偏光度が最小になるようにその傾き角αを調整することもできる。ただし、偏光度の波長依存性は小さいため、偏光補正板８の傾き角αは、一度調整した後は固定することも可能である。このように傾き角αを固定しておく場合には、角度調整機構１０を設けることなく、偏光補正板８を調整機構のない支持部材で支持してもよい。   In addition, since the illumination device 80 includes the angle adjustment mechanism 10 that adjusts the inclination angle α of the polarization correction plate 8, for example, when the color filter 3B is replaced, the degree of polarization of the light beam transmitted through the polarization correction plate 8 is minimized. Thus, the inclination angle α can be adjusted. However, since the wavelength dependence of the degree of polarization is small, the tilt angle α of the polarization correction plate 8 can be fixed after being adjusted once. When the tilt angle α is fixed in this way, the polarization correction plate 8 may be supported by a support member having no adjustment mechanism without providing the angle adjustment mechanism 10.

また、本実施形態では偏光補正板８の硝材はＢＫ７であるため入手が容易である。実際には、偏光補正板８（平行平面板）の硝材としては、屈折率が高い方が傾き角αを小さくできるため、配置が容易になるという利点がある。
図５は、偏光補正板８の硝材としてＳＦ６（ｄ線屈折率＝１．８０５１８０）を使用した場合の、透過光の偏光度の入射角依存性を示す。図５より、ＳＦ６（重フリントガラス）を用いた場合には、偏光度を３％とするための入射角（傾き角α）はほぼ２１°となり、ＢＫ７（クラウンガラス）を用いた場合の２８°よりも小さくなるため、偏光補正板８の配置が容易である。 Further, in the present embodiment, the glass material of the polarization correction plate 8 is BK7, so that it is easy to obtain. Actually, the glass material of the polarization correction plate 8 (parallel flat plate) has an advantage that the higher the refractive index, the smaller the inclination angle α, and the easier the arrangement.
FIG. 5 shows the incident angle dependence of the degree of polarization of transmitted light when SF6 (d-line refractive index = 1.805180) is used as the glass material of the polarization correction plate 8. From FIG. 5, when SF6 (heavy flint glass) is used, the incident angle (tilt angle α) for setting the degree of polarization to 3% is approximately 21 °, which is 28 when BK7 (crown glass) is used. Since it becomes smaller than °, the arrangement of the polarization correction plate 8 is easy.

また、偏光補正板８を配置する位置としては、偏光補正板８に表面８aに対する光の入
射角度分布をほぼ等しくして被照射面１６における光量むら（傾斜むら）を抑制するため、光源１（又は二次光源）の中心からの光束が光軸ＡＸに略平行になる位置（又は被照射面１６の各位置に集光される光束において、それぞれの光束の偏光補正板８への入射角分布が互いに等しくなるような位置）が望ましい。そのため、偏光補正板８は、本実施形態のようにコンデンサレンズ７と被照射面１６との間の他に、例えばフィルタ群３とリレー光学系４との間の位置Ｐ１、リレー光学系４と折り返しミラー５との間の位置、又は折り返しミラー５とフライアイレンズ６との間の位置等にも配置できる。 Further, as the position where the polarization correction plate 8 is arranged, the light source 1 (in order to suppress unevenness in the amount of light (inclination unevenness) on the irradiated surface 16 by making the incident angle distribution of light with respect to the surface 8a substantially equal to the polarization correction plate 8. Alternatively, the distribution of the incident angles of the light beams on the polarization correction plate 8 in the positions where the light beams from the center of the secondary light source are substantially parallel to the optical axis AX (or the light beams collected at the respective positions of the irradiated surface 16). Are preferably equal to each other). Therefore, the polarization correction plate 8 is not only between the condenser lens 7 and the irradiated surface 16 as in the present embodiment, but also, for example, the position P1 between the filter group 3 and the relay optical system 4, the relay optical system 4 and It can also be arranged at a position between the folding mirror 5 or a position between the folding mirror 5 and the fly-eye lens 6.

偏光補正板８を位置Ｐ１に配置したとき、被照射面１６を照明する照明装置８０は、非偏光な光を発生する光源１と、光源１から発生された光の光路を折り曲げる折り返しミラー５と、その光に対する透過性を有し、折り返しミラー５により増加するその光の偏光度を予め低減させる偏光補正板８と、を備え、偏光補正板８は、光源１の中心から射出された光が照明装置８０の光軸ＡＸに実質的に平行になる位置に配置されることになる。この場合にも、被照射面１６を非偏光な照明光ＩＬで照明できる。この場合には、折り返しミラー５と被照射面１６との間の構成は任意であり、必ずしもオプティカルインテグレータを備える必要もない。   When the polarization correction plate 8 is disposed at the position P1, the illumination device 80 that illuminates the illuminated surface 16 includes the light source 1 that generates non-polarized light, and the folding mirror 5 that bends the optical path of the light generated from the light source 1. A polarization correction plate 8 that has transparency to the light and that reduces in advance the degree of polarization of the light that is increased by the folding mirror 5, and the polarization correction plate 8 receives light emitted from the center of the light source 1. It is disposed at a position substantially parallel to the optical axis AX of the illumination device 80. Also in this case, the irradiated surface 16 can be illuminated with non-polarized illumination light IL. In this case, the configuration between the folding mirror 5 and the irradiated surface 16 is arbitrary, and it is not always necessary to include an optical integrator.

また、本実施形態の照明装置８０は、挿脱回転機構２０に支持された直線偏光板９を有するため、被照射面１６を任意の方向の直線偏光で、かつ光量が同じ光束で照明できる。なお、例えば固体撮像素子の偏光特性等を検査する必要がない場合には、直線偏光板９及び挿脱回転機構２０を設ける必要はない。
また、本実施形態において、被照射面１６に入射する光（撮像素子の照明光）の偏光度は、非偏光を偏光度が０％と見做せる状態と定義したように、偏光度が０％の光に限定されるものではなく、所定の検査に応じた偏光度の照明光となるように偏光補正板８を設置してもよい。例えば、被照射面１６に入射する光の偏光度は１％程度であってもよい。 Moreover, since the illuminating device 80 of this embodiment has the linear polarizing plate 9 supported by the insertion / removal rotation mechanism 20, it can illuminate the irradiated surface 16 with linearly polarized light in an arbitrary direction and the same amount of light. For example, when it is not necessary to inspect the polarization characteristics of the solid-state imaging device, it is not necessary to provide the linearly polarizing plate 9 and the insertion / removal rotation mechanism 20.
In the present embodiment, the degree of polarization of the light incident on the irradiated surface 16 (illumination light from the image sensor) is defined as a state in which non-polarized light can be regarded as having a degree of polarization of 0%. The polarization correction plate 8 may be installed so as to obtain illumination light having a degree of polarization corresponding to a predetermined inspection. For example, the degree of polarization of light incident on the irradiated surface 16 may be about 1%.

なお、上記実施形態では、偏光度がほぼ０％の非偏光な光を発生させる光源（光源１）を用いていたが、偏光度がほぼ０％ではない光（所謂、部分偏光の光、偏光度数％〜１０％程度）を発生させる光源を使用してもよく、又は非偏光な光を発生させる光源と所定の光学部材を組合せて偏光度がほぼ０％ではない光を発生させる構成を採用してもよい。この場合、固体撮像素子（被照射面１６）が非偏光な光で照明されるように偏光補正板８の傾き角αを設定し、偏光補正板８で表面８ａに入射した光の偏光度を変化させる。   In the above embodiment, a light source (light source 1) that generates non-polarized light having a degree of polarization of approximately 0% is used. However, light having a degree of polarization of not approximately 0% (so-called partially polarized light, polarized light). A light source that generates non-polarized light may be used, or a light source that generates non-polarized light and a predetermined optical member may be used to generate light whose degree of polarization is not nearly 0%. May be. In this case, the inclination angle α of the polarization correction plate 8 is set so that the solid-state imaging device (irradiated surface 16) is illuminated with non-polarized light, and the polarization degree of the light incident on the surface 8a by the polarization correction plate 8 is set. Change.

［第２の実施形態］
本発明の第２の実施形態につき図６及び図７を参照して説明する。なお、図６において図１に対応する部分には同一の符号を付してその詳細な説明を省略する。図６は、本実施形態に係る検査装置１００Ａの概略構成を示す。検査装置１００Ａは、ウエハ５０表面の固体撮像素子（検査対象素子）を照明する照明装置８０Ａと、ウエハ５０を移動するプローバ９０と、照明装置８０Ａで照明された検査対象素子の性能を検査するテスタ（不図示）と、主制御装置５３と、照明装置８０Ａの光学部材等を支持するフレーム機構ＦＲとを備えている。 [Second Embodiment]
A second embodiment of the present invention will be described with reference to FIGS. In FIG. 6, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted. FIG. 6 shows a schematic configuration of an inspection apparatus 100A according to the present embodiment. The inspection apparatus 100A includes an illuminating device 80A that illuminates a solid-state image sensor (inspection target element) on the surface of the wafer 50, a prober 90 that moves the wafer 50, and a tester that inspects the performance of the inspection target element illuminated by the illuminating device 80A. (Not shown), a main controller 53, and a frame mechanism FR that supports an optical member and the like of the lighting device 80A.

照明装置８０Ａにおいて、光源１からほぼ＋Ｚ方向に射出された非偏光で広帯域の光束（照明光ＩＬ）は、コレクタレンズ２、フィルタ群３、第１のリレー光学系４Ａを通過し、第１の折り返しミラー５Ａによって光路がほぼ＋Ｘ方向に９０°折り曲げられて、第２のリレー光学系４Ｂに入射する。リレー光学系４Ｂから射出された光束は、第２の折り返しミラー５Ｂによって光路がほぼ−Ｚ方向に９０°折り曲げられて第１のフライアイレンズ６Ａに入射する。フライアイレンズ６Ａから射出された光束は、レンズ２５、及び光軸ＡＸに対してほぼ３５°傾斜した平行平面板の一面にビームスプリッター面（フレネル反射面）が形成されたビームスプリッター３１を介して第２のフライアイレンズ６Ｂに入射する。フライアイレンズ６Ｂから射出された光束は、コンデンサレンズ７及び光軸ＡＸに垂直な平面に対して傾斜した偏光補正板８を介して被照射面１６に入射する。折り返しミラー５Ａ，５Ｂは図１の折り返しミラー５と同様の平面ミラーであり、折り返しミラー５Ａ，５Ｂの反射面は、照明装置８０Ａの光軸ＡＸに対してＹ軸に平行な軸の回りに４５°傾斜している。折り返しミラー５Ａ，５Ｂはそれぞれ光源１の中心からの光束が光軸ＡＸに略平行になる位置に配置されている。光源１から偏光補正板８までの光学部材から照明装置８０Ａの光学系が構成されている。   In the illuminating device 80A, the non-polarized broadband light beam (illumination light IL) emitted from the light source 1 in the substantially + Z direction passes through the collector lens 2, the filter group 3, and the first relay optical system 4A, and passes through the first relay optical system 4A. The optical path is bent approximately 90 ° in the + X direction by the folding mirror 5A, and enters the second relay optical system 4B. The light beam emitted from the relay optical system 4B is incident on the first fly-eye lens 6A after the optical path is bent approximately 90 ° in the −Z direction by the second folding mirror 5B. The light beam emitted from the fly-eye lens 6A passes through the lens 25 and a beam splitter 31 in which a beam splitter surface (Fresnel reflection surface) is formed on one surface of a plane parallel plate inclined approximately 35 ° with respect to the optical axis AX. The light enters the second fly's eye lens 6B. The light beam emitted from the fly-eye lens 6B enters the irradiated surface 16 through the condenser lens 7 and the polarization correction plate 8 inclined with respect to the plane perpendicular to the optical axis AX. The folding mirrors 5A and 5B are flat mirrors similar to the folding mirror 5 of FIG. 1, and the reflecting surfaces of the folding mirrors 5A and 5B are 45 around an axis parallel to the Y axis with respect to the optical axis AX of the illumination device 80A. ° Inclined. The folding mirrors 5A and 5B are respectively arranged at positions where the light beam from the center of the light source 1 is substantially parallel to the optical axis AX. The optical system of the illumination device 80A is composed of optical members from the light source 1 to the polarization correction plate 8.

また、照明装置８０Ａは、ビームスプリッター３１、ビームスプリッター３１で反射（分岐）された光束を集光するレンズ３２、及びその集光された光束を受光する光電センサ３３からなる光量モニター系３０を有する。光量モニター系３０で検出される照明光ＩＬの光量情報は主制御装置５３に出力される。主制御装置５３は、例えばその光量情報に基づいて被照射面１６での照度が所定値になるように光源１の出力を制御、またはＮＤフィルタを制御する。光量モニター系３０のビームスプリッター３１は、レンズ２５とフライアイレンズ６Ｂとの間の、フライアイレンズ６Ａの射出面（瞳面又は二次光源）の中心からの光束が光軸ＡＸに略平行になる位置に配置されている。このようにビームスプリッター３１が設置される位置は、折り返しミラー５Ａ，５Ｂと同様に、光源１又は二次光源の中心からの光束が光軸ＡＸに略平行となる位置（又は被照射面１６の各点に集光する光束が、互いに等しい入射角分布の光束を均等に含むような位置）が望ましい。   The illumination device 80A includes a beam splitter 31, a lens 32 that collects the light beam reflected (branched) by the beam splitter 31, and a light amount monitor system 30 that includes a photoelectric sensor 33 that receives the collected light beam. . Light amount information of the illumination light IL detected by the light amount monitor system 30 is output to the main controller 53. The main controller 53 controls the output of the light source 1 or controls the ND filter so that the illuminance on the irradiated surface 16 becomes a predetermined value based on the light quantity information, for example. The beam splitter 31 of the light quantity monitor system 30 has a light beam from the center of the exit surface (pupil plane or secondary light source) of the fly eye lens 6A between the lens 25 and the fly eye lens 6B substantially parallel to the optical axis AX. It is arranged at the position. The position where the beam splitter 31 is installed in this way is the position where the light beam from the center of the light source 1 or the secondary light source is substantially parallel to the optical axis AX (or the surface of the irradiated surface 16), like the folding mirrors 5A and 5B. It is desirable that the light beam condensed at each point is a position that uniformly includes light beams having the same incident angle distribution.

さらに、照明装置８０Ａは、フライアイレンズ６Ａ，６Ｂ、レンズ２５、ビームスプリッター３１、レンズ３２、及び光電センサ３３を一体的にθｚ方向に回転する第１の回転機構３５と、偏光補正板８及びこの角度調整機構１０を一体的にθｚ方向に回転する第２の回転機構４０とを有する。回転機構３５は、一例として、フレーム機構ＦＲに対して軸受け３７を介して回転対象の光学部材を保持する支持部材３６と、支持部材３６をフレーム機構ＦＲに対して歯車機構３９を介して回転する駆動モータ３８とを有する。同様に、回転機構４０は、フレーム機構ＦＲに対して軸受け４２を介して角度調整機構１０及び偏光補正板８を保持する支持部材４１と、支持部材４１をフレーム機構ＦＲに対して歯車機構４４を介して回転する駆動モータ４３とを有する。主制御装置５３が駆動モータ３８，４３を介して支持部材３６，４１の回転角を制御する。   Furthermore, the illumination device 80A includes a first rotation mechanism 35 that integrally rotates the fly-eye lenses 6A and 6B, the lens 25, the beam splitter 31, the lens 32, and the photoelectric sensor 33 in the θz direction, the polarization correction plate 8 and The angle adjusting mechanism 10 has a second rotating mechanism 40 that integrally rotates in the θz direction. For example, the rotation mechanism 35 rotates the support member 36 with respect to the frame mechanism FR via the gear mechanism 39 and the support member 36 that holds the optical member to be rotated via the bearing 37 with respect to the frame mechanism FR. Drive motor 38. Similarly, the rotation mechanism 40 includes a support member 41 that holds the angle adjustment mechanism 10 and the polarization correction plate 8 via a bearing 42 with respect to the frame mechanism FR, and a gear mechanism 44 that supports the support member 41 with respect to the frame mechanism FR. And a drive motor 43 that rotates via the motor. The main controller 53 controls the rotation angle of the support members 36 and 41 via the drive motors 38 and 43.

次に、図７（ａ）は本実施形態（図６）のウエハ５０表面に整列形成された複数の長方形の固体撮像素子５８（Ｘ方向の長さａ１、Ｙ方向の幅ｂ１とする）の配列の一例を示す。図７（ａ）において、図６の被照射面１６の例えば正方形の照明領域５９の一辺の幅をＡ１とする。また、不図示のテスタで固体撮像素子５８の検査を行う場合、斜線を施したようにＹ方向に１つおきに配置された複数の固体撮像素子５８Ａ〜５８Ｄ等を一度に検査可能であるとする。このとき、一例として、固体撮像素子５８の長さａ１を９．８ｍｍ、幅ｂ１を７．６ｍｍ、照明領域５９の幅Ａ１を４４．６ｍｍとすると、仮に照明領域５９が点線の位置５９Ａで示すように、Ｘ軸又はＹ軸に各辺が平行になるように配置されている場合には、一度に検査可能な固体撮像素子５８Ａ〜５８Ｃは３個である。   Next, FIG. 7A shows a plurality of rectangular solid-state imaging devices 58 (the length a1 in the X direction and the width b1 in the Y direction) aligned on the surface of the wafer 50 of the present embodiment (FIG. 6). An example of the arrangement is shown. In FIG. 7A, the width of one side of the illuminated area 59 of FIG. Further, when the solid-state imaging device 58 is inspected by a tester (not shown), it is possible to inspect a plurality of solid-state imaging devices 58A to 58D, etc., which are arranged every other one in the Y direction as shown by hatching. To do. At this time, as an example, if the length a1 of the solid-state imaging device 58 is 9.8 mm, the width b1 is 7.6 mm, and the width A1 of the illumination area 59 is 44.6 mm, the illumination area 59 is indicated by a dotted line position 59A. Thus, when each side is arranged in parallel to the X axis or the Y axis, there are three solid-state image sensors 58A to 58C that can be inspected at a time.

これに対して本実施形態では、図６の第１の回転機構３５によってフライアイレンズ６Ａ，６Ｂ等をθｚ方向に回転することによって、被照射面１６の照明領域５９を図７（ａ）の実線で示すように（ここではＸ軸に対して４５°傾斜した角度に）回転可能である。この状態では、照明領域５９内に４個の固体撮像素子５８Ａ〜５８Ｄが入るため、一度に４個の固体撮像素子５８の検査が可能になる。なお、回転機構３５がない場合に、一度に４個の固体撮像素子５８の検査を行うには、図７（ｂ）に示すように幅Ａ２が例えば５３．２ｍｍの広い照明領域６０が必要になり、照明装置が大型化してしまう。   On the other hand, in the present embodiment, the fly eye lenses 6A, 6B and the like are rotated in the θz direction by the first rotation mechanism 35 of FIG. As shown by a solid line (here, at an angle inclined by 45 ° with respect to the X axis), it can rotate. In this state, since the four solid-state image sensors 58A to 58D enter the illumination area 59, the four solid-state image sensors 58 can be inspected at a time. In the case where the rotating mechanism 35 is not provided, in order to inspect four solid-state imaging devices 58 at a time, a wide illumination area 60 having a width A2 of, for example, 53.2 mm is required as shown in FIG. 7B. This increases the size of the lighting device.

このように本実施形態では、回転機構３５が設けられているため、被照射面１６の照明領域５９を広くすることなく、より多くの固体撮像素子を一度に検査可能である。
また、本実施形態においては、２段のフライアイレンズ６Ａ，６Ｂを用いるいわゆるダブルフライアイ構成であるため、被照射面１６における照度分布の均一性が向上している。さらに、２枚の折り返しミラー５Ａ，５Ｂを用いることによって、ダブルフライアイ構成で２段のリレー光学系４Ａ，４Ｂを用いていても照明装置８０Ａを小型化できる。 Thus, in the present embodiment, since the rotation mechanism 35 is provided, more solid-state imaging devices can be inspected at a time without widening the illumination area 59 of the irradiated surface 16.
In the present embodiment, since the so-called double fly-eye configuration using the two-stage fly-eye lenses 6A and 6B is used, the uniformity of the illuminance distribution on the irradiated surface 16 is improved. Furthermore, by using the two folding mirrors 5A and 5B, the illuminating device 80A can be reduced in size even when the double-stage relay optical systems 4A and 4B are used in a double fly-eye configuration.

しかしながら、２枚の折り返しミラー５Ａ，５Ｂを用いており、第２の折り返しミラー５Ｂの反射面は、第１の折り返しミラー５Ａの反射面を光軸ＡＸの回りに１８０°回転した面に平行である。言い替えると、折り返しミラー５Ａ，５Ｂの光軸に沿った光の入射面（ＸＺ面）は互いに平行である。また、第１の実施形態の説明より、折り返しミラー５Ａ，５Ｂでは、ｓ偏光（Ｙ方向の偏光）の光に対する反射率がともに大きくなるため、折り返しミラー５Ｂで反射された光束の偏光度は、第１の実施形態の場合のほぼ２倍に悪化する。さらに、本実施形態では、照明光路に配置されている光量モニター系３０のビームスプリッター３１によっても偏光度が変化する。ただし、ビームスプリッター３１では、通常はｐ偏光の光の透過率が高いため、図６の配置のように、例えばビームスプリッター３１が光軸ＡＸに対してθｙ方向に例えばほぼ３５°で傾斜しているときには、ビームスプリッター３１を透過した光束の偏光度は、折り返しミラー５Ｂで反射された直後の光束の偏光度よりもほぼ小さくなる。   However, two folding mirrors 5A and 5B are used, and the reflection surface of the second folding mirror 5B is parallel to a surface obtained by rotating the reflection surface of the first folding mirror 5A by 180 ° around the optical axis AX. is there. In other words, the light incident surfaces (XZ surfaces) along the optical axis of the folding mirrors 5A and 5B are parallel to each other. Further, from the description of the first embodiment, the reflection mirrors 5A and 5B both have high reflectivity with respect to light of s-polarized light (polarized light in the Y direction), so the degree of polarization of the light beam reflected by the reflection mirror 5B is It is almost twice as bad as in the first embodiment. Furthermore, in the present embodiment, the degree of polarization is also changed by the beam splitter 31 of the light amount monitor system 30 arranged in the illumination optical path. However, since the transmittance of the p-polarized light is usually high in the beam splitter 31, for example, the beam splitter 31 is inclined at, for example, approximately 35 ° in the θy direction with respect to the optical axis AX as shown in the arrangement of FIG. The degree of polarization of the light beam transmitted through the beam splitter 31 is substantially smaller than the degree of polarization of the light beam immediately after being reflected by the folding mirror 5B.

しかしながら、本実施形態では、被照射面１６の照明領域５９を回転するために、回転機構３５によってフライアイレンズ６Ａ，６Ｂ及びビームスプリッター３１が一体的に回転される。この結果、ビームスプリッター３１の回転角によっては、ビームスプリッター３１を透過した後の光束の偏光度は複雑に変化し、その偏光度は折り返しミラー５Ｂで反射された後の光束の偏光度よりも高くなることもありえる。   However, in this embodiment, in order to rotate the illumination area 59 of the irradiated surface 16, the fly-eye lenses 6A and 6B and the beam splitter 31 are integrally rotated by the rotation mechanism 35. As a result, depending on the rotation angle of the beam splitter 31, the degree of polarization of the light beam after passing through the beam splitter 31 changes in a complicated manner, and the degree of polarization is higher than the degree of polarization of the light beam after being reflected by the folding mirror 5B. It can be.

そこで、本実施形態では、ビームスプリッター３１を透過した光束の偏光度を小さくするために、コンデンサレンズ７と被照射面１６との間に、光軸ＡＸに垂直な平面に対する傾き角αが調整可能で、かつθｚ方向の回転角が調整可能な偏光補正板８を設けている。本実施形態では、偏光補正板８に入射する光束の偏光度は第１の実施形態の場合よりも増加していることがありえるため、偏光補正板８の傾き角αを小さくするために、偏光補正板８はより屈折率の大きい例えばＳＦ６からなる平行平面板であることが好ましい。   Therefore, in this embodiment, in order to reduce the degree of polarization of the light beam that has passed through the beam splitter 31, the inclination angle α with respect to the plane perpendicular to the optical axis AX can be adjusted between the condenser lens 7 and the irradiated surface 16. And a polarization correction plate 8 capable of adjusting the rotation angle in the θz direction. In the present embodiment, since the degree of polarization of the light beam incident on the polarization correction plate 8 may be higher than that in the first embodiment, in order to reduce the tilt angle α of the polarization correction plate 8, The correction plate 8 is preferably a plane parallel plate made of, for example, SF6 having a higher refractive index.

一例として、検査装置１００Ａの使用開始前に、ステージ５１上に入射光の偏光度を計測できるポラリメータ５７を設置し、ポラリメータ５７を被照射面１６内に移動し、光源１の発光を開始する。そして、主制御装置５３が回転機構３５を介してフライアイレンズ６Ａ，６Ｂ，及びビームスプリッター３１等をθｚ方向に１８０°／Ｎ（Ｎは例えば４以上の整数）回転した状態で、ポラリメータ５７で計測される偏光度の計測値が所定の許容値より小さくなるか、又は最小値になるように、回転機構４０と角度調整機構１０で偏光補正板８の回転角と傾き角αを調整する。具体的には偏光補正板８の傾き角αが０の状態のポラリメータの測定結果の直線偏光方向または楕円偏光長軸方向がｓ偏光になるように、θｚを調整し、その後傾き角αを偏光度の計測値が所定の許容値より小さくなるか、又は最小値になるように調整する。必要があれば、偏光補正板８のθｚ方向における回転角と傾き角αの微調整を繰り返す。そして、回転機構３５による回転角に対応させて回転機構４０による偏光補正板８の回転角及び角度調整機構１０による偏光補正板８の傾き角αを記憶する。その後、回転機構３５を介してビームスプリッター３１等をθｚ方向にさらに１８０°／Ｎ回転して、偏光度の計測値が所定の許容値より小さくなるか、又は最小値になるときの偏光補正板８の回転角及び傾き角αを求めて記憶する動作を回転機構３５による回転角が１８０°になるまで繰り返す。なお、理想的には回転機構３５により１８０°回転した状態は回転前と同じ偏光状態なので、回転機構３５の回転角範囲は０°〜１８０°（−９０°〜９０°）であるが、１８０°回転させるかわりに３６０°回転させてもよい。なお、照野が正方形の場合の照野の回転は９０°で十分なため、回転機構３５の回転角範囲は０°〜９０°（−４５°〜４５°）でもよい。   As an example, before the use of the inspection apparatus 100A is started, a polarimeter 57 that can measure the degree of polarization of incident light is installed on the stage 51, the polarimeter 57 is moved into the irradiated surface 16, and light emission of the light source 1 is started. The main controller 53 rotates the fly-eye lenses 6A and 6B, the beam splitter 31 and the like via the rotation mechanism 35 in the θz direction by 180 ° / N (N is an integer of 4 or more, for example). The rotation angle and the inclination angle α of the polarization correction plate 8 are adjusted by the rotation mechanism 40 and the angle adjustment mechanism 10 so that the measured value of the polarization degree to be measured is smaller than the predetermined allowable value or the minimum value. Specifically, θz is adjusted so that the linear polarization direction or the elliptical polarization long axis direction of the polarimeter measurement result when the inclination angle α of the polarization correction plate 8 is 0 is s-polarized light, and then the inclination angle α is polarized. The measurement value of the degree is adjusted to be smaller than a predetermined allowable value or to a minimum value. If necessary, the fine adjustment of the rotation angle and the inclination angle α in the θz direction of the polarization correction plate 8 is repeated. Then, the rotation angle of the polarization correction plate 8 by the rotation mechanism 40 and the tilt angle α of the polarization correction plate 8 by the angle adjustment mechanism 10 are stored in correspondence with the rotation angle by the rotation mechanism 35. Thereafter, the beam splitter 31 or the like is further rotated 180 ° / N in the θz direction via the rotation mechanism 35, and the polarization correction plate when the measured value of the polarization degree becomes smaller than the predetermined allowable value or becomes the minimum value. The operation of obtaining and storing the rotation angle 8 and the inclination angle α is repeated until the rotation angle by the rotation mechanism 35 reaches 180 °. Ideally, the state rotated by 180 ° by the rotation mechanism 35 is the same polarization state as before rotation, so the rotation angle range of the rotation mechanism 35 is 0 ° to 180 ° (−90 ° to 90 °), but 180 Instead of rotating, it may be rotated 360 °. Since the rotation of the illumination field is 90 ° when the illumination field is square, the rotation angle range of the rotation mechanism 35 may be 0 ° to 90 ° (−45 ° to 45 °).

その後、検査装置１００Ａを用いてウエハ５０表面の固体撮像素子の検査を行う際に、回転機構３５を介して被照射面１６の照明領域５９を回転したときには、その回転角に応じて被照射面１６上での偏光度が小さくなるように、回転機構４０及び角度調整機構１０を介して偏光補正板８の回転角及び傾き角αを調整する。これによって、白色で非偏光な照明光ＩＬを使用したときに、照明領域５９を任意の方向に回転しても、照明領域５９に照射される光束を非偏光にできる。本実施例では折り返しミラー５Ａと５Ｂ及びビームスプリッター３１が光学部材１に対応する。   Thereafter, when the solid-state imaging device on the surface of the wafer 50 is inspected using the inspection apparatus 100A, when the illumination area 59 of the irradiated surface 16 is rotated via the rotation mechanism 35, the irradiated surface is selected according to the rotation angle. The rotation angle and the inclination angle α of the polarization correction plate 8 are adjusted via the rotation mechanism 40 and the angle adjustment mechanism 10 so that the degree of polarization on the surface 16 is reduced. Accordingly, when white and non-polarized illumination light IL is used, even if the illumination area 59 is rotated in an arbitrary direction, the light beam applied to the illumination area 59 can be made non-polarized. In this embodiment, the folding mirrors 5A and 5B and the beam splitter 31 correspond to the optical member 1.

また、被照射面１６を照明する照明装置８０Ａは、非偏光な光を発生する光源１と、光源１からの光が入射するフライアイレンズ６Ｂと、光源１からの光の一部を折り曲げるビームスプリッター３１と、フライアイレンズ６Ｂにおける光の射出面からの光で被照射面１６を略テレセントリックにケーラー照明するコンデンサレンズ７と、コンデンサレンズ７と被照射面１６との間に配置され、その光に対する透過性を有し、折り返しミラー５Ａ，５Ｂ及びビームスプリッター３１により増加する光の偏光度を低減させる平行平面板よりなる偏光補正板８と、を備えている。照明装置８０Ａによれば、被照射面１６を非偏光な光で照明できる。この場合には、折り返しミラー５Ａ，５Ｂは必ずしも設けられていなくともよい。   The illumination device 80A that illuminates the illuminated surface 16 includes a light source 1 that generates non-polarized light, a fly-eye lens 6B that receives light from the light source 1, and a beam that bends part of the light from the light source 1. A splitter 31, a condenser lens 7 that performs Koehler illumination of the irradiated surface 16 in a substantially telecentric manner with light from the light exit surface of the fly-eye lens 6 </ b> B, and the condenser lens 7 and the irradiated surface 16. And a polarization correction plate 8 made of a plane parallel plate that reduces the degree of polarization of light that is increased by the folding mirrors 5A and 5B and the beam splitter 31. According to the illumination device 80A, the illuminated surface 16 can be illuminated with non-polarized light. In this case, the folding mirrors 5A and 5B are not necessarily provided.

なお、本実施形態において、偏光補正板８は、光源１の中心からの光束が光軸ＡＸに略平行になる位置に配置してもよい。また、本実施形態では、折り返しミラー５Ａ，５Ｂが設けられていない場合でも、偏光補正板８を設けることによって、光量モニター系３０のビームスプリッター３１によって生じる偏光度を補正することができる。   In the present embodiment, the polarization correction plate 8 may be disposed at a position where the light beam from the center of the light source 1 is substantially parallel to the optical axis AX. In the present embodiment, even when the folding mirrors 5A and 5B are not provided, the degree of polarization generated by the beam splitter 31 of the light quantity monitor system 30 can be corrected by providing the polarization correction plate 8.

なお、本実施形態においても、偏光度がほぼ０％ではない光（所謂、部分偏光の光、偏光度数％〜１０％程度）を発生させる光源を使用してもよく、又は非偏光な光を発生させる光源と所定の光学部材を組合せて偏光度がほぼ０％ではない光を発生させる構成を採用してもよい。この場合、固体撮像素子（被照射面１６）が非偏光な光で照明されるように、偏光補正板８の傾き角α及びθz方向における回転角を設定し、偏光補正板８で表面８ａに入射した光の偏光度を変化させる。   Also in this embodiment, a light source that generates light whose polarization degree is not nearly 0% (so-called partially polarized light, polarization degree of about 10% to 10%) may be used, or unpolarized light is used. A configuration in which light having a degree of polarization not substantially 0% may be generated by combining a light source to be generated and a predetermined optical member. In this case, the rotation angles in the tilt angles α and θz directions of the polarization correction plate 8 are set so that the solid-state imaging device (irradiated surface 16) is illuminated with non-polarized light, and the polarization correction plate 8 causes the surface 8a. The degree of polarization of incident light is changed.

［第３の実施形態］
本発明の第３の実施形態につき図８を参照して説明する。なお、図８において図１及び図６に対応する部分には同一の符号を付してその詳細な説明を省略する。図８は、本実施形態に係る照明装置８０Ｂの概略構成を示す。照明装置８０Ｂは、例えば図１の検査装置１００の照明装置として使用可能である。 [Third Embodiment]
A third embodiment of the present invention will be described with reference to FIG. In FIG. 8, portions corresponding to those in FIGS. 1 and 6 are denoted by the same reference numerals, and detailed description thereof is omitted. FIG. 8 shows a schematic configuration of the illumination device 80B according to the present embodiment. The illumination device 80B can be used as, for example, the illumination device of the inspection device 100 in FIG.

照明装置８０Ｂにおいて、光源１からほぼ＋Ｙ方向に射出された非偏光で広帯域の光束（照明光ＩＬ）は、コレクタレンズ２、フィルタ群３、第１のリレー光学系４Ａを通過し、第１の折り返しミラー５Ａによって光路がほぼ＋Ｘ方向に９０°折り曲げられて、第２のリレー光学系４Ｂに入射する。リレー光学系４Ｂから射出された光束は、第２の折り返しミラー５Ｃによって光路がほぼ−Ｚ方向に９０°折り曲げられてフライアイレンズ６に入射する。フライアイレンズ６から射出された光束は、コンデンサレンズ７を介して被照射面に入射する。光源１からコンデンサレンズ７までの光学部材から照明装置８０Ｂの光学系が構成されている。   In the illumination device 80B, the non-polarized broadband light beam (illumination light IL) emitted from the light source 1 in the substantially + Y direction passes through the collector lens 2, the filter group 3, and the first relay optical system 4A, and the first relay optical system 4A. The optical path is bent approximately 90 ° in the + X direction by the folding mirror 5A, and enters the second relay optical system 4B. The light beam emitted from the relay optical system 4B is incident on the fly-eye lens 6 after the optical path is bent approximately 90 ° in the −Z direction by the second folding mirror 5C. The light beam emitted from the fly-eye lens 6 enters the irradiated surface via the condenser lens 7. An optical system of the illumination device 80B is composed of optical members from the light source 1 to the condenser lens 7.

本実施形態において、折り返しミラー５Ａ，５Ｃは図１の折り返しミラー５と同様の平面ミラーであるが、折り返しミラー５Ａの反射面５Ａａは、照明装置８０ＢのＹ軸に平行な光軸に対してθｚ方向に４５°傾斜しており、折り返しミラー５Ｃの反射面５Ｃａは、照明装置８０ＢのＸ軸に平行な光軸に対してＹ軸に平行な軸の回りに４５°傾斜している。言い替えると、第２の折り返しミラー５Ｃの反射面５Ｃａは、第１の折り返しミラー５Ａの反射面５Ａａを光軸ＡＸの回りに時計回りに９０°回転した面に平行である。この結果、光軸ＡＸに平行な光束に関して、折り返しミラー５Ａの入射面（ＸＹ面）と折り返しミラー５Ｃの入射面（ＸＺ面）とは垂直に交差しているため、折り返しミラー５Ａに関してｓ偏光（又はｐ偏光）となる光は折り返しミラー５Ｃに関してはｐ偏光（又はｓ偏光）となる。   In this embodiment, the folding mirrors 5A and 5C are plane mirrors similar to the folding mirror 5 in FIG. 1, but the reflecting surface 5Aa of the folding mirror 5A is θz with respect to the optical axis parallel to the Y axis of the illumination device 80B. The reflecting surface 5Ca of the folding mirror 5C is inclined 45 ° around an axis parallel to the Y axis with respect to the optical axis parallel to the X axis of the illumination device 80B. In other words, the reflecting surface 5Ca of the second folding mirror 5C is parallel to a surface obtained by rotating the reflecting surface 5Aa of the first folding mirror 5A by 90 ° clockwise around the optical axis AX. As a result, with respect to the light flux parallel to the optical axis AX, the incident surface (XY surface) of the folding mirror 5A and the incident surface (XZ surface) of the folding mirror 5C intersect perpendicularly. (Or p-polarized light) becomes p-polarized light (or s-polarized light) with respect to the folding mirror 5C.

本実施形態において、第１の実施形態の説明より、折り返しミラー５Ａでは、ｓ偏光（ここではＺ方向の偏光）の光に対する反射率が大きくなるが、そのｓ偏光の光は折り返しミラー５Ｃではｐ偏光となって反射率が小さくなる。つまり、折り返しミラー５Ａで反射された光束の偏光度の変化(偏光度の増加分)が、折り返しミラー５Ｃにおける反射により、低減される。従って、２枚の折り返しミラー５Ａ，５Ｃを用いて照明装置８０Ｂを小型化できるとともに、光源１から発生される非偏光な光束の偏光度の変化(偏光度の増加)が抑制でき、被照射面を広帯域でかつ非偏光な光束で照明できる。   In the present embodiment, from the description of the first embodiment, the reflection mirror 5A has a higher reflectance with respect to light of s-polarized light (here, polarization in the Z direction), but the light of s-polarized light is p in the reflection mirror 5C. It becomes polarized light and the reflectance becomes small. That is, a change in the degree of polarization of the light beam reflected by the folding mirror 5A (an increase in the degree of polarization) is reduced by reflection at the folding mirror 5C. Accordingly, the illumination device 80B can be miniaturized using the two folding mirrors 5A and 5C, and the change in the degree of polarization of the non-polarized light beam generated from the light source 1 (increase in the degree of polarization) can be suppressed. Can be illuminated with a broadband and non-polarized light beam.

また、折り返しミラー５Ａ，５Ｃやその他の光学部材で生じた光の偏光度をより抑制する場合は、上記第１の実施形態及び第２の実施形態と同様に偏光補正板８を用いることができる。この場合、偏光補正板８は、照明装置８０Ｂのコンデンサレンズ７と被照射面１６との間において、照明装置８０Ｂの光学系の光軸ＡＸに垂直な平面に対して斜めに配置される。   Further, in the case where the degree of polarization of light generated by the folding mirrors 5A and 5C and other optical members is further suppressed, the polarization correction plate 8 can be used as in the first and second embodiments. . In this case, the polarization correction plate 8 is disposed obliquely with respect to a plane perpendicular to the optical axis AX of the optical system of the illumination device 80B, between the condenser lens 7 of the illumination device 80B and the irradiated surface 16.

偏光補正板８の光軸ＡＸに垂直な平面に対する傾き角αは、被照射面に入射する光の直線偏光成分の大きさに基づいて、被照射面１６に入射する光が可能な限り非偏光な光となるように決定する。また、偏光補正板８のθｚ方向における回転角は被照射面に入射する光の直線偏光成分の方位に基づいて決定する。   The inclination angle α with respect to the plane perpendicular to the optical axis AX of the polarization correction plate 8 is based on the magnitude of the linearly polarized light component incident on the irradiated surface, and the light incident on the irradiated surface 16 is as non-polarized as possible. Decide to be a light. The rotation angle of the polarization correction plate 8 in the θz direction is determined based on the direction of the linearly polarized light component of the light incident on the irradiated surface.

照明装置８０Ｂは不図示の角度調整機構を有し、偏光補正板８の傾き角αと偏光補正板８のθｚ方向における回転角を調整する。なお、偏光補正板８の傾き角αと偏光補正板８のθｚ方向における回転角は、一度調整した後は固定することも可能である。   The illumination device 80B has an angle adjustment mechanism (not shown) and adjusts the tilt angle α of the polarization correction plate 8 and the rotation angle of the polarization correction plate 8 in the θz direction. Note that the inclination angle α of the polarization correction plate 8 and the rotation angle of the polarization correction plate 8 in the θz direction can be fixed once adjusted.

なお、偏光補正板８は、コンデンサレンズ７と被照射面１６との間の他に、例えばフィルタ群３と第１のリレー光学系４Ａとの間の位置、第１のリレー光学系４Ａと折り返しミラー５Ａとの間の位置、折り返しミラー５Ａと第２のリレー光学系４Ｂとの間の位置、第２のリレー光学系４Ｂと折り返しミラー５Ｂとの間の位置、又は折り返しミラー５Ｂとフライアイレンズ６との間の位置にも配置できる。   Note that the polarization correction plate 8 is not only between the condenser lens 7 and the irradiated surface 16 but also at a position between, for example, the filter group 3 and the first relay optical system 4A, or folded with the first relay optical system 4A. A position between the mirror 5A, a position between the folding mirror 5A and the second relay optical system 4B, a position between the second relay optical system 4B and the folding mirror 5B, or a folding mirror 5B and a fly-eye lens. It can also be arranged at a position between 6.

なお、本実施形態では、第２の折り返しミラー５Ｃの反射面５Ｃａは、第１の折り返しミラー５Ａの反射面５Ａａを光軸ＡＸの回りに時計回りに９０°回転した面に平行であるため、折り返しミラー５Ａで生じる偏光度を最も良好に低減できる。しかしながら、第２の折り返しミラー５Ｃの反射面５Ｃａは、第１の折り返しミラー５Ａの反射面５Ａａを光軸ＡＸの回りに９０°以外の角度で回転した面に平行であってもよい。この場合でも、偏光補正板８により被照射面１６に入射する光の偏光度を低減できる。
また、上記の各実施形態では、オプティカルインテグレータとしてフライアイレンズが使用されているが、オプティカルインテグレータとしては、ロッドインテグレータ又はロッドインテグレータとフライアイレンズとの組み合わせ等も使用可能である。 In the present embodiment, the reflecting surface 5Ca of the second folding mirror 5C is parallel to a surface obtained by rotating the reflecting surface 5Aa of the first folding mirror 5A by 90 ° clockwise around the optical axis AX. The degree of polarization generated in the folding mirror 5A can be reduced most favorably. However, the reflecting surface 5Ca of the second folding mirror 5C may be parallel to a surface obtained by rotating the reflecting surface 5Aa of the first folding mirror 5A around the optical axis AX at an angle other than 90 °. Even in this case, the polarization correction plate 8 can reduce the degree of polarization of light incident on the irradiated surface 16.
In each of the above embodiments, a fly-eye lens is used as the optical integrator. However, as the optical integrator, a rod integrator or a combination of a rod integrator and a fly-eye lens can be used.

次に、上記の実施形態の検査装置１００又は１００Ａを用いて撮像素子（固体撮像素子）を製造する方法の一例につき図９のフローチャートを参照して説明する。図９のステップＳ４０１（パターン形成工程）では、先ず、露光対象のウエハ（図１のウエハ５０）にフォトレジストを塗布して感光基板を準備する塗布工程、露光装置（不図示）を用いて撮像素子用のマスクのパターンをその感光基板上の多数のパターン形成領域に転写露光する露光工程、その感光基板を現像する現像工程を含むフォトリソグラフィー工程によって、そのウエハ上に所定のレジストパターンが形成される。このフォトリソグラフィー工程に続いて、そのレジストパターンをマスクとしたエッチング工程、ＣＶＤ工程、及びレジスト剥離工程等を経て、そのウエハ上に多数の電極等を含む多数の固体撮像素子の回路パターンが形成される。そのフォトリソグラフィー工程等は、そのウエハ上のレイヤ数に応じて複数回実行される。   Next, an example of a method for manufacturing an image sensor (solid-state image sensor) using the inspection apparatus 100 or 100A of the above embodiment will be described with reference to the flowchart of FIG. In step S401 (pattern formation process) in FIG. 9, first, an image is picked up using an exposure apparatus (not shown), an application process in which a photoresist is applied to a wafer to be exposed (wafer 50 in FIG. 1) to prepare a photosensitive substrate. A predetermined resist pattern is formed on the wafer by a photolithographic process including an exposure process in which an element mask pattern is transferred and exposed to a number of pattern forming regions on the photosensitive substrate, and a developing process in which the photosensitive substrate is developed. The Subsequent to this photolithography process, a circuit pattern of a large number of solid-state imaging devices including a large number of electrodes and the like is formed on the wafer through an etching process, a CVD process, a resist stripping process, and the like using the resist pattern as a mask. The The photolithography process or the like is executed a plurality of times according to the number of layers on the wafer.

その次のステップＳ４０２（カラーフィルタ形成工程）では、赤Ｒ、緑Ｇ、青Ｂに対応した３つの微細なフィルタの組をマトリクス状に多数配列するか、又は赤Ｒ、緑Ｇ、青Ｂの３本のストライプ状の複数のフィルタの組を水平走査線方向に配列することによって、ウエハ表面の多数の固体撮像素子の多数の画素に対応させてカラーフィルタを形成する。その次のステップＳ４０３（検査工程）では、上記の実施形態の検査装置１００，１００Ａを用いてウエハ表面の多数の固体撮像素子の性能検査を行う。   In the next step S402 (color filter forming step), a large number of three fine filter groups corresponding to red R, green G, and blue B are arranged in a matrix or red R, green G, and blue B are arranged. By arranging a set of three stripe-shaped filters in the horizontal scanning line direction, a color filter is formed corresponding to a large number of pixels of a large number of solid-state imaging elements on the wafer surface. In the next step S403 (inspection process), performance inspection of a large number of solid-state imaging devices on the wafer surface is performed using the inspection apparatuses 100 and 100A of the above-described embodiment.

その後のステップＳ４０４（モジュール組立工程）では、そのようにして検査に合格した素子をウエハから切り離し、保護基板等に取り付け、さらにリード端子等を取り付けて、固体撮像素子として完成させる。
上述の撮像素子の製造方法によれば、上記の実施形態の検査装置を用いて固体撮像素子を検査する工程を含んでおり、その検査装置では非偏光な検査光又は偏光方位によらずに光量が均一な直線偏光の検査光を使用できるため、製造された固体撮像素子の性能検査を高精度に行うことができる。従って、高性能の固体撮像素子を製造できる。 In subsequent step S404 (module assembly process), the element that has passed the inspection in this manner is separated from the wafer, attached to a protective substrate, etc., and further, lead terminals and the like are attached to complete the solid-state imaging element.
According to the above-described method for manufacturing an image sensor, the process includes a step of inspecting a solid-state image sensor using the inspection apparatus of the above-described embodiment, and the inspection apparatus uses a non-polarized inspection light or a light amount regardless of the polarization direction. Since uniform inspection light with linearly polarized light can be used, performance inspection of the manufactured solid-state imaging device can be performed with high accuracy. Therefore, a high-performance solid-state image sensor can be manufactured.

なお、図９の撮像素子（固体撮像素子）の製造方法では、ステップ４０２（カラーフィルタ形成工程）の後にステップ４０３（検査工程）にて上記実施形態の検査装置１００, １００Ａを用いて固体撮像素子の性能検査を行うこととしたが、固体撮像素子の性能検査は、ステップ４０２（カラーフィルタ形成工程）の後に限らず、例えば、ステップ４０１（パターン形成工程）とステップ４０２（カラーフィルタ形成工程）との間に実施してもよい。   In the method of manufacturing the image sensor (solid-state image sensor) in FIG. 9, the solid-state image sensor is used in step 403 (inspection process) after step 402 (color filter forming process) using the inspection apparatuses 100 and 100A of the above embodiment. However, the performance inspection of the solid-state imaging device is not limited to after step 402 (color filter forming process), and for example, step 401 (pattern forming process) and step 402 (color filter forming process) You may carry out between.

なお、本発明は上述の実施形態に限定されず、本発明の要旨を逸脱しない範囲で種々の構成を取り得る。   In addition, this invention is not limited to the above-mentioned embodiment, A various structure can be taken in the range which does not deviate from the summary of this invention.

１…光源、２…コレクタレンズ、３…フィルタ群、４，４Ａ，４Ｂ…リレー光学系、５，５Ａ〜５Ｃ…折り返しミラー、６，６Ａ，６Ｂ…フライアイレンズ、７…コンデンサレンズ、８…偏光補正板、９…直線偏光板、１０…角度調整機構、１６…被照射面、２０…挿脱回転機構、５０…ウエハ（半導体ウエハ）、５６…テスタ、５８…固体撮像素子、８０，８０Ａ，８０Ｂ…照明装置、９０…プローバ、１００，１００Ａ…検査装置   DESCRIPTION OF SYMBOLS 1 ... Light source, 2 ... Collector lens, 3 ... Filter group, 4, 4A, 4B ... Relay optical system, 5, 5A-5C ... Folding mirror, 6, 6A, 6B ... Fly eye lens, 7 ... Condenser lens, 8 ... Polarization correction plate, 9 ... linearly polarizing plate, 10 ... angle adjustment mechanism, 16 ... irradiated surface, 20 ... insertion / removal rotation mechanism, 50 ... wafer (semiconductor wafer), 56 ... tester, 58 ... solid-state imaging device, 80, 80A , 80B ... lighting device, 90 ... prober, 100,100A ... inspection device

Claims (8)

被検査物を検査する検査装置において、
光源から発生した光が入射する第１光学部材と、
前記光に対する透過性を有し、前記被検査物へ非偏光な光が入射するように前記光の偏光度を変化させる第２光学部材と、を有する照明装置と、
前記照明装置からの光で照明された前記被検査物からの出力を検出し、該検出の結果に基づいて前記被検査物を検査する検査部と、
を備え、
前記第２光学部材は、前記光源の中心から射出された光が前記照明装置の光軸に実質的に平行になる位置に配置されるとともに、
前記第２光学部材は、板状光学部材を含み、前記照明装置の光軸に垂直な面に対して傾斜して配置されたことを特徴とする検査装置。 In an inspection device for inspecting an object to be inspected,
A first optical member on which light generated from a light source enters;
A second optical member having transparency to the light and changing a degree of polarization of the light so that non-polarized light is incident on the inspection object;
Detecting an output from the inspection object illuminated with light from the illumination device, and inspecting the inspection object based on a result of the detection; and
With
The second optical member is disposed at a position where the light emitted from the center of the light source is substantially parallel to the optical axis of the illumination device ,
2. The inspection apparatus according to claim 1, wherein the second optical member includes a plate-like optical member and is inclined with respect to a plane perpendicular to the optical axis of the illumination device. 前記板状光学部材は、任意の方位において、前記照明装置の光軸に垂直な面に対する傾斜角が可変であることを特徴とする請求項１に記載の検査装置。 The inspection apparatus according to claim 1 , wherein the plate-like optical member has a variable inclination angle with respect to a plane perpendicular to the optical axis of the illumination apparatus in an arbitrary direction. 前記第１光学部材は、ビームスプリッターを含むことを特徴とする請求項１又は２に記載の検査装置。 Wherein the first optical member inspection apparatus according to claim 1 or 2, characterized in that it comprises a beam splitter. 前記照明装置は、
前記光源からの光が入射するオプティカルインテグレータと、
前記オプティカルインテグレータにおける光の射出面からの光を前記被検査物へ略テレセントリックにケーラー照明するコンデンサレンズと、を更に有することを特徴とする請求項１〜３のいずれか一項に記載の検査装置。 The lighting device includes:
An optical integrator on which light from the light source is incident;
Inspection apparatus according to any one of claims 1 to 3, further comprising a, a condenser lens for Kohler illumination in a substantially telecentric light to the inspection object from the exit surface of the light in the optical integrator . 被検査物を検査する検査装置において、
光源から発生した光が入射する第１光学部材と、
前記光に対する透過性を有し、前記被検査物へ非偏光な光が入射するように前記光の偏光度を変化させる第２光学部材と、を有する照明装置と、
前記照明装置からの光で照明された前記被検査物からの出力を検出し、該検出の結果に基づいて前記被検査物を検査する検査部と、
を備え、
前記第２光学部材は、前記光源の中心から射出された光が前記照明装置の光軸に実質的に平行になる位置に配置されるとともに、
前記照明装置は、
前記光源からの光が入射するオプティカルインテグレータと、
前記オプティカルインテグレータにおける光の射出面からの光を前記被検査物へ略テレセントリックにケーラー照明するコンデンサレンズと、を更に有することを特徴とする検査装置。 In an inspection device for inspecting an inspection object,
A first optical member on which light generated from a light source enters;
A second optical member having transparency to the light and changing a degree of polarization of the light so that non-polarized light is incident on the inspection object;
Detecting an output from the inspection object illuminated with light from the illumination device, and inspecting the inspection object based on a result of the detection; and
With
The second optical member is disposed at a position where the light emitted from the center of the light source is substantially parallel to the optical axis of the illumination device ,
The lighting device includes:
An optical integrator on which light from the light source is incident;
An inspection apparatus further comprising: a condenser lens that irradiates light from the light exit surface of the optical integrator to the object to be inspected approximately telecentricly . 前記第２光学部材は、前記光源と前記オプティカルインテグレータとの間に配置されたことを特徴とする請求項４又は５に記載の検査装置。 The inspection apparatus according to claim 4, wherein the second optical member is disposed between the light source and the optical integrator. 前記照明装置は前記光源を更に有すると共に、前記被検査物を載置するステージを更に備えることを特徴とする請求項１〜６のいずれか一項に記載の検査装置。   The inspection apparatus according to claim 1, wherein the illumination device further includes the light source, and further includes a stage on which the inspection object is placed. 請求項１〜７のいずれか一項に記載の検査装置で撮像素子の検査を行う工程を含むことを特徴とする撮像素子の製造方法。
The manufacturing method of an image pick-up element characterized by including the process of test | inspecting an image pick-up element with the test | inspection apparatus as described in any one of Claims 1-7.
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