JP2005315742A - Measuring apparatus and measuring method - Google Patents

Measuring apparatus and measuring method Download PDF

Info

Publication number
JP2005315742A
JP2005315742A JP2004134278A JP2004134278A JP2005315742A JP 2005315742 A JP2005315742 A JP 2005315742A JP 2004134278 A JP2004134278 A JP 2004134278A JP 2004134278 A JP2004134278 A JP 2004134278A JP 2005315742 A JP2005315742 A JP 2005315742A
Authority
JP
Japan
Prior art keywords
light
measured
pattern
light receiving
measuring apparatus
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2004134278A
Other languages
Japanese (ja)
Inventor
Hideo Shimizu
秀夫 清水
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sony Corp
Original Assignee
Sony Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sony Corp filed Critical Sony Corp
Priority to JP2004134278A priority Critical patent/JP2005315742A/en
Publication of JP2005315742A publication Critical patent/JP2005315742A/en
Pending legal-status Critical Current

Links

Images

Landscapes

  • Length Measuring Devices By Optical Means (AREA)
  • Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)
  • Testing Or Measuring Of Semiconductors Or The Like (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To provide a measuring apparatus and a measuring method which enables the measurement of the line widths and cross-sectional shapes of a large number of patterns to be measured at a time. <P>SOLUTION: Incident light from a light source 2 is reflected in different directions by a plurality of reflecting plates 31 of a light dispersing means 3 to irradiate a plurality of patterns to be measured 11 of a substrate to be measured 10 with beams of reflected light each. The patterns to be measured 11 are, for example, constituted of line and space patterns. When light is emitted to the patterns to be measured 11 of the substrate to be measured 10, diffracted light is generated from each pattern to be measured, passed through an optical system 5, and received by a light receiving means 6. A data processing means 7 is previously provided with theoretical spectra to reference shapes and specifies the line widths or cross-sectional profiles of the patterns to be measured 11 by retrieving the theoretical spectrum most close to the spectrum of detected diffracted light. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は、測定装置および測定方法に関し、特に、光を用いてパターンのＣＤ（Critical Dimension) や、断面形状を測定する測定装置および測定方法に関する。   The present invention relates to a measuring apparatus and a measuring method, and more particularly to a measuring apparatus and a measuring method for measuring a pattern CD (Critical Dimension) and a cross-sectional shape using light.

半導体集積回路のパターンの微細化に伴い、パターンの線幅測定における測定精度が要求されている。また、測定装置には、高精度のみならず、歩留り低下要因を早期に検出する高速かつ非破壊の機能が要求されている。   With the miniaturization of patterns in semiconductor integrated circuits, measurement accuracy in pattern line width measurement is required. Further, the measuring apparatus is required to have not only high accuracy but also a high-speed and non-destructive function for early detection of a yield reduction factor.

さらに、測定結果を元にプロセスの最適化のためのフィードバックへの適用が可能な測定装置も求められている。その結果、測定装置は従来の独立型のものでなく、製造と同時に測定を行う装置組み込み型（ＩＭ：Integrated Metrology) が強く要求されている。   There is also a need for a measuring device that can be applied to feedback for process optimization based on measurement results. As a result, there is a strong demand for a measurement device that is not a conventional stand-alone type, but a device built-in type (IM: Integrated Metrology) that performs measurement simultaneously with manufacturing.

従来ＣＤ測定には、走査型電子顕微鏡（ＳＥＭ：Scanning Electron Microscope) や原子間力顕微鏡といった装置が使用されてきた。この中で、測長ＳＥＭはウエハ上部からＣＤを測定することができ、製造現場においてもっとも一般的であった。しかし、近年になって線幅微細化に対応する精度の不足や、測定におけるレジストの電子線損傷が無視できなくなってきている。また、ＳＥＭは真空装置であるため小型化は困難であり、ＩＭ化への要求には対応が難しい。   Conventionally, devices such as a scanning electron microscope (SEM) and an atomic force microscope have been used for CD measurement. Among them, the length measuring SEM can measure the CD from the upper part of the wafer, and is the most common at the manufacturing site. However, in recent years, it has become impossible to ignore the lack of accuracy corresponding to the fine line width and the electron beam damage of the resist in the measurement. Further, since the SEM is a vacuum apparatus, it is difficult to reduce the size, and it is difficult to meet the demand for IM.

このような背景にあって、光の散乱を用いたスキャトロメトリー（ＯＣＤ（Optical Critical Dimension) あるいはＯＤＰ（Optical Digital Profilometry) などとも称される）が、次世代測定技術として用いられつつある（特許文献１参照）。   Against this background, scatterometry using light scattering (also called OCD (Optical Critical Dimension) or ODP (Optical Digital Profilometry)) is being used as the next generation measurement technology (patents) Reference 1).

スキャトロメトリーは、レジストパターンの線幅をＳＥＭなどに比較して短時間で測定できるのみならず、同時に断面形状等も計測できる。また、大気中で測定するため、現像装置に組み込まれる等して露光装置へのフィードバックにも利用可能であるとして期待されている。   In scatterometry, not only can the line width of a resist pattern be measured in a short time compared to SEM or the like, but also the cross-sectional shape and the like can be measured simultaneously. In addition, since the measurement is performed in the atmosphere, it is expected that it can be used for feedback to an exposure apparatus by being incorporated in a developing apparatus.

図７は、従来の測定装置（スキャトロメトリー）の概略構成を示す図である。   FIG. 7 is a diagram showing a schematic configuration of a conventional measuring apparatus (scatterometry).

図７に示す測定装置は、光源１０１と、偏光子を含む光学系１０２と、光学系１０３と、受光手段１０４とを有する。被測定パターン１１０は、例えば、数十μｍ角の領域に配置された、一定のピッチで繰り返されるラインアンドスペースパターンである。   The measuring apparatus illustrated in FIG. 7 includes a light source 101, an optical system 102 including a polarizer, an optical system 103, and a light receiving unit 104. The pattern to be measured 110 is a line and space pattern which is arranged in a region of several tens of μm square and is repeated at a constant pitch, for example.

図７に示す測定装置では、光源１０１から照射されたブロードバンド光が光学系１０２により直線偏向にされて、被測定パターン１１０へ入射される。被測定パターン１１０からの回折光が光学系１０３を通って受光手段１０４により受光される。   In the measuring apparatus shown in FIG. 7, the broadband light emitted from the light source 101 is linearly deflected by the optical system 102 and is incident on the measured pattern 110. Diffracted light from the pattern to be measured 110 is received by the light receiving means 104 through the optical system 103.

被測定パターン１１０の線幅、断面形状、材質によって回折光のスペクトルが変化することから、予め蓄積したスペクトルと比較することにより、被測定パターン１１０の線幅、断面形状が特定される。
特開２０００−１１４１６６号公報 Since the spectrum of the diffracted light changes depending on the line width, cross-sectional shape, and material of the pattern to be measured 110, the line width and cross-sectional shape of the pattern to be measured 110 are specified by comparing with the spectrum accumulated in advance.
JP 2000-114166 A

しかしながら、上記の従来の測定装置では、一度に１箇所（１つの被測定パターン１１０）しか測定することができず、短時間といえども１箇所の測定に３０秒程度かかるため、多数の箇所の測定が必要な場合には、時間がかかるという問題があった。   However, the above-described conventional measuring apparatus can measure only one place (one pattern 110 to be measured) at a time and takes about 30 seconds to measure one place even in a short time. When measurement is necessary, there is a problem that it takes time.

露光ショット内のフォーカスのモニタリングなどを行う場合には多数の箇所の測定が必要であることから、従来の測定装置では、現像装置等に組み込み、量産レベルで露光条件等のプロセス条件にフィードバックすることが困難であるという問題がある。   When monitoring focus within an exposure shot, etc., it is necessary to measure a large number of locations. Therefore, with conventional measurement equipment, it is built into the development equipment and fed back to process conditions such as exposure conditions at the mass production level. There is a problem that is difficult.

本発明は上記の事情に鑑みてなされたものであり、その目的は、一度に多数の被測定パターンの線幅や断面形状を測定することができる測定装置および測定方法を提供することにある。   The present invention has been made in view of the above circumstances, and an object thereof is to provide a measuring apparatus and a measuring method capable of measuring the line widths and cross-sectional shapes of a large number of patterns to be measured at once.

上記の目的を達成するため、本発明の測定装置は、光源と、前記光源からの入射光を複数に分割し、分割した光を被測定基板の複数の被測定パターンにそれぞれ照射させる光分割手段と、各被測定パターンからの反射あるいは回折光を検出する受光手段と、前記受光手段により検出された光強度に基づいて、各被測定パターンの線幅あるいは断面形状を特定するデータ処理手段とを有する。   In order to achieve the above object, a measuring apparatus according to the present invention includes a light source and a light dividing unit that divides incident light from the light source into a plurality of light beams and irradiates the divided light beams to a plurality of measured patterns on a measured substrate And light receiving means for detecting reflected or diffracted light from each measured pattern, and data processing means for specifying the line width or cross-sectional shape of each measured pattern based on the light intensity detected by the light receiving means. Have.

上記の本発明の測定装置によれば、光源からの入射光は、光分割手段により、複数に分割され、分割された光は被測定基板の複数の被測定パターンにそれぞれ照射される。
被測定基板の各被測定パターンに光が照射されると、各被測定パターンから反射あるいは回折光が発生し、受光手段により受光される。
受光手段により検出された光強度に基づいて、データ処理手段により、各被測定パターンの線幅あるいは断面形状が特定される。 According to the measurement apparatus of the present invention, the incident light from the light source is divided into a plurality of parts by the light dividing means, and the divided lights are respectively irradiated to the plurality of patterns to be measured on the substrate to be measured.
When light is irradiated to each measured pattern of the measured substrate, reflected or diffracted light is generated from each measured pattern and received by the light receiving means.
Based on the light intensity detected by the light receiving means, the line width or cross-sectional shape of each pattern to be measured is specified by the data processing means.

上記の目的を達成するため、本発明の測定方法は、光を複数に分割し、分割した光を被測定基板の複数の被測定パターンにそれぞれ照射させるステップと、各被測定パターンからの反射あるいは回折光を検出するステップと、検出された光強度に基づいて、各被測定パターンの線幅あるいは断面形状を特定するステップとを有する。   In order to achieve the above object, the measurement method of the present invention divides light into a plurality of parts, irradiates the divided light onto a plurality of measured patterns on the measured substrate, and reflects or reflects from each measured pattern. The method includes a step of detecting diffracted light and a step of specifying the line width or cross-sectional shape of each pattern to be measured based on the detected light intensity.

上記の本発明の測定方法によれば、１つの光が複数に分割され、分割された光は、被測定基板の複数の被測定パターンにそれぞれ照射される。
被測定基板の各被測定パターンに光が照射されると、各被測定パターンから反射あるいは回折光が発生する。
各被測定パターンからの反射あるいは回折光を検出し、検出された光強度に基づいて、各被測定パターンの線幅あるいは断面形状が特定される。 According to the measurement method of the present invention described above, one light is divided into a plurality of pieces, and the divided lights are respectively irradiated onto a plurality of patterns to be measured on the substrate to be measured.
When light is irradiated to each measured pattern of the measured substrate, reflected or diffracted light is generated from each measured pattern.
Reflected or diffracted light from each measured pattern is detected, and the line width or cross-sectional shape of each measured pattern is specified based on the detected light intensity.

本発明の測定装置および測定方法によれば、一度に多数の被測定パターンの線幅や断面形状を測定することができる。   According to the measuring apparatus and the measuring method of the present invention, the line widths and cross-sectional shapes of a large number of patterns to be measured can be measured at a time.

以下に、本発明の測定装置および測定方法の実施の形態について、図面を参照して説明する。本実施形態では、スキャトロメトリーと称される測定装置を例に説明する。なお、スキャトロメトリーはＯＣＤ（Optical Critical Dimension) あるいはＯＤＰ（Optical
Digital Profilometry) などとも称される。 Embodiments of a measuring apparatus and a measuring method of the present invention will be described below with reference to the drawings. In the present embodiment, a measurement device called scatterometry will be described as an example. Scatterometry can be performed using OCD (Optical Critical Dimension) or ODP (Optical
Digital Profilometry).

（第１実施形態）
図１は、本実施形態に係る測定装置の構成を示す図である。図２は、測定装置に用いられる受光手段の構成を示す図である。 (First embodiment)
FIG. 1 is a diagram illustrating a configuration of a measuring apparatus according to the present embodiment. FIG. 2 is a diagram showing the configuration of the light receiving means used in the measuring apparatus.

図１に示す測定装置１は、光源２と、光分割手段３と、光学系４と、光学系５と、受光手段６と、データ処理手段７とを有する。   A measuring apparatus 1 shown in FIG. 1 includes a light source 2, a light splitting unit 3, an optical system 4, an optical system 5, a light receiving unit 6, and a data processing unit 7.

光源２は、例えば数ｃｍ以上の径をもつブロードバンド光を照射する。光源２は、例え、可視光やＵＶ光を照射する白色光源である。   The light source 2 emits broadband light having a diameter of, for example, several centimeters or more. The light source 2 is, for example, a white light source that emits visible light or UV light.

光分割手段３は、光源２からの光を複数の方向に反射するよう、複数の異なる角度をもった反射板（反射部）３１を備える。光源２から複数の反射板３１に光が一括照射されると、それぞれの反射板３１の角度に応じて複数の反射光が別の方向に進行する。光源２からの入射光に対する各反射板３１の角度を調整しておくことにより、被測定基板１０内の所望の位置に複数の入射光が同時に照射される。   The light splitting means 3 includes a plurality of reflecting plates (reflecting portions) 31 having different angles so as to reflect light from the light source 2 in a plurality of directions. When light is collectively irradiated from the light source 2 to the plurality of reflecting plates 31, the plurality of reflected lights travel in different directions according to the angles of the respective reflecting plates 31. By adjusting the angle of each reflection plate 31 with respect to the incident light from the light source 2, a plurality of incident lights are simultaneously irradiated to a desired position in the substrate 10 to be measured.

光学系４は、例えば反射板３１からの各反射光を直線偏光にする偏光子を複数備える。光学系４に入射した複数の反射光は、直線偏光の入射光に変換される。   The optical system 4 includes, for example, a plurality of polarizers that make each reflected light from the reflecting plate 31 linearly polarized light. The plurality of reflected lights incident on the optical system 4 are converted into linearly polarized incident light.

被測定基板１０には、直線偏光となった複数の入射光が照射される位置に、それぞれ被測定パターン１１が設けられている。被測定パターン１１は、繰り返しパターンにより構成される。   The measurement target substrate 10 is provided with a measurement pattern 11 at a position where a plurality of incident light beams that are linearly polarized light are irradiated. The measured pattern 11 is composed of a repeating pattern.

図３は、被測定パターン１１の構成を示す要部断面図である。図３（ａ）に示すように、繰り返しパターンからなる被測定パターン１１は、例えば、被測定基板１０上の被加工層２０をエッチングするためのレジストパターン２１により構成される。あるいは、図３（ｂ）に示すように、被測定パターン１１は、レジストパターン２１を用いて被加工層２０をエッチングした後の加工パターン２０ａにより構成される。被測定パターン１１は、例えば、数十μｍ角の領域に配置された、一定のピッチで繰り返されるラインアンドスペースパターンであるが、それ以外にもコンタクトホールパターンであってもよい。   FIG. 3 is a cross-sectional view of the main part showing the configuration of the pattern to be measured 11. As shown in FIG. 3A, the pattern to be measured 11 composed of a repetitive pattern is constituted by, for example, a resist pattern 21 for etching the processing layer 20 on the substrate to be measured 10. Alternatively, as shown in FIG. 3B, the measured pattern 11 includes a processed pattern 20 a after the processed layer 20 is etched using the resist pattern 21. The pattern to be measured 11 is, for example, a line-and-space pattern arranged in a region of several tens of μm square and repeated at a constant pitch, but may be a contact hole pattern.

被測定基板１０の各被測定パターン１１に光がそれぞれ照射されると、各被測定パターン１１の各膜界面で透過、屈折、回折を繰り返し、入射角と同じ出射角の方向に０次回折光が発生する。０次回折光はパターンに依存するため、０次回折光を正確に解析することによって、測定対象である被測定パターン１１の線幅や断面形状を特定することができる。   When each measured pattern 11 of the measured substrate 10 is irradiated with light, transmission, refraction, and diffraction are repeated at each film interface of each measured pattern 11, and 0th-order diffracted light is emitted in the direction of the same emission angle as the incident angle. Occur. Since the 0th-order diffracted light depends on the pattern, the line width and the cross-sectional shape of the measured pattern 11 to be measured can be specified by accurately analyzing the 0th-order diffracted light.

被測定パターン１１からの回折光は、光学系５を通って受光手段６に受光され、回折光のスペクトルが検出される。回折光の位相変化状態も解析し得るように、例えば、光学系５は、１／４波長板、検光子、グレーティングを備える。   The diffracted light from the pattern to be measured 11 is received by the light receiving means 6 through the optical system 5, and the spectrum of the diffracted light is detected. For example, the optical system 5 includes a quarter-wave plate, an analyzer, and a grating so that the phase change state of the diffracted light can be analyzed.

受光手段６は、図２に示すように、被測定パターン１１からの回折光を同時に検出するため、各被測定パターン１１からの回折光の入射位置に受光素子６１を備える。回折光は、被測定パターン１１のピッチに依存して進行する方向が変化する。ただし、被測定基板１０内の被測定パターン１１の位置、すなわち回折光の発生する位置は決まっているため、受光素子６１間の位置関係は固定されていても検出可能である。   As shown in FIG. 2, the light receiving means 6 includes a light receiving element 61 at the incident position of the diffracted light from each measured pattern 11 in order to simultaneously detect the diffracted light from the measured pattern 11. The direction in which the diffracted light travels depends on the pitch of the pattern to be measured 11. However, since the position of the pattern 11 to be measured in the substrate 10 to be measured, that is, the position where the diffracted light is generated is determined, it can be detected even if the positional relationship between the light receiving elements 61 is fixed.

従って、本実施形態では、受光素子６１を４つ取り付けた受光手段６を、回折光の角度に応じて移動させる。本実施形態に係る測定装置１をプロセスのモニターとして用いる場合は、サンプルで最初に４つの受光素子６１を備える受光手段６の位置合わせをしておくことにより、その後は、ほぼ同じ方向に回折光が出るため受光手段６の微調整を行うことで対応可能である。   Therefore, in this embodiment, the light receiving means 6 to which the four light receiving elements 61 are attached is moved according to the angle of the diffracted light. When the measuring apparatus 1 according to this embodiment is used as a process monitor, the light receiving means 6 including the four light receiving elements 61 is first aligned in the sample, and thereafter, the diffracted light is directed in substantially the same direction. Can be dealt with by fine adjustment of the light receiving means 6.

データ処理手段７は、パターンの線幅、断面形状、材質毎に、予めシミュレーションした理論スペクトルをライブラリーとして蓄積している。データ処理手段７は、受光手段６により得られた０次回折光のスペクトルの信号に基づいて、回折光の測定スペクトルに最も近い、理論スペクトルを検索する。そして、当該理論スペクトルを得るために用いた、パターンの線幅、断面形状を、被測定パターン１１の線幅、断面形状として特定する。   The data processing means 7 accumulates theoretical spectra simulated in advance as a library for each line width, cross-sectional shape, and material of the pattern. The data processing means 7 searches for the theoretical spectrum closest to the measured spectrum of the diffracted light based on the spectrum signal of the 0th-order diffracted light obtained by the light receiving means 6. Then, the line width and cross-sectional shape of the pattern used to obtain the theoretical spectrum are specified as the line width and cross-sectional shape of the pattern to be measured 11.

本実施形態に係る測定装置１による測定手順について、図４のフローチャートを参照して説明する。   A measurement procedure by the measurement apparatus 1 according to the present embodiment will be described with reference to the flowchart of FIG.

図４に示すフローチャートは、ステップＳＴ１〜ＳＴ３のオフラインプロセスと、ステップＳＴ４〜ＳＴ５のオンラインプロセスよりなる。   The flowchart shown in FIG. 4 includes an offline process in steps ST1 to ST3 and an online process in steps ST4 to ST5.

まず、各形状パラメータ値を設定する（ステップＳＴ１）。形状パラメータ値とは、測定対象が取りうる形状を特定するパラメータである。形状パラメータ値として、測定対象（被測定パターン）の線幅、断面形状、材質を複数設定する。   First, each shape parameter value is set (step ST1). The shape parameter value is a parameter that specifies a shape that the measurement target can take. A plurality of line widths, cross-sectional shapes, and materials of the measurement target (pattern to be measured) are set as shape parameter values.

次に、各形状パラメータ値をもつパターンについて、光学シミュレーションを行うことにより、特定の形状パラメータ値をもつパターンに光を照射した場合に得られる回折光のスペクトルを解析する。光学シミュレーションには、例えば、厳密電磁波解析（ＲＣＷＡ：Rigorous Coupled Wave Analysis) を用いる。   Next, an optical simulation is performed on the pattern having each shape parameter value, thereby analyzing the spectrum of the diffracted light obtained when the pattern having the specific shape parameter value is irradiated with light. For the optical simulation, for example, strict electromagnetic wave analysis (RCWA) is used.

ＲＣＷＡでは、パターン形状を左右対象な平板の組み合わせで近似し、まず、パターンの周期的な構造、および対応する電場をフーリエ級数で表現する。ＲＣＷＡでは、この周期構造に既知の状態の光が入射した時に発生する回折をベクトル波として扱い、マクスウェル方程式で表す。そして、得られたマクスウェル方程式を境界条件に従って固有値問題に書き換えて解を求める。これにより、０次回折光の理論スペクトルが求まる。   In RCWA, a pattern shape is approximated by a combination of left and right flat plates. First, a periodic structure of a pattern and a corresponding electric field are expressed by a Fourier series. In RCWA, diffraction that occurs when light in a known state is incident on this periodic structure is treated as a vector wave, and is represented by the Maxwell equation. Then, the obtained Maxwell equation is rewritten into an eigenvalue problem according to the boundary condition to obtain a solution. Thereby, the theoretical spectrum of the 0th-order diffracted light is obtained.

ＲＣＷＡを用いてある構造に対する光学シミュレーションを行うことが可能であるが、変数が非常に多いため、測定で得られた０次回折光の信号から、測定対象の構造を直接計算することができない。そこで、ライブラリー方式と称される方式が取られる。すなわち、様々なパターン形状について光学シミュレーションすることにより得られた理論スペクトラムをライブラリーとして蓄積しておく（ステップＳＴ３）。   Although it is possible to perform an optical simulation for a certain structure using RCWA, since there are so many variables, the structure of the measurement object cannot be directly calculated from the 0th-order diffracted light signal obtained by the measurement. Therefore, a method called a library method is taken. In other words, theoretical spectra obtained by optical simulation of various pattern shapes are stored as a library (step ST3).

そして、オンラインプロセスにおいて、被測定パターン１１からの回折光の測定スペクトルを得たら、データ処理手段７により、予め蓄積された理論スペクトルの中から、測定スペクトルに最も近い理論スペクトルを検索する。最も近い理論スペクトルを解析する際に用いた形状パラメータ値により、被測定パターン１１の線幅や断面形状が特定される。ライブラリー方式の場合、オンラインプロセスでは検索時間のみで足りるため、非常に高速に処理できるという利点がある。   Then, in the online process, when the measurement spectrum of the diffracted light from the pattern to be measured 11 is obtained, the data processor 7 searches the theoretical spectrum closest to the measurement spectrum from the theoretical spectra accumulated in advance. The line width and cross-sectional shape of the pattern to be measured 11 are specified by the shape parameter value used when analyzing the closest theoretical spectrum. The library method has an advantage that it can be processed at a very high speed because the online process requires only the search time.

以上説明したように、本実施形態に係る測定装置および測定方法によれば、一度に多数の被測定パターン１１へ光を照射し、被測定パターン１１からの各回折光を同時に検出することができることから、複数の被測定パターン１１の線幅や断面形状の測定のスループットを向上させることができる。このため、現像装置等に組み込み、量産レベルで露光条件等のプロセス条件に迅速にフィードバックすることが可能となる。   As described above, according to the measuring apparatus and the measuring method according to the present embodiment, it is possible to irradiate a large number of patterns 11 to be measured at a time and simultaneously detect each diffracted light from the patterns 11 to be measured. Thus, the throughput of measurement of the line widths and cross-sectional shapes of the plurality of measured patterns 11 can be improved. For this reason, it can be incorporated into a developing device or the like, and can be quickly fed back to process conditions such as exposure conditions at the mass production level.

本実施形態に係る測定装置の第１の応用対象は、欠陥パターン検出および原因分類である。形状に関連するパラメータの許容上限と下限を設定し、その範囲を逸脱したウエハ等の被測定基板１０を検知すること、あるいは変動の傾向を把握して、必要であれば警告を発するといった利用方法である。   The first application object of the measuring apparatus according to the present embodiment is defect pattern detection and cause classification. Usage method of setting an allowable upper limit and a lower limit of parameters related to the shape, detecting the measurement target substrate 10 such as a wafer that deviates from the range, or grasping the tendency of fluctuation and issuing a warning if necessary. It is.

また、レジストパターン形状は露光量、フォーカスと相関があることが分かっているため、本実施形態に係る測定装置１による形状結果に基づき、最適露光量、フォーカスをフィードバックすることにも利用することができる。   Further, since it is known that the resist pattern shape has a correlation with the exposure amount and the focus, it can be used to feed back the optimum exposure amount and the focus based on the shape result by the measuring apparatus 1 according to the present embodiment. it can.

また、現像後ベークの温度、塗布膜厚均一性等もパターン形状に影響する。このような多変量の関係を解明し、フィードバックすることによってスロット毎のコントロールや、ウエハ毎のコントロールが可能になる。   Further, post-development baking temperature, coating film thickness uniformity, etc. also affect the pattern shape. By elucidating and feeding back such a multivariate relationship, control for each slot and control for each wafer becomes possible.

（第２実施形態）
第１実施形態に係る測定装置は、測定可能な位置を固定しているため、デバイスパターンをそれに合わせて設計し、所望の位置に数十μｍ角の被測定パターン１１を配置する例である。第２実施形態では、測定可能な位置を固定することなく、任意の複数箇所の測定を可能とする測定装置および測定方法を提供する。 (Second Embodiment)
The measurement apparatus according to the first embodiment is an example in which a measurable position is fixed, so that a device pattern is designed in accordance with that, and a measured pattern 11 of several tens of μm square is arranged at a desired position. In the second embodiment, a measuring apparatus and a measuring method are provided that enable measurement at an arbitrary plurality of locations without fixing measurable positions.

図５は、本実施形態に係る測定装置の概略構成図である。第１実施形態と同じ構成要素には同じ符号を付してあり、その説明は省略する。   FIG. 5 is a schematic configuration diagram of a measuring apparatus according to the present embodiment. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

本実施形態では、光分割手段３には、光源２からの入射光に対する反射面の角度を調整可能に構成された可動反射板３２を備える。可動反射板３２の反射面は、それぞれ機械的に制御可能に構成される。これにより、被測定基板１０内への光の照射位置を任意に調整可能となる。   In the present embodiment, the light dividing means 3 includes a movable reflecting plate 32 configured to be able to adjust the angle of the reflecting surface with respect to incident light from the light source 2. The reflecting surface of the movable reflecting plate 32 is configured to be mechanically controllable. Thereby, the irradiation position of the light into the to-be-measured substrate 10 can be arbitrarily adjusted.

光学系４ａは、例えば可動反射板３２からの各反射光を直線偏光にする偏光子を複数備える。本実施形態では、可動反射板３２からの反射光をそれぞれ直線偏向にし、被測定パターン１１へ導くように、複数の偏向子の位置が機械的に制御可能に構成される。   The optical system 4a includes a plurality of polarizers that make each reflected light from the movable reflecting plate 32 linearly polarized light, for example. In the present embodiment, the positions of the plurality of deflectors are configured to be mechanically controllable so that the reflected light from the movable reflector 32 is linearly deflected and guided to the pattern 11 to be measured.

被測定パターン１１からの回折光は、光学系５を通って受光手段６に受光され、回折光のスペクトルが検出される。例えば、光学系５は、１／４波長板、検光子、グレーティングを備えるが、被測定パターン１１からの回折光の入射位置の変化に対応するため、これらの光学素子の位置が機械的に制御可能に構成される。   The diffracted light from the pattern to be measured 11 is received by the light receiving means 6 through the optical system 5, and the spectrum of the diffracted light is detected. For example, the optical system 5 includes a quarter-wave plate, an analyzer, and a grating. However, in order to cope with a change in the incident position of the diffracted light from the measured pattern 11, the positions of these optical elements are mechanically controlled. Configured to be possible.

受光手段６は、図６（ａ）に示すように、可動受光素子６２を備える。可動受光素子６２は、回折光の入射位置の変化に対応すべく平面内での位置を機械的に制御可能に構成されている。   The light receiving means 6 includes a movable light receiving element 62 as shown in FIG. The movable light receiving element 62 is configured such that the position in the plane can be mechanically controlled in response to the change in the incident position of the diffracted light.

なお、第１実施形態と同様に、測定装置１をプロセスのモニターとして用いる場合は、サンプルで最初に受光手段６の位置および可動受光素子６２の相対位置を調整しておくことにより、その後は、ほぼ同じ方向に回折光が出るため受光手段６の微調整を行うことで対応可能である。   As in the first embodiment, when the measuring apparatus 1 is used as a process monitor, the position of the light receiving means 6 and the relative position of the movable light receiving element 62 are first adjusted with a sample, and thereafter, Since diffracted light is emitted in substantially the same direction, it can be dealt with by fine adjustment of the light receiving means 6.

あるいは、図６（ｂ）に示すように、マトリックス状に複数の受光素子６３を取り付け、４つの回折光の全てを同時に測定できるような構成の受光手段６を採用してもよい。   Alternatively, as shown in FIG. 6B, a plurality of light receiving elements 63 may be attached in a matrix shape, and the light receiving means 6 configured to be able to measure all four diffracted lights simultaneously may be employed.

本実施形態に係る測定装置１によれば、被測定基板１０の任意の箇所を測定することが可能であるため、被測定基板１０内の被測定パターン１１の位置が変更しても対応可能である。従って、デバイスパターンの設計の自由度を制限することなく、第１実施形態と同様の効果を奏することができる。   According to the measuring apparatus 1 according to the present embodiment, it is possible to measure an arbitrary portion of the substrate 10 to be measured, and therefore it is possible to cope with a change in the position of the pattern 11 to be measured in the substrate 10 to be measured. is there. Therefore, the same effects as those of the first embodiment can be obtained without limiting the degree of freedom in designing the device pattern.

本発明は、上記の実施形態の説明に限定されない。
例えば、本実施形態では、４つの被測定パターン１１を測定する例について説明したが、被測定パターン１１の数に限定はなく、従って、反射板の数および受光素子の数は種々の変更が可能である。また、本実施形態では、被測定パターン１１として繰り返しパターンを用い、被測定パターン１１からの回折光を検出する例について説明したが、被測定パターン１１からの反射光を検出してもよい。この場合には、被測定パターン１１として、繰り返しパターン以外の他のパターンを採用することができる。 The present invention is not limited to the description of the above embodiment.
For example, in the present embodiment, an example in which four measured patterns 11 are measured has been described. However, the number of measured patterns 11 is not limited, and therefore the number of reflectors and the number of light receiving elements can be variously changed. It is. In the present embodiment, an example in which a repetitive pattern is used as the measured pattern 11 and the diffracted light from the measured pattern 11 is detected has been described. However, reflected light from the measured pattern 11 may be detected. In this case, a pattern other than the repeated pattern can be adopted as the measured pattern 11.

また、ブロードバンド光を照射する光源２を使用し、光分割手段３は反射板を備える例について説明したが、光分割手段３は、光源からの入射光を複数に分割し、分割した光を被測定基板１０の複数の被測定パターン１１にそれぞれ照射させるものであれば限定はない。   Moreover, although the light source 2 which irradiates broadband light was used and the light splitting means 3 was provided with the reflecting plate, the light splitting means 3 splits the incident light from the light source into a plurality of parts and receives the split light. There is no limitation as long as each of the plurality of patterns to be measured 11 on the measurement substrate 10 is irradiated.

例えば、レーザ光を採用することも可能である。レーザ光を採用する場合には、光分割手段３としてビームスプリッタを用いて、レーザ光を分割すればよい。また、データ処理手段７によるデータ処理方法として、ライブラリー方式を採用する例について説明したが、多変量回帰方式を採用してもよい。   For example, laser light can be used. When laser light is used, the laser light may be split using a beam splitter as the light splitting means 3. Moreover, although the example which employ | adopts a library system as a data processing method by the data processing means 7 was demonstrated, you may employ | adopt a multivariate regression system.

多変量回帰方式では、データベースはもたずに、基準形状に対する理論スペクトルの光学シミュレーション、理論スペクトルと実測スペクトルとの比較、誤差算出という手順を、予め決められた誤差範囲に収束するまで繰り返す手法である。ただし、収束誤差を小さく設定すると、多変量回帰分析に要する時間が長くなるため、スループットの向上の観点からは、短時間で処理可能なライブラリー方式を採用することが好ましい。
その他、本発明の要旨を逸脱しない範囲で、種々の変更が可能である。 The multivariate regression method does not have a database, but repeats the steps of optical simulation of the theoretical spectrum with respect to the reference shape, comparison between the theoretical spectrum and the measured spectrum, and error calculation until convergence to a predetermined error range. is there. However, if the convergence error is set to be small, the time required for multivariate regression analysis becomes long. Therefore, from the viewpoint of improving throughput, it is preferable to adopt a library method that can be processed in a short time.
In addition, various modifications can be made without departing from the scope of the present invention.

第１実施形態に係る測定装置の構成を示す図である。It is a figure which shows the structure of the measuring apparatus which concerns on 1st Embodiment. 第１実施形態に係る測定装置に用いられる受光手段の構成図である。It is a block diagram of the light-receiving means used for the measuring apparatus which concerns on 1st Embodiment. 被測定パターンの構成を示す要部断面図である。It is principal part sectional drawing which shows the structure of a to-be-measured pattern. 本実施形態に係る測定装置による測定手順を示すフローチャートである。It is a flowchart which shows the measurement procedure by the measuring apparatus which concerns on this embodiment. 第２実施形態に係る測定装置の概略構成図である。It is a schematic block diagram of the measuring apparatus which concerns on 2nd Embodiment. 第２実施形態に係る測定装置に用いられる受光手段の構成図である。It is a block diagram of the light-receiving means used for the measuring apparatus which concerns on 2nd Embodiment. 従来例の測定装置の概略構成図である。It is a schematic block diagram of the measuring apparatus of a prior art example.

符号の説明Explanation of symbols

１…測定装置、２…光源、３…光分割手段、４，４ａ…光学系、５，５ａ…光学系、６…受光手段、７…データ処理手段、１０…被測定基板、１１…被測定パターン、２０…被加工層、２０ａ…加工パターン、２１…レジストパターン、３１…反射板、３２…可動反射板、６１…受光素子、６２…可動受光素子、６３…受光素子、１０１…光源、１０２…光学系、１０３…光学系、１０４…受光手段、１１０…被測定パターン
DESCRIPTION OF SYMBOLS 1 ... Measuring apparatus, 2 ... Light source, 3 ... Light splitting means, 4, 4a ... Optical system, 5, 5a ... Optical system, 6 ... Light receiving means, 7 ... Data processing means, 10 ... Substrate to be measured, 11 ... Measured Pattern, 20 ... layer to be processed, 20a ... processing pattern, 21 ... resist pattern, 31 ... reflector, 32 ... movable reflector, 61 ... light receiving element, 62 ... movable light receiving element, 63 ... light receiving element, 101 ... light source, 102 ... Optical system, 103 ... Optical system, 104 ... Light receiving means, 110 ... Pattern to be measured

Claims (9)

光源と、
前記光源からの入射光を複数に分割し、分割した光を被測定基板の複数の被測定パターンにそれぞれ照射させる光分割手段と、
各被測定パターンからの反射あるいは回折光を検出する受光手段と、
前記受光手段により検出された光強度に基づいて、各被測定パターンの線幅あるいは断面形状を特定するデータ処理手段と
を有する測定装置。 A light source;
A light splitting means for splitting the incident light from the light source into a plurality of pieces and irradiating the divided light onto the plurality of measured patterns of the substrate to be measured;
A light receiving means for detecting reflected or diffracted light from each measured pattern;
And a data processing means for specifying a line width or a cross-sectional shape of each pattern to be measured based on the light intensity detected by the light receiving means. 前記光分割手段は、前記光源からの入射光を異なる方向に反射させて、各反射光を前記被測定基板の複数の前記被測定パターンにそれぞれ照射させる複数の反射部を有する
請求項１記載の測定装置。 The said light splitting means has a some reflection part which reflects the incident light from the said light source in a different direction, and irradiates each said reflected light to the said to-be-measured pattern of the said to-be-measured substrate, respectively. measuring device. 前記反射部は、前記被測定基板への反射光の照射位置を調整し得るように、前記光源からの入射光に対する反射面の角度を調整可能に構成された
請求項２記載の測定装置。 The measurement apparatus according to claim 2, wherein the reflection unit is configured to be capable of adjusting an angle of a reflection surface with respect to incident light from the light source so that an irradiation position of reflected light to the measurement target substrate can be adjusted. 前記受光手段は、各被測定パターンからの反射あるいは回折光を別々に検出する複数の受光素子を有する
請求項１記載の測定装置。 The measuring apparatus according to claim 1, wherein the light receiving unit includes a plurality of light receiving elements for separately detecting reflected or diffracted light from each pattern to be measured. 前記複数の受光素子は、反射あるいは回折光の受光位置を調整し得るように移動可能に構成された
請求項４記載の測定装置。 The measuring apparatus according to claim 4, wherein the plurality of light receiving elements are configured to be movable so as to adjust a light receiving position of reflected or diffracted light. 前記受光手段は、各被測定パターンからの反射あるいは回折光を同時に検出するマトリックス状に配置された複数の受光素子を有する
請求項１記載の測定装置。 The measuring apparatus according to claim 1, wherein the light receiving unit includes a plurality of light receiving elements arranged in a matrix that simultaneously detects reflection or diffracted light from each pattern to be measured. 前記データ処理手段は、予め被測定パターンの線幅あるいは断面形状に応じた前記反射あるいは回折光の理論強度値を複数備え、前記受光手段により検出された光強度に最も近い理論強度値を検索し、当該理論強度値に対応する線幅あるいは断面形状を、被測定パターンの線幅あるいは断面形状として特定する
請求項１記載の測定装置。 The data processing means has a plurality of theoretical intensity values of the reflected or diffracted light corresponding to the line width or cross-sectional shape of the pattern to be measured in advance, and searches for the theoretical intensity value closest to the light intensity detected by the light receiving means. The measuring apparatus according to claim 1, wherein the line width or cross-sectional shape corresponding to the theoretical intensity value is specified as the line width or cross-sectional shape of the pattern to be measured. 前記被測定パターンとして繰り返しパターンを用いる
請求項１記載の測定装置。 The measuring apparatus according to claim 1, wherein a repeated pattern is used as the pattern to be measured. 光を複数に分割し、分割した光を被測定基板の複数の被測定パターンにそれぞれ照射させるステップと、
各被測定パターンからの反射あるいは回折光を検出するステップと、
検出された光強度に基づいて、各被測定パターンの線幅あるいは断面形状を特定するステップと
を有する測定方法。 Dividing the light into a plurality of pieces, and irradiating the plurality of measured patterns on the measured substrate with the divided lights, and
Detecting reflected or diffracted light from each measured pattern;
A step of identifying a line width or a cross-sectional shape of each pattern to be measured based on the detected light intensity.
JP2004134278A 2004-04-28 2004-04-28 Measuring apparatus and measuring method Pending JP2005315742A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2004134278A JP2005315742A (en) 2004-04-28 2004-04-28 Measuring apparatus and measuring method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2004134278A JP2005315742A (en) 2004-04-28 2004-04-28 Measuring apparatus and measuring method

Publications (1)

Publication Number Publication Date
JP2005315742A true JP2005315742A (en) 2005-11-10

Family

ID=35443328

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2004134278A Pending JP2005315742A (en) 2004-04-28 2004-04-28 Measuring apparatus and measuring method

Country Status (1)

Country Link
JP (1) JP2005315742A (en)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007285923A (en) * 2006-04-18 2007-11-01 Jordan Valley Semiconductors Ltd Measurement of critical dimensions using x-ray diffraction in reflection mode
WO2007132758A1 (en) * 2006-05-17 2007-11-22 Tokyo Electron Limited Substrate treating method, program, computer-readable storage medium, and substrate treating system
JP2008166734A (en) * 2006-11-30 2008-07-17 Asml Netherlands Bv Method and device for inspection, lithographic device, lithographic processing cell, and method for manufacturing device
JP2008249686A (en) * 2007-01-16 2008-10-16 Asml Netherlands Bv Inspection method and apparatus, lithographic apparatus, lithographic processing cell, and device manufacturing method
US8243878B2 (en) 2010-01-07 2012-08-14 Jordan Valley Semiconductors Ltd. High-resolution X-ray diffraction measurement with enhanced sensitivity
JP2013253881A (en) * 2012-06-07 2013-12-19 Fujitsu Semiconductor Ltd Pattern inspection method and pattern inspection device
JP2014025929A (en) * 2012-07-24 2014-02-06 Snu Precision Co Ltd Thickness measurement device and method using digital optical technique
US8687766B2 (en) 2010-07-13 2014-04-01 Jordan Valley Semiconductors Ltd. Enhancing accuracy of fast high-resolution X-ray diffractometry
US8781070B2 (en) 2011-08-11 2014-07-15 Jordan Valley Semiconductors Ltd. Detection of wafer-edge defects
JP2016170133A (en) * 2015-03-16 2016-09-23 株式会社東芝 Imaging apparatus and imaging method
JP2017518496A (en) * 2014-05-28 2017-07-06 コーニング インコーポレイテッド System and method for inspecting an object
US9726624B2 (en) 2014-06-18 2017-08-08 Bruker Jv Israel Ltd. Using multiple sources/detectors for high-throughput X-ray topography measurement

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007285923A (en) * 2006-04-18 2007-11-01 Jordan Valley Semiconductors Ltd Measurement of critical dimensions using x-ray diffraction in reflection mode
WO2007132758A1 (en) * 2006-05-17 2007-11-22 Tokyo Electron Limited Substrate treating method, program, computer-readable storage medium, and substrate treating system
US7884950B2 (en) 2006-05-17 2011-02-08 Tokyo Electron Limited Substrate processing method, program, computer-readable storage medium, and substrate processing system
JP2008166734A (en) * 2006-11-30 2008-07-17 Asml Netherlands Bv Method and device for inspection, lithographic device, lithographic processing cell, and method for manufacturing device
JP2008249686A (en) * 2007-01-16 2008-10-16 Asml Netherlands Bv Inspection method and apparatus, lithographic apparatus, lithographic processing cell, and device manufacturing method
JP2011040772A (en) * 2007-01-16 2011-02-24 Asml Netherlands Bv Inspection method
US8243878B2 (en) 2010-01-07 2012-08-14 Jordan Valley Semiconductors Ltd. High-resolution X-ray diffraction measurement with enhanced sensitivity
US8731138B2 (en) 2010-01-07 2014-05-20 Jordan Valley Semiconductor Ltd. High-resolution X-ray diffraction measurement with enhanced sensitivity
US8693635B2 (en) 2010-07-13 2014-04-08 Jordan Valley Semiconductor Ltd. X-ray detector assembly with shield
US8687766B2 (en) 2010-07-13 2014-04-01 Jordan Valley Semiconductors Ltd. Enhancing accuracy of fast high-resolution X-ray diffractometry
US8781070B2 (en) 2011-08-11 2014-07-15 Jordan Valley Semiconductors Ltd. Detection of wafer-edge defects
JP2013253881A (en) * 2012-06-07 2013-12-19 Fujitsu Semiconductor Ltd Pattern inspection method and pattern inspection device
JP2014025929A (en) * 2012-07-24 2014-02-06 Snu Precision Co Ltd Thickness measurement device and method using digital optical technique
JP2017518496A (en) * 2014-05-28 2017-07-06 コーニング インコーポレイテッド System and method for inspecting an object
US9726624B2 (en) 2014-06-18 2017-08-08 Bruker Jv Israel Ltd. Using multiple sources/detectors for high-throughput X-ray topography measurement
JP2016170133A (en) * 2015-03-16 2016-09-23 株式会社東芝 Imaging apparatus and imaging method

Similar Documents

Publication Publication Date Title
US10101674B2 (en) Methods and apparatus for determining focus
TWI649628B (en) Differential methods and apparatus for metrology of semiconductor targets
KR101882892B1 (en) Method and apparatus for measuring a structure on a substrate, models for error correction, computer program products for implementing such methods &amp; apparatus
TWI641828B (en) Method of characterizing structures of interest on semiconductor wafer and semiconductor metrology system
US7352453B2 (en) Method for process optimization and control by comparison between 2 or more measured scatterometry signals
JP5016579B2 (en) Method for supporting selection of model freedom and fixed parameters, method for measuring characteristics, device manufacturing method, spectrometer and lithographic apparatus
US10634490B2 (en) Determining edge roughness parameters
JP6903131B2 (en) Methods and equipment for measuring parameters of lithographic processes, computer program products for implementing such methods and equipment
KR101331107B1 (en) Scatterometer and lithographic apparatus
JP2013522610A (en) Inspection for lithography
JP2010133941A (en) Measurement of diffracting structure, broadband, polarized, ellipsometry, and underlying structure
US20110020956A1 (en) Method of measuring pattern shape, method of manufacturing semiconductor device, and process control system
KR101114729B1 (en) High throughput across-wafer-variation mapping
JP2008139303A (en) Inspection method and apparatus, lithographic apparatus, lithographic processing cell, and device manufacturing method
KR20180095605A (en) Polarization tuning in scatterometry
JP2005315742A (en) Measuring apparatus and measuring method
TW201643405A (en) Optical metrology with reduced focus error sensitivity
KR20220038707A (en) Automatic recipe optimization for overlay metrology systems
KR102303571B1 (en) Target measuring method, measuring device, polarizer assembly
KR100431112B1 (en) Method and device for optically monitoring processes for manufacturing microstructured surfaces in the production of semiconductors
US7123414B2 (en) Method for producing library
KR20110110263A (en) Method of determining a characteristic
EP3467589A1 (en) Determining edge roughness parameters