JP6402440B2 - Inspection device - Google Patents

Inspection device Download PDF

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JP6402440B2
JP6402440B2 JP2013223114A JP2013223114A JP6402440B2 JP 6402440 B2 JP6402440 B2 JP 6402440B2 JP 2013223114 A JP2013223114 A JP 2013223114A JP 2013223114 A JP2013223114 A JP 2013223114A JP 6402440 B2 JP6402440 B2 JP 6402440B2
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optical system
inspection
defect
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photomask
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周矢 金子
周矢 金子
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Toppan Inc
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本発明は、遮光膜によるパターンを形成したフォトマスク上の欠陥を検出し、検出した欠陥の種類を判定する検査装置、ならびに検査方法に関する。   The present invention relates to an inspection apparatus and an inspection method for detecting a defect on a photomask having a pattern formed by a light shielding film and determining the type of the detected defect.

半導体集積回路を製造するためのリソグラフィ工程では、自動焦点機構等を用いて、回路パターン等の原画をウエハ上に位置決めし、縮小投影して露光しつつ、同じパターンを順次焼き付ける。その際、パターン原版であるフォトマスクのガラス基板上に異物や欠陥が存在すると、ウエハ上にそれらが転写され、回路の短絡障害等の原因になることがある。   In a lithography process for manufacturing a semiconductor integrated circuit, an autofocus mechanism or the like is used to position an original image such as a circuit pattern on a wafer, and the same pattern is sequentially printed while being reduced and projected. At this time, if foreign matter or defects are present on the glass substrate of the photomask which is the pattern original, they may be transferred onto the wafer, causing a short circuit failure or the like of the circuit.

フォトマスクの製造プロセスでは、ガラス基板のパターン形成面上に、クロム(Cr)等の金属の遮光膜をエッチング加工することにより配線などのパターンを形成した後、パターン形成面上に生じる欠陥の有無を検査装置にて判定する。この検査では、フォトマスクにレーザー光を投射し、透過光、反射光を検出することによりパターンの判定を行う。   In the photomask manufacturing process, after forming a pattern such as wiring by etching a light shielding film of a metal such as chromium (Cr) on the pattern formation surface of the glass substrate, the presence or absence of defects occurring on the pattern formation surface Is determined by the inspection device. In this inspection, pattern determination is performed by projecting laser light onto a photomask and detecting transmitted light and reflected light.

欠陥を検出した場合、洗浄や修正によって欠陥の除去が試みられる。欠陥の種類によって修正方法が異なり、異物に由来する欠陥を検出した場合、マスクの再洗浄やレーザー光の照射などによって欠陥を除去する。遮光膜に由来する欠陥を検出した場合、FIB(Focused Ion Beam)の照射やAFM(Atomic Force Microscope)の探針を用いた掘削などによって欠陥を除去する。   When a defect is detected, removal of the defect is attempted by cleaning or correction. The correction method differs depending on the type of defect, and when a defect derived from a foreign substance is detected, the defect is removed by re-cleaning the mask or irradiating laser light. When a defect derived from the light shielding film is detected, the defect is removed by irradiation with FIB (Focused Ion Beam) or excavation using an AFM (Atomic Force Microscope) probe.

しかし近年では、許容可能な欠陥サイズの微細化等の理由から異物による欠陥と遮光膜による欠陥の判別が困難である。とりわけ、パターンのエッジに欠陥を検出した場合、それが遮光膜の欠陥か、エッジに付着した異物か、を判別することができない。したがって、たいていの場合欠陥が検出された場合の次工程として、走査型電子顕微鏡(SEM:Scanning Electron Microscope)による欠陥撮影が行われる。しかしSEM撮影には欠陥の位置を示す座標データが必要となるため、欠陥撮影の際に座標の再入力が必要となる。また、検査装置からSEMへのマスクの搬送も必要となる。   However, in recent years, it is difficult to discriminate between a defect due to a foreign substance and a defect due to a light shielding film for reasons such as an allowable defect size miniaturization. In particular, when a defect is detected at the edge of the pattern, it cannot be determined whether the defect is a light shielding film or a foreign substance attached to the edge. Therefore, in most cases, as a next step when a defect is detected, a defect image is taken by a scanning electron microscope (SEM). However, since coordinate data indicating the position of a defect is required for SEM imaging, it is necessary to re-input coordinates at the time of defect imaging. Further, it is necessary to transport the mask from the inspection apparatus to the SEM.

特開2003−185592号公報JP 2003-185592 A 特開2008−166264号公報JP 2008-166264 A

本発明は、前記の問題点を鑑みてなされたものであって、その課題は、異物由来の欠陥と遮光膜由来の欠陥の判定を正確に且つ短時間で行って、歩留まりの低下や納期遅れ等の問題を解消することができる検査装置を提供することである。   The present invention has been made in view of the above-mentioned problems, and its problem is to accurately determine a defect derived from a foreign substance and a defect derived from a light-shielding film in a short time, thereby reducing yield and delaying delivery time. It is an object of the present invention to provide an inspection apparatus capable of solving such problems.

上記の課題を解決するための手段として、請求項1に記載の発明は、
フォトマスクの欠陥を検出する検査装置であって、必ず実施する光を用いた光学系に基づく検査手段と、前記の検査手段で欠陥が検出された時に実施する電子線を用いた光学系に基づく検査手段を備えてなり、
光を用いた光学系に基づく検査手段の光がレーザー光であり、電子線を用いた光学系に基づく検査手段が、SEM撮影の光学系に基づく検査手段であり、
レーザー光を用いた光学系に基づく検査手段では、レーザー光は対物レンズによって検査対象のフォトマスク上に集束し、検査対象のフォトマスクを反射した光はビームスプリッタによって方向を変えられ、反射光集光レンズによって反射光検出器に集光され結像し、一方、検査対象のフォトマスクを透過した光は透過光集光レンズによって透過光検出器に集光され結像し、これら検出した画像データを解析することで欠陥の有無を判定するものであり、
SEM撮影の光学系に基づく検査手段では、電子源より生成された一次電子線が、一次電子加速電極で加速され、コンデンサレンズで収束され、反射板の中心孔を通過し、走査コイルによって偏向走査されたのち、対物レンズによって検査対象のフォトマスク上に集束され、検査対象のフォトマスクから生成した二次電子は反射板に衝突し、それを二次電子検出器によって検出され、最終的に像として変換されるものであり、
レーザー光を用いた光学系に基づく検査手段による欠陥検査で欠陥があることを確認した場合、レーザー光を用いた光学系に基づく検査手段とSEM撮影の光学系に基づく検査手段が自動で切り替わる手段と、
レーザー光を用いた光学系に基づく検査手段が検出した欠陥の座標を、SEM撮影の光学系に基づく検査手段に伝達する手段と、
検査対象のフォトマスクを、SEM撮影の光学系に基づく検査手段に移送する手段と、
SEM撮影の光学系に基づく検査手段が検出した欠陥の画像を取得し記憶する手段と、
取得した欠陥情報を、欠陥の画像と共に表示する手段と、
欠陥の画像データの画像処理を行い、欠陥の種類を判定するための演算処理および基準データなどとの比較演算などの処理を行う手段を備えていることを特徴とする検査装置である。
As means for solving the above problems, the invention according to claim 1
An inspection apparatus for detecting a defect in a photomask, which is based on an inspection system based on an optical system that always uses light, and an optical system that uses an electron beam when a defect is detected by the inspection means With inspection means,
The light of the inspection means based on the optical system using light is laser light, the inspection means based on the optical system using electron beam is the inspection means based on the optical system of SEM photography,
In the inspection means based on the optical system using laser light, the laser light is focused on the photomask to be inspected by the objective lens, and the light reflected from the photomask to be inspected is changed in direction by the beam splitter, and the reflected light is collected. On the other hand, the light that has been focused on the reflected light detector by the optical lens and imaged, while the light that has passed through the photomask to be inspected is focused on the transmitted light detector by the transmitted light condensing lens and imaged. Is used to determine the presence or absence of defects,
In the inspection means based on the optical system for SEM imaging, the primary electron beam generated from the electron source is accelerated by the primary electron acceleration electrode, converged by the condenser lens, passes through the central hole of the reflector, and is deflected and scanned by the scanning coil. After that, it is focused on the photomask to be inspected by the objective lens, and the secondary electrons generated from the photomask to be inspected collide with the reflector, which is detected by the secondary electron detector and finally the image. Is converted as
A means for automatically switching between an inspection means based on an optical system using laser light and an inspection means based on an optical system for SEM imaging when it is confirmed that there is a defect by an inspection means based on the inspection means based on an optical system using laser light. When,
Means for transmitting coordinates of a defect detected by an inspection unit based on an optical system using laser light to an inspection unit based on an optical system for SEM imaging;
Means for transferring a photomask to be inspected to inspection means based on an optical system for SEM imaging;
Means for acquiring and storing an image of a defect detected by an inspection means based on an optical system of SEM photography;
Means for displaying the acquired defect information together with an image of the defect ;
An inspection apparatus comprising: means for performing image processing of defect image data and performing processing such as calculation processing for determining the type of defect and comparison calculation with reference data and the like.

本発明により、一連の欠陥検査によって欠陥の有無が判別できるだけでなく、欠陥を検出した場合に、同時に欠陥の種類も判別でき、欠陥のSEM撮影を別途実施することなく、修正方法を決定することができる。   According to the present invention, not only the presence / absence of a defect can be determined by a series of defect inspections, but also when a defect is detected, the type of defect can also be determined at the same time, and a correction method can be determined without separately performing SEM imaging of the defect. Can do.

本発明に係る検査装置の構造の一例を説明する模式図である。It is a schematic diagram explaining an example of the structure of the inspection apparatus which concerns on this invention. 本発明に係る検査装置を用いた場合の欠陥検査方法の一例を説明するフロー図である。It is a flowchart explaining an example of the defect inspection method at the time of using the inspection apparatus which concerns on this invention.

以下、本発明に係る一実施形態ついて図1、図2を用いて説明する。
図1は本発明の請求項1に係る検査装置の概略図である。装置は欠陥検査のレーザー光などの光を用いた光学系に基づく検査手段1とSEMなどの電子線を用いた光学系に基づく検査手段9の2つが存在する。以下、電子線を用いた光学系に基づく検査手段9としてSEMを例にとって説明するが、これに限定するものではない。
An embodiment according to the present invention will be described below with reference to FIGS.
FIG. 1 is a schematic view of an inspection apparatus according to claim 1 of the present invention. There are two apparatuses, an inspection means 1 based on an optical system using light such as laser light for defect inspection and an inspection means 9 based on an optical system using an electron beam such as SEM. Hereinafter, although the SEM will be described as an example of the inspection means 9 based on an optical system using an electron beam, the invention is not limited to this.

光を用いた光学系に基づく検査手段1は、光源2と、反射光検出器6と、透過光検出器8と、光源2、検査対象のフォトマスク18、および前記の両検出器の間に基準光の光路及び照射光の光路を形成する反射光集光レンズ5や透過光集光レンズ7などの光学素子群を備えている一般的なものである。光源2にはレーザー光などが用いられる。また、光学系の中に音響光学的光線スキャナも備えられており、これによって光を偏向させることが可能となる。レーザー光は最終的に対物レンズ4によって検査対象のフォトマスク18上に集束する。検査対象のフォトマスク18を反射した光はビームスプリッタ3によって方向を変えられ、反射光集光レンズ5によって反射光検出器6に集光され結像する。一方、検査対象のフォトマスク18を透過した光は透過光集光レンズ7によって透過光検出器8に集光され結像する。これら検出した画像データを解析することで欠陥の有無を判定する。これらすべてのパーツは、SEM撮影時には移動し、撮影の邪魔にならないよう格納される。   An inspection means 1 based on an optical system using light includes a light source 2, a reflected light detector 6, a transmitted light detector 8, a light source 2, a photomask 18 to be inspected, and both detectors. It is a general one provided with a group of optical elements such as a reflected light condensing lens 5 and a transmitted light condensing lens 7 that form an optical path of reference light and an optical path of irradiation light. Laser light or the like is used for the light source 2. In addition, an acousto-optic beam scanner is also provided in the optical system, which makes it possible to deflect the light. The laser beam is finally focused on the photomask 18 to be inspected by the objective lens 4. The light reflected from the photomask 18 to be inspected is changed in direction by the beam splitter 3 and condensed on the reflected light detector 6 by the reflected light collecting lens 5 to form an image. On the other hand, the light transmitted through the photomask 18 to be inspected is condensed on the transmitted light detector 8 by the transmitted light condensing lens 7 to form an image. The presence or absence of a defect is determined by analyzing the detected image data. All these parts move during SEM photography and are stored so as not to interfere with photography.

電子線を用いた光学系に基づく検査手段9は、電子源10、一次電子加速電極11、コンデンサレンズ12、反射板13、走査コイル14、対物レンズ15、及び、二次電子検出器16を有する一般的なものである。SEM撮影時は、電子源10より一次電子線が生
成され、一次電子加速電極11で加速し、コンデンサレンズ12で収束され、反射板13の中心孔を通過し、走査コイル14によって偏向走査されたのち、対物レンズ15によって検査対象のフォトマスク18上に集束される。検査対象のフォトマスク18から生成した二次電子は反射板13に衝突し、それを二次電子検出器16によって検出され、最終的に像として変換される。欠陥検査時のパーツはすべて格納されるため、SEM撮影の原理自体は一般的なものと変わらない。
The inspection means 9 based on an optical system using an electron beam has an electron source 10, a primary electron acceleration electrode 11, a condenser lens 12, a reflector 13, a scanning coil 14, an objective lens 15, and a secondary electron detector 16. It is general. During SEM imaging, a primary electron beam is generated from the electron source 10, accelerated by the primary electron acceleration electrode 11, converged by the condenser lens 12, passed through the central hole of the reflector 13, and deflected and scanned by the scanning coil 14. Thereafter, the light is focused on the photomask 18 to be inspected by the objective lens 15. The secondary electrons generated from the photomask 18 to be inspected collide with the reflector 13 and are detected by the secondary electron detector 16 and finally converted into an image. Since all parts at the time of defect inspection are stored, the principle of SEM imaging itself is not different from a general one.

また、図1に示す検査装置は、光を用いた光学系に基づく検査手段1による欠陥検査で欠陥があることを確認した場合、自動的に検査手段が電子線を用いた光学系に基づく検査手段9へと切り替わると同時に、光を用いた光学系に基づく検査手段1が、検出した欠陥の座標を読み取り、記憶し、電子線を用いた光学系に基づく検査手段9に送ることによって、電子線を用いた光学系に基づく検査手段9は撮影箇所を決定することができる。以上のことを実施可能とするため、本発明の検査装置19は光を用いた光学系に基づく検査手段1において、検査対象のフォトマスク18を検査した結果、欠陥を検出した場合には、検査対象のフォトマスク18を、電子線を用いた光学系に基づく検査手段9に移送し、安定して検査できるように固定する手段を備えている。   In addition, when the inspection apparatus shown in FIG. 1 confirms that there is a defect in the defect inspection by the inspection means 1 based on the optical system using light, the inspection means automatically inspects based on the optical system using the electron beam. At the same time as switching to the means 9, the inspection means 1 based on the optical system using light reads the coordinates of the detected defect, stores them, and sends them to the inspection means 9 based on the optical system using an electron beam. The inspection means 9 based on the optical system using the line can determine the photographing location. In order to make it possible to carry out the above, the inspection apparatus 19 of the present invention is inspected when the inspection means 1 based on the optical system using light inspects the photomask 18 to be inspected and detects a defect. Means is provided for transferring the target photomask 18 to the inspection means 9 based on an optical system using an electron beam and fixing it so that it can be inspected stably.

加えて、電子線を用いた光学系に基づく検査手段9がSEM撮影後は、検査装置19の表示装置上に欠陥情報が自動的に表示されると同時に、撮影したSEM画像も併せて表示される。また本発明の検査装置19は、電子線を用いた光学系に基づく検査手段9がSEM撮影すると、その画像データを取得し記憶して、必要に応じて容易に取り出し、表示装置に表示することが可能である。また画像データの画像処理を行い、欠陥の種類を判定するための演算処理および基準データなどとの比較演算などの処理を行うことも可能である。 In addition, after the SEM imaging by the inspection means 9 based on an optical system using an electron beam, defect information is automatically displayed on the display device of the inspection device 19, and at the same time, the captured SEM image is also displayed. that. Inspecting apparatus 19 of the present invention were or are the inspection means 9 based on the optical system using an electron beam is SEM photographing, and obtains storing the image data, easily taken out if necessary, and displays it on the display device It is possible. It is also possible to perform image processing of the image data and perform processing such as calculation processing for determining the type of defect and comparison calculation with reference data.

図2は本発明に係る図1に示した検査装置を用いた場合の欠陥検査方法を説明するフロー図である。まず、ステップS101で検査対象のフォトマスク18を、光を用いた光学系に基づく検査手段1にロードし、ステップS102で検査条件を設定し、ステップS103で検査を開始する。検査が終了したらステップS104で欠陥の有無を確認する。欠陥がない場合、ステップS109で検査対象のフォトマスク18をアンロードする。欠陥がある場合、ステップS105で検査装置19が認識して自動的に、光を用いた光学系に基づく検査手段1から電子線を用いた光学系に基づく検査手段9に切り替わり、ステップS106で検出した欠陥座標に則って、欠陥の撮影が開始される。欠陥の撮影が終了すると、ステップS107で各欠陥情報が、撮影したSEM画像とともに本発明の検査装置19の表示装置に表示される。ステップS108で与えられた情報を元に、各欠陥に対して修正方法を決定したら、ステップS109で検査対象のフォトマスクをアンロードする。その後、修正を実施することが可能である。修正方法を決定する方法としては、人がSEM画像を見て、それらの特徴から、その欠陥が異物由来のものか、遮光膜由来のものか、を判定する。また、それらの画像の特徴と判定の正しい結果を予めコンピュータシステムの中にデジタルデータとして記憶し蓄積しておくことで、個々に観察されたSEM画像から欠陥が異物由来のものか、遮光膜由来のものか、を自動的に判定することも可能である。   FIG. 2 is a flowchart for explaining a defect inspection method when the inspection apparatus shown in FIG. 1 according to the present invention is used. First, the photomask 18 to be inspected is loaded into the inspection means 1 based on an optical system using light in step S101, inspection conditions are set in step S102, and inspection is started in step S103. When the inspection is completed, the presence or absence of a defect is confirmed in step S104. If there is no defect, the photomask 18 to be inspected is unloaded in step S109. If there is a defect, the inspection device 19 recognizes in step S105 and automatically switches from the inspection unit 1 based on the optical system using light to the inspection unit 9 based on the optical system using electron beam, and detected in step S106. In accordance with the defect coordinates, defect imaging is started. When the imaging of the defect is completed, each defect information is displayed on the display device of the inspection apparatus 19 of the present invention together with the captured SEM image in step S107. When the correction method for each defect is determined based on the information given in step S108, the inspection target photomask is unloaded in step S109. Thereafter, corrections can be made. As a method for determining the correction method, a person looks at the SEM image and determines from the characteristics whether the defect is derived from a foreign substance or a light shielding film. Also, by storing and accumulating the image characteristics and correct results as digital data in the computer system in advance, it is possible to determine whether the defects are derived from foreign matter or from the light shielding film from the individually observed SEM images. It is also possible to automatically determine whether or not the

本発明の検査装置19によって、欠陥の撮影を別途実施することなく、欠陥の有無の確認および修正方法の決定が達成される。本発明は上述に限定されるものではなく、特許請求の範囲に記載された発明の範囲にて様々な変更が可能である。   By the inspection apparatus 19 of the present invention, the presence / absence of a defect and determination of a correction method can be achieved without separately performing defect imaging. The present invention is not limited to the above, and various modifications can be made within the scope of the invention described in the claims.

(実施例1)
フォトマスクのテスト品(検査対象のフォトマスク)に対し、本発明に係る検査装置による欠陥検査を実施した。具体的には、まず、線幅が1:1のラインとスペースからなるパターンが描かれた8つのダイからなるフォトマスクのテスト品を作製した。
Example 1
Photomask test products to (photomask to be inspected), it was carried out defect inspection by the inspection apparatus according to the present onset bright. Specifically, first, a test product of a photomask composed of eight dies on which a pattern composed of lines and spaces having a line width of 1: 1 was drawn was produced.

次いで、そのテスト品を前記の検査装置にロードし、ダイ同士の透過・反射同時検査の検査条件の設定を実施し、検査を実行した。検査の結果、実欠陥を合計11個検出したため、光を用いた光学系に基づく検査手段が電子線を用いた光学系に基づく検査手段、具体的にはSEM(走査型電子顕微鏡)に自動的に切り替わり、欠陥検出箇所の11箇所においてSEM撮影が実行された。   Next, the test product was loaded into the inspection apparatus, the inspection conditions for simultaneous transmission / reflection inspection between dies were set, and the inspection was performed. As a result of the inspection, a total of 11 actual defects were detected, so that the inspection means based on the optical system using light is automatically applied to the inspection means based on the optical system using an electron beam, specifically SEM (scanning electron microscope). The SEM imaging was executed at 11 defect detection locations.

SEM撮影終了後、本発明の検査装置の表示装置上に、検出した11個の欠陥の情報と併せて撮影したSEM画像が表示された。装置操作者は表示された11個の欠陥の分類を実施した。SEM画像も併せて表示されることによって、ガラス上の遮光膜異物が1個、遮光膜のカケ欠陥が3個、遮光膜上の異物が3個、パターンの形状不良が3箇所、遮光膜の大きなクズレが1個あることを確認できた。装置操作者はガラス上の遮光膜異物にレーザー光の投射による修正、クズレにはFIBによる修正が必要との判断を下し、検査したテスト品の検査対象のフォトマスクをアンロードした。   After completion of SEM imaging, an SEM image captured along with information on the detected 11 defects was displayed on the display device of the inspection apparatus of the present invention. The machine operator performed a classification of the 11 defects displayed. The SEM image is also displayed, so that one foreign substance on the light shielding film on the glass, three defects on the light shielding film, three foreign substances on the light shielding film, three pattern shape defects, It was confirmed that there was one large scum. The operator of the apparatus determined that the light shielding film on the glass had to be corrected by projecting a laser beam, and that the scratch was corrected by FIB, and unloaded the photomask to be inspected of the inspected test product.

装置操作者は検査を開始してから、表示装置上に欠陥情報が表示されるまで、検査装置に対する操作は不要であった。すなわち、別途SEM撮影の必要がなく、欠陥の座標の再入力や検査対象のフォトマスク18の搬送の必要がなかった。   The apparatus operator does not need to operate the inspection apparatus until the defect information is displayed on the display apparatus after starting the inspection. That is, there is no need for separate SEM imaging, and there is no need for re-input of defect coordinates or transport of the inspection target photomask 18.

(比較例1)
前記の実施例1に対し、同様のテスト品において欠陥検査とSEM撮影を別々の装置で行った。具体的には、まず、KLA−Tencor(株)社製の検査装置にテスト品をロードし、実施例1と同じ条件でダイ同士の透過・反射同時検査を実施した。検査終了後、11個の欠陥の情報が表示装置上に表示された。装置操作者は欠陥の内の一つであるラインとラインの間に検出した欠陥に対して、欠陥情報だけではガラス上の遮光膜異物か、それとも遮光膜の突起欠陥か判断できなかったため、修正方法の決定には至らなかった。装置操作者はテスト品をアンロードし、欠陥情報をプリントアウトし、Advantest(株)社製のSEMへテスト品を搬送した。
(Comparative Example 1)
For the same test product as in Example 1, defect inspection and SEM imaging were performed with separate apparatuses. Specifically, first, a test product was loaded into an inspection apparatus manufactured by KLA-Tencor Co., Ltd., and simultaneous transmission / reflection inspection between dies was performed under the same conditions as in Example 1. After the inspection was completed, information on 11 defects was displayed on the display device. The operator cannot correct a defect detected between lines, which is one of the defects, because the defect information alone cannot determine whether it is a light shielding film foreign object on glass or a protrusion defect on the light shielding film. The method was not decided. The operator of the apparatus unloaded the test product, printed out the defect information, and transported the test product to the SEM manufactured by Advantest.

テスト品をSEMにロードし、プリントアウトした欠陥情報をもとに、欠陥座標を入力し、撮影条件を設定した。SEM撮影を実行し、撮影後のSEM画像を表示装置上で確認した。その結果、実施例1と同様に11個の欠陥の分類が可能になり、ガラス上の遮光膜異物にレーザー光の投射による修正、クズレにはFIBによる修正が必要との判断を下し、テスト品をアンロードした。   A test product was loaded into the SEM, and based on the printed defect information, defect coordinates were input and imaging conditions were set. SEM imaging was performed, and the SEM image after imaging was confirmed on the display device. As a result, 11 defects can be classified as in Example 1, and it was determined that correction by projection of laser light on the light-shielding film foreign material on the glass and that correction by FIB was necessary for scratches. The item was unloaded.

装置操作者は実施例1と比較し、テスト品の搬送や座標の再入力の手間が必要となった。また、実施例1の場合、検査終了からSEM撮影開始まで約3分であったのに対し、比較例1では、10分以上の時間を要し、時間の浪費にも繋がった。以上より、比較例1は本発明の効果を実証する結果となった。   Compared with Example 1, the operator of the apparatus needed to carry the test product and re-input the coordinates. Further, in the case of Example 1, it took about 3 minutes from the end of the inspection to the start of SEM imaging, but in Comparative Example 1, it took 10 minutes or more, leading to wasted time. From the above, Comparative Example 1 proved the effect of the present invention.

本発明は、半導体集積回路を形成するフォトマスクの製造・管理工程で好適に利用できる。   INDUSTRIAL APPLICABILITY The present invention can be suitably used in photomask manufacturing / management processes for forming semiconductor integrated circuits.

1…光を用いた光学系に基づく検査手段、2…光源、3…ビームスプリッタ、4…対物レンズ、5…反射光集光レンズ、6…反射光検出器、7…透過光集光レンズ、8…透過光検出器、9…電子線を用いた光学系に基づく検査手段、10…電子源、11…一次電子加速電極、12…コンデンサレンズ、13…反射板、14…走査コイル、15…対物レンズ、16…二次電子検出器、17…ステージ、18…検査対象のフォトマスク、19…検査装置   DESCRIPTION OF SYMBOLS 1 ... Inspection means based on optical system using light, 2 ... Light source, 3 ... Beam splitter, 4 ... Objective lens, 5 ... Reflected light condensing lens, 6 ... Reflected light detector, 7 ... Transmitted light condensing lens, DESCRIPTION OF SYMBOLS 8 ... Transmitted light detector, 9 ... Inspection means based on optical system using electron beam, 10 ... Electron source, 11 ... Primary electron acceleration electrode, 12 ... Condenser lens, 13 ... Reflector, 14 ... Scanning coil, 15 ... Objective lens, 16 ... secondary electron detector, 17 ... stage, 18 ... photomask to be inspected, 19 ... inspection device

Claims (1)

フォトマスクの欠陥を検出する検査装置であって、必ず実施する光を用いた光学系に基づく検査手段と、前記の検査手段で欠陥が検出された時に実施する電子線を用いた光学系に基づく検査手段を備えてなり、
光を用いた光学系に基づく検査手段の光がレーザー光であり、電子線を用いた光学系に基づく検査手段が、SEM撮影の光学系に基づく検査手段であり、
レーザー光を用いた光学系に基づく検査手段では、レーザー光は対物レンズによって検査対象のフォトマスク上に集束し、検査対象のフォトマスクを反射した光はビームスプリッタによって方向を変えられ、反射光集光レンズによって反射光検出器に集光され結像し、一方、検査対象のフォトマスクを透過した光は透過光集光レンズによって透過光検出器に集光され結像し、これら検出した画像データを解析することで欠陥の有無を判定するものであり、
SEM撮影の光学系に基づく検査手段では、電子源より生成された一次電子線が、一次電子加速電極で加速され、コンデンサレンズで収束され、反射板の中心孔を通過し、走査コイルによって偏向走査されたのち、対物レンズによって検査対象のフォトマスク上に集束され、検査対象のフォトマスクから生成した二次電子は反射板に衝突し、それを二次電子検出器によって検出され、最終的に像として変換されるものであり、
レーザー光を用いた光学系に基づく検査手段による欠陥検査で欠陥があることを確認した場合、レーザー光を用いた光学系に基づく検査手段とSEM撮影の光学系に基づく検査手段が自動で切り替わる手段と、
レーザー光を用いた光学系に基づく検査手段が検出した欠陥の座標を、SEM撮影の光学系に基づく検査手段に伝達する手段と、
検査対象のフォトマスクを、SEM撮影の光学系に基づく検査手段に移送する手段と、
SEM撮影の光学系に基づく検査手段が検出した欠陥の画像を取得し記憶する手段と、
取得した欠陥情報を、欠陥の画像と共に表示する手段と、
欠陥の画像データの画像処理を行い、欠陥の種類を判定するための演算処理および基準データなどとの比較演算などの処理を行う手段を備えていることを特徴とする検査装置。
An inspection apparatus for detecting a defect in a photomask, which is based on an inspection system based on an optical system that always uses light, and an optical system that uses an electron beam when a defect is detected by the inspection means With inspection means,
The light of the inspection means based on the optical system using light is laser light, the inspection means based on the optical system using electron beam is the inspection means based on the optical system of SEM photography,
In the inspection means based on the optical system using laser light, the laser light is focused on the photomask to be inspected by the objective lens, and the light reflected from the photomask to be inspected is changed in direction by the beam splitter, and the reflected light is collected. On the other hand, the light that has been focused on the reflected light detector by the optical lens and imaged, while the light that has passed through the photomask to be inspected is focused on the transmitted light detector by the transmitted light condensing lens and imaged. Is used to determine the presence or absence of defects,
In the inspection means based on the optical system for SEM imaging, the primary electron beam generated from the electron source is accelerated by the primary electron acceleration electrode, converged by the condenser lens, passes through the central hole of the reflector, and is deflected and scanned by the scanning coil. After that, it is focused on the photomask to be inspected by the objective lens, and the secondary electrons generated from the photomask to be inspected collide with the reflector, which is detected by the secondary electron detector and finally the image. Is converted as
A means for automatically switching between an inspection means based on an optical system using laser light and an inspection means based on an optical system for SEM imaging when it is confirmed that there is a defect by an inspection means based on the inspection means based on an optical system using laser light. When,
Means for transmitting coordinates of a defect detected by an inspection unit based on an optical system using laser light to an inspection unit based on an optical system for SEM imaging;
Means for transferring a photomask to be inspected to inspection means based on an optical system for SEM imaging;
Means for acquiring and storing an image of a defect detected by an inspection means based on an optical system of SEM photography;
Means for displaying the acquired defect information together with an image of the defect ;
An inspection apparatus, comprising: means for performing image processing of defect image data and performing processing such as calculation processing for determining the type of defect and comparison calculation with reference data and the like .
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JPS58162038A (en) * 1982-03-23 1983-09-26 Canon Inc Pattern defect detection apparatus
JPS60218845A (en) * 1984-04-16 1985-11-01 Hitachi Ltd Apparatus for testing foreign matter
JPS61267246A (en) * 1985-05-21 1986-11-26 Hitachi Ltd Foreign matter detector
JPS6313342A (en) * 1986-07-04 1988-01-20 Hitachi Ltd Fine foreign material inspecting device
JP3167642B2 (en) * 1991-09-25 2001-05-21 株式会社クボタ Rice transplanter seedling planting equipment
JPH11125602A (en) * 1996-07-01 1999-05-11 Advantest Corp Method and device for analyzing foreign matter
US6407373B1 (en) * 1999-06-15 2002-06-18 Applied Materials, Inc. Apparatus and method for reviewing defects on an object
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JP2003185592A (en) * 2001-12-21 2003-07-03 Sony Corp Flaw determination method
US7355709B1 (en) * 2004-02-23 2008-04-08 Kla-Tencor Technologies Corp. Methods and systems for optical and non-optical measurements of a substrate
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