JP2006308460A

JP2006308460A - Apparatus and method for inspecting substrate and method for manufacturing semiconductor device

Info

Publication number: JP2006308460A
Application number: JP2005132318A
Authority: JP
Inventors: Ichirota Nagahama; 濱一郎太長; Yuichiro Yamazaki; 崎裕一郎山; Atsushi Onishi; 西篤志大
Original assignee: Toshiba Corp
Current assignee: Toshiba Corp
Priority date: 2005-04-28
Filing date: 2005-04-28
Publication date: 2006-11-09

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus and a method for inspecting a substrate, capable of highly sensitively detecting a defect of the substrate, and to provide a method for manufacturing a semiconductor device, which is excellent in yield. <P>SOLUTION: In the apparatus for inspecting the substrate, a movable aperture plate 81 having a plurality of apertures whose shapes and sizes correspond to portions of an object to be inspected, is disposed at a focal plane of a secondary electron beam, and apertures 81Bα-81Bγ, 81Dα-81Dγ are selected such that the secondary electron beam which is emitted from an arbitrary portion of the object to be inspected at a high secondary-emission coefficient, passes through the movable aperture plate 81 and provides an image on a detection surface of an MCP detector 31. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、基板検査装置、基板検査方法および半導体装置の製造方法に関し、例えば電子ビームを用いた半導体パターン等の観察および検査を対象とする。 The present invention relates to a substrate inspection apparatus, a substrate inspection method, and a semiconductor device manufacturing method, and is intended for observation and inspection of a semiconductor pattern using an electron beam, for example.

半導体パターンの欠陥検査のために電子ビームが利用されている。例えば特許文献１には、矩形状の電子ビームを電子照射手段にて形成して一次電子ビームとして試料に照射し、その試料表面の形状／材質／電位の変化に応じて発生した二次電子、反射電子および後方散乱電子である二次電子ビームを写像投影光学手段にて電子検出部に拡大投影し、試料表面画像を得る手法が開示されている。さらに、この手法に加えて一次電子ビームを電子ビーム偏向手段であるウィーンフィルタにて偏向させ、試料表面に対して垂直に入射させ、なおかつ二次電子ビームを同一のウィーンフィルタ内を直進させて写像投影光学系に導入する方法も提案されている（例えば特許文献２）。 An electron beam is used for defect inspection of semiconductor patterns. For example, in Patent Document 1, a rectangular electron beam is formed by an electron irradiation means, a sample is irradiated as a primary electron beam, and secondary electrons generated according to changes in the shape / material / potential of the sample surface, There is disclosed a method of obtaining a sample surface image by enlarging and projecting a secondary electron beam, which is a reflected electron and a backscattered electron, onto an electron detection unit by mapping projection optical means. Furthermore, in addition to this method, the primary electron beam is deflected by a Wien filter which is an electron beam deflecting means, is incident perpendicularly to the sample surface, and the secondary electron beam travels straight through the same Wien filter and is mapped. A method of introducing it into the projection optical system has also been proposed (for example, Patent Document 2).

しかしながら、例えば特許文献２に記載の装置では、検出系にて収集される二次電子、反射電子および後方散乱電子の放出角度範囲（垂直方向を基準とする）−θb〜＋θbが、二次電子ビーム焦点面に配設されている円孔形状の開き角絞りによって一律に制限されていた。そのため、得られる二次電子像においては、ＳＥＭ（Scanning Electron Microscope）方式の欠陥検査装置で得られる二次電子像に比べ、エッジ部でのコントラストが低く、また、側壁部の明度も劣っていた。このため、正確な形状認識ができず、パターン欠陥検出感度の低下を招く等の問題があった。
特開平７−２４９３９３号公報特開平１１−１３２９７５号公報 However, in the apparatus described in Patent Document 2, for example, the emission angle range (with respect to the vertical direction) −θb to + θb of secondary electrons, reflected electrons, and backscattered electrons collected by the detection system is secondary electrons. It was uniformly limited by a circular aperture-shaped aperture stop arranged in the beam focal plane. Therefore, in the obtained secondary electron image, the contrast at the edge portion is low and the brightness of the side wall portion is also inferior compared to the secondary electron image obtained by the SEM (Scanning Electron Microscope) type defect inspection apparatus. . For this reason, there was a problem that accurate shape recognition could not be performed, leading to a decrease in pattern defect detection sensitivity.
JP 7-249393 A Japanese Patent Laid-Open No. 11-132975

本発明の目的は、基板の欠陥を高感度で検出することができる基板検査装置および基板検査方法、並びに歩留まりに優れた半導体装置の製造方法を提供することにある。 An object of the present invention is to provide a substrate inspection apparatus and a substrate inspection method capable of detecting a substrate defect with high sensitivity, and a method for manufacturing a semiconductor device excellent in yield.

本発明は、以下の手段により上記課題の解決を図る。 The present invention aims to solve the above problems by the following means.

即ち、本発明によれば、
電子ビームを生成して試料である基板に一次電子ビームとして照射する工程と、
前記一次電子ビームの照射を受けて前記基板から放出される二次電子、反射電子および後方散乱電子の少なくともいずれかを導いて二次電子ビームとして拡大投影し、結像させる写像投影工程と、
結像した前記二次電子ビームを検出して前記基板の状態を表す画像信号を出力する工程と、
を備える基板検査方法であって、
前記写像投影工程は、
前記二次電子、前記反射電子および前記後方散乱電子の少なくともいずれかの放出方向と前記二次電子ビームの光軸との角度を光軸基準放出角度と定義すると、任意の検査対象部位の画像信号の量が他の部位の画像信号の量よりも増大するように、前記検査対象部位の幾何学的形状に応じた光軸基準放出角度を有する前記二次電子、前記反射電子および前記後方散乱電子の少なくともいずれかを選択的に結像させる工程を含む、
基板検査方法が提供される。 That is, according to the present invention,
A step of generating an electron beam and irradiating the sample substrate as a primary electron beam;
A mapping projecting step in which at least one of secondary electrons, reflected electrons, and backscattered electrons emitted from the substrate in response to irradiation of the primary electron beam is led to be enlarged and projected as a secondary electron beam, and imaged;
Detecting the imaged secondary electron beam and outputting an image signal representing the state of the substrate;
A substrate inspection method comprising:
The mapping projection step includes:
When an angle between an emission direction of at least one of the secondary electrons, the reflected electrons, and the backscattered electrons and an optical axis of the secondary electron beam is defined as an optical axis reference emission angle, an image signal of an arbitrary inspection target site The secondary electrons, the backscattered electrons, and the backscattered electrons having an optical axis reference emission angle corresponding to the geometric shape of the region to be inspected so that the amount of image signals is larger than the amount of image signals of other regions. Selectively imaging at least one of
A substrate inspection method is provided.

また、本発明によれば、
電子ビームを生成して試料である基板に一次電子ビームとして照射する工程と、
前記一次電子ビームの照射を受けて前記基板から放出される二次電子、反射電子および後方散乱電子の少なくともいずれかを導いて二次電子ビームとして拡大投影し、結像させる写像投影工程と、
結像した前記二次電子ビームを検出して前記基板の状態を表す画像信号を出力する工程と、
を備える基板検査方法であって、
前記写像投影工程は、
前記二次電子、前記反射電子および前記後方散乱電子の少なくともいずれかの放出方向と前記二次電子ビームの光軸との角度を光軸基準放出角度と定義すると、任意の検査対象部位とこれに隣接する部位との画像コントラストが高くなるように、前記検査対象部位の幾何学的形状に応じた光軸基準放出角度を有する前記二次電子、前記反射電子および前記後方散乱電子の少なくともいずれかを選択的に結像させる工程を含む、
基板検査方法が提供される。 Moreover, according to the present invention,
A step of generating an electron beam and irradiating the sample substrate as a primary electron beam;
A mapping projecting step in which at least one of secondary electrons, reflected electrons, and backscattered electrons emitted from the substrate in response to irradiation of the primary electron beam is led to be enlarged and projected as a secondary electron beam, and imaged;
Detecting the imaged secondary electron beam and outputting an image signal representing the state of the substrate;
A substrate inspection method comprising:
The mapping projection step includes:
When the angle between the emission direction of at least one of the secondary electrons, the reflected electrons, and the backscattered electrons and the optical axis of the secondary electron beam is defined as an optical axis reference emission angle, an arbitrary inspection target site and At least one of the secondary electrons, the reflected electrons, and the backscattered electrons having an optical axis reference emission angle corresponding to the geometric shape of the inspection target part so that an image contrast with an adjacent part is high. Including selectively imaging.
A substrate inspection method is provided.

また、本発明によれば、
電子ビームを生成して試料である基板に一次電子ビームとして照射する一次ビーム照射手段と、
前記一次電子ビームの照射を受けて前記基板から放出される二次電子、反射電子および後方散乱電子の少なくともいずれかを導いて二次電子ビームとして拡大投影して結像させる写像投影手段と、
前記二次電子ビームが結像する検出面を有し、前記検出面で前記二次電子ビームを検出して前記基板の状態を表す画像信号を出力する電子ビーム検出手段と、
前記二次電子、前記反射電子および前記後方散乱電子の少なくともいずれかの放出方向と前記二次電子ビームの光軸との角度を光軸基準放出角度と定義すると、任意の検査対象部位の画像信号の量が他の部位の画像信号の量よりも増大するように、前記検査対象部位の幾何学的形状に応じた光軸基準放出角度を有する前記二次電子、前記反射電子および前記後方散乱電子の少なくともいずれかを選択的に前記電子ビーム検出手段の前記検出面に結像させる電子選択手段と、
を備える基板検査装置が提供される。 Moreover, according to the present invention,
A primary beam irradiation means for generating an electron beam and irradiating the sample substrate as a primary electron beam;
Mapping projection means for directing at least one of secondary electrons, reflected electrons, and backscattered electrons emitted from the substrate upon irradiation of the primary electron beam and projecting it as a secondary electron beam to form an image;
An electron beam detector that has a detection surface on which the secondary electron beam forms an image, detects the secondary electron beam on the detection surface, and outputs an image signal representing the state of the substrate;
When an angle between an emission direction of at least one of the secondary electrons, the reflected electrons, and the backscattered electrons and an optical axis of the secondary electron beam is defined as an optical axis reference emission angle, an image signal of an arbitrary inspection target site The secondary electrons, the backscattered electrons, and the backscattered electrons having an optical axis reference emission angle corresponding to the geometric shape of the region to be inspected so that the amount of image signals is larger than the amount of image signals of other regions. Electron selection means for selectively imaging at least one of the above onto the detection surface of the electron beam detection means,
A substrate inspection apparatus is provided.

さらに、本発明によれば、
電子ビームを生成して試料である基板に一次電子ビームとして照射する一次電子ビーム照射手段と、
前記一次電子ビームの照射を受けて前記基板から放出される二次電子、反射電子および後方散乱電子の少なくともいずれかを導いて二次電子ビームとして拡大投影して結像させる写像投影手段と、
前記二次電子ビームが結像する検出面を有し、前記検出面で前記二次電子ビームを検出して前記基板の状態を表す画像信号を出力する電子ビーム検出手段と、
前記二次電子、前記反射電子および前記後方散乱電子の少なくともいずれかの放出方向と前記二次電子ビームの光軸との角度を光軸基準放出角度と定義すると、任意の検査対象部位とこれに隣接する部位との画像コントラストが高くなるように、前記検査対象部位の幾何学的形状に応じた光軸基準放出角度を有する前記二次電子、前記反射電子および前記後方散乱電子の少なくともいずれかを選択的に前記電子ビーム検出手段の前記検出面に結像させる電子選択手段と、
を備える基板検査装置が提供される。 Furthermore, according to the present invention,
A primary electron beam irradiation means for generating an electron beam and irradiating the substrate as a sample as a primary electron beam;
Mapping projection means for directing at least one of secondary electrons, reflected electrons, and backscattered electrons emitted from the substrate upon irradiation of the primary electron beam and projecting it as a secondary electron beam to form an image;
An electron beam detector that has a detection surface on which the secondary electron beam forms an image, detects the secondary electron beam on the detection surface, and outputs an image signal representing the state of the substrate;
When the angle between the emission direction of at least one of the secondary electrons, the reflected electrons, and the backscattered electrons and the optical axis of the secondary electron beam is defined as an optical axis reference emission angle, an arbitrary inspection target site and At least one of the secondary electrons, the reflected electrons, and the backscattered electrons having an optical axis reference emission angle corresponding to the geometric shape of the inspection target part so that an image contrast with an adjacent part is high. Electron selection means for selectively forming an image on the detection surface of the electron beam detection means;
A substrate inspection apparatus is provided.

本発明によれば、基板の欠陥を高感度で検出することができる。
また、本発明によれば、上記効果を奏する基板検査方法を用いるので、高い歩留まりで半導体装置を製造することができる。 According to the present invention, it is possible to detect a substrate defect with high sensitivity.
Further, according to the present invention, since the substrate inspection method that exhibits the above effect is used, a semiconductor device can be manufactured with a high yield.

以下、本発明の実施の形態について図面を参照しながら説明する。本明細書においては、すべての検査対象部位で二次電子等の放出する角度の基準を共通にするため、二次光学系の光軸方向を基準として採用し、二次電子等の放出する方向と二次光学系の光軸方向とがなす角度を「光軸基準放出角度」と定義する。また、角度の正負の符号について反時計方向を正の方向とする。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this specification, in order to make the reference of the angle at which secondary electrons etc. are emitted common to all inspection target parts, the optical axis direction of the secondary optical system is adopted as a reference, and the direction in which secondary electrons etc. are emitted. And the optical axis direction of the secondary optical system are defined as “optical axis reference emission angle”. Further, the counterclockwise direction is a positive direction with respect to the sign of the angle.

図１は、本発明の第１の実施の形態にかかる基板検査装置の概略構成を示すブロック図である。本実施形態の特徴は、検査対象部位の幾何学的形状に対応した形状およびサイズを有する複数の絞り８１Ｂα〜８１Ｂγ，８１Ｄα〜８１Ｄγを可動絞り板８１に設け、可動絞り板駆動部８３により可動絞り板８１を移動させることにより検査対象部位に応じた絞りを選択する点にある。この点は後に詳述する。 FIG. 1 is a block diagram showing a schematic configuration of the substrate inspection apparatus according to the first embodiment of the present invention. A feature of the present embodiment is that a plurality of stops 81Bα to 81Bγ and 81Dα to 81Dγ having shapes and sizes corresponding to the geometric shape of the region to be inspected are provided on the movable stop plate 81, and the movable stop plate driving unit 83 moves the movable stop. By moving the plate 81, the diaphragm according to the inspection object part is selected. This point will be described in detail later.

図１に示す基板検査装置１は、一次光学系１０と、二次光学系２０と、電子検出部３０と、ウィーンフィルタ（Wien filter）４１と、ステージ４３と、各種制御部１６，１７，５１〜５５，５７と、画像信号処理部５８と、ホストコンピュータ６０と、表示部６２と、を備える。 A substrate inspection apparatus 1 shown in FIG. 1 includes a primary optical system 10, a secondary optical system 20, an electron detection unit 30, a Wien filter 41, a stage 43, and various control units 16, 17, 51. ˜55, 57, an image signal processing unit 58, a host computer 60, and a display unit 62.

一次光学系１０は、電子銃部１１と複数段の四極子レンズ１５を含む。電子銃部１１は、例えば一次電子ビーム照射手段に対応し、長軸１００〜７００μｍ、短軸１５μｍの矩形の電子放出面を有するＬａＢ６線状陰極１１２、ウエーネルト電極１１４、電子ビームの引き出しを行う陽極１１６、光軸調整用の偏向器１１８を有する。ＬａＢ６線状陰極１１２、ウエーネルト電極１１４、陽極１１６および偏向器１１８は制御部１６に接続され、この制御部１６からの信号により一次電子ビームＢｐの加速電圧、出射電流、光軸Ａｐが制御される。四極子レンズ１５は、四極子レンズ制御部１７に接続される。線状陰極１１２より放出した一次電子ビームＢｐは、四極子レンズ制御部１７からの信号により制御される四極子レンズ１５によって収束され、ウィーンフィルタ４１に対して斜めから入射する。一次電子ビームＢｐはウィーンフィルタ４１によって偏向され、試料である基板Ｓに対して垂直な方向に進行する。一次電子ビームＢｐはその後、二次光学系２０内の回転対称静電レンズであるカソードレンズ２１によってレンズ作用を受け、基板Ｓに対して垂直に照射される。 The primary optical system 10 includes an electron gun unit 11 and a plurality of stages of quadrupole lenses 15. The electron gun unit 11 corresponds to, for example, primary electron beam irradiation means, and includes a LaB6 linear cathode 112 having a rectangular electron emission surface having a major axis of 100 to 700 μm and a minor axis of 15 μm, a Wehnelt electrode 114, and an anode for extracting an electron beam. 116 and a deflector 118 for adjusting the optical axis. The LaB6 linear cathode 112, the Wehnelt electrode 114, the anode 116, and the deflector 118 are connected to the control unit 16, and the acceleration voltage, emission current, and optical axis Ap of the primary electron beam Bp are controlled by signals from the control unit 16. . The quadrupole lens 15 is connected to the quadrupole lens control unit 17. The primary electron beam Bp emitted from the linear cathode 112 is converged by the quadrupole lens 15 controlled by a signal from the quadrupole lens control unit 17 and is incident on the Wien filter 41 from an oblique direction. The primary electron beam Bp is deflected by the Wien filter 41 and travels in a direction perpendicular to the substrate S which is a sample. Thereafter, the primary electron beam Bp is subjected to a lens action by a cathode lens 21 which is a rotationally symmetric electrostatic lens in the secondary optical system 20 and is irradiated perpendicularly to the substrate S.

基板Ｓはステージ４３の上面に設置され、ステージ電圧制御部５１により基板Ｓに負電圧が印加できるようになっている。この機構は、一次電子ビームＢｐによる基板Ｓへの入射ダメージを低減し、一次電子ビームＢｐの照射によって、基板Ｓ表面の形状／材質／電位の変化に応じて発生した二次電子、反射電子および後方散乱電子で構成される二次電子ビームＢｓのエネルギ向上を目的としたものである。二次電子、反射電子および後方散乱電子は、例えば二次電子、反射電子および後方散乱電子に対応する。以下では、二次電子、反射電子および後方散乱電子を単に二次電子等という。 The substrate S is installed on the upper surface of the stage 43, and a negative voltage can be applied to the substrate S by the stage voltage control unit 51. This mechanism reduces incident damage to the substrate S due to the primary electron beam Bp, and secondary electrons, reflected electrons, and reflected electrons generated according to changes in the shape / material / potential of the surface of the substrate S due to the irradiation of the primary electron beam Bp. The purpose is to improve the energy of the secondary electron beam Bs composed of backscattered electrons. Secondary electrons, reflected electrons, and backscattered electrons correspond to, for example, secondary electrons, reflected electrons, and backscattered electrons. Hereinafter, secondary electrons, reflected electrons, and backscattered electrons are simply referred to as secondary electrons.

ウィーンフィルタ４１の具体的構成を図２に示し、その作動原理を図３および図４を参照しながら簡単に説明する。図２に示すように、ウィーンフィルタ４１の場は、二次光学系の光軸Ａｓに垂直な平面ＣＳｗ（図３，図４参照）内で電界Ｅと磁界Ｂとを直交させた構造になっており、入射した電子に対して、ウィーン条件ｑＥ＝ｖＢ（ｑは粒子電荷、ｖは直進電子の速度）を満たす電子のみを直進させる働きをする。図３に示すように、この検査装置１では、一次電子ビームＢｐに対しては磁界による力ＦＢと電界による力ＦＥが同一方向に作用して、一次電子ビームＢｐは基板Ｓに対して垂直に入射するように偏向される。また、二次電子ビームＢｓに対しては、図４に示すように、ＦＢとＦＥが逆方向に作用し、なおかつウィーン条件ＦＢ＝ＦＥが成立しているため、二次電子ビームＢｓは偏向されずに直進して二次光学系に入射する。 A specific configuration of the Wien filter 41 is shown in FIG. 2, and its operating principle will be briefly described with reference to FIGS. As shown in FIG. 2, the field of the Wien filter 41 has a structure in which the electric field E and the magnetic field B are orthogonal to each other in a plane CSw (see FIGS. 3 and 4) perpendicular to the optical axis As of the secondary optical system. In this case, only electrons that satisfy the Wien condition qE = vB (q is the particle charge and v is the velocity of the straight electron) are caused to travel straight. As shown in FIG. 3, in this inspection apparatus 1, the force FB caused by the magnetic field and the force FE caused by the electric field act on the primary electron beam Bp in the same direction, and the primary electron beam Bp is perpendicular to the substrate S. It is deflected to be incident. Further, as shown in FIG. 4, the secondary electron beam Bs is deflected with respect to the secondary electron beam Bs because FB and FE act in opposite directions and the Wien condition FB = FE is satisfied. Without going straight, it enters the secondary optical system.

図１に戻り、二次光学系２０は、例えば写像投影手段に対応し、カソードレンズ２１、第二レンズ２２、第三レンズ２３と、第二レンズ２２と第三レンズ２３との間に設置された可動絞り板８１と視野絞り２６とを含む。可動絞り板８１および視野絞り２６は、後述するホストコンピュータ６０とともに、例えば電子選択手段に対応する。可動絞り板８１は、基板Ｓと電子検出部３０との間で二次電子ビームＢｓの焦点面２４に配置され、可動絞り板駆動部８３に接続される。可動絞り板駆動部８３は、ホストコンピュータ６０に接続され、その指令信号を受けて検査対象部位に応じた絞りが光軸上に配置されるように、可動絞り板８１を焦点面２４内で移動させる。カソードレンズ２１、第二レンズ２２、第三レンズ２３は、二次光学系レンズ制御部５２、５４、５５にそれぞれ接続され、これらの制御部から与えられる制御信号により、二次電子ビームＢｓを拡大投影し、二次電子ビーム像をＭＣＰ（Micro Channel Plate）検出器３１の検出面に結像させる。 Returning to FIG. 1, the secondary optical system 20 corresponds to, for example, a mapping projection unit, and is installed between the cathode lens 21, the second lens 22, the third lens 23, and the second lens 22 and the third lens 23. The movable diaphragm plate 81 and the field diaphragm 26 are included. The movable aperture plate 81 and the field aperture 26 correspond to, for example, electronic selection means together with the host computer 60 described later. The movable diaphragm plate 81 is disposed on the focal plane 24 of the secondary electron beam Bs between the substrate S and the electron detection unit 30 and is connected to the movable diaphragm plate driving unit 83. The movable diaphragm plate drive unit 83 is connected to the host computer 60 and receives the command signal to move the movable diaphragm plate 81 within the focal plane 24 so that the diaphragm corresponding to the inspection target part is arranged on the optical axis. Let The cathode lens 21, the second lens 22, and the third lens 23 are connected to the secondary optical system lens control units 52, 54, and 55, respectively, and the secondary electron beam Bs is expanded by control signals given from these control units. Projection is performed, and a secondary electron beam image is formed on the detection surface of an MCP (Micro Channel Plate) detector 31.

電子検出部３０は、例えば電子ビーム検出手段に対応し、基板Ｓに対向する検出面を有するＭＣＰ検出器３１と、蛍光板３２と、ライトガイド３３と、ＣＣＤ（Charged Coupled Device）等の撮像素子３４とを含む。ＭＣＰ検出器３１の検出面に入射した二次電子ビームＢｓはＭＣＰにより増幅されて蛍光板３２に照射する。蛍光板３２で発生した蛍光像はライトガイド３３を介して撮像素子３４で検出される。撮像素子３４により検出された信号は、画像処理部５８で処理されて画像データとしてホストコンピュータ６０に転送される。 The electron detection unit 30 corresponds to, for example, an electron beam detection unit, and includes an MCP detector 31 having a detection surface facing the substrate S, a fluorescent plate 32, a light guide 33, and an imaging device 34 such as a CCD (Charged Coupled Device). Including. The secondary electron beam Bs incident on the detection surface of the MCP detector 31 is amplified by the MCP and applied to the fluorescent screen 32. The fluorescent image generated on the fluorescent plate 32 is detected by the image sensor 34 through the light guide 33. The signal detected by the image sensor 34 is processed by the image processing unit 58 and transferred to the host computer 60 as image data.

ホストコンピュータ６０は、各種制御部１６，１７，５１〜５５，５７に接続され、これらの制御部を介して装置全体を制御する。ホストコンピュータ６０はまた可動絞り板駆動部８３に接続され、所望の検査対象部位の画像信号の量が増大するように、または、所望の検査対象部位とこれに隣接する部位とのコントラストが向上するように、可動絞り板８１による二次電子ビームＢｓの通過制限を調整するための指令信号を生成して可動絞り板駆動部８３に供給する。さらに、ホストコンピュータ６０は画像信号処理部５８および表示部６２にも接続され、画像信号処理部５８から画像データの供給を受け、図示しない画像メモリに保存し、二次電子ビーム像を表示装置６０により表示させる他、検査目的に応じた画像処理等により欠陥検出処理等を実行する。 The host computer 60 is connected to various control units 16, 17, 51 to 55, 57, and controls the entire apparatus via these control units. The host computer 60 is also connected to the movable diaphragm driving unit 83 so that the amount of image signal of the desired inspection target region is increased or the contrast between the desired inspection target region and the adjacent region is improved. As described above, a command signal for adjusting the passage restriction of the secondary electron beam Bs by the movable diaphragm plate 81 is generated and supplied to the movable diaphragm plate driving unit 83. Further, the host computer 60 is also connected to the image signal processing unit 58 and the display unit 62, receives image data from the image signal processing unit 58, stores it in an image memory (not shown), and displays the secondary electron beam image on the display device 60. In addition to displaying the image, defect detection processing or the like is executed by image processing or the like according to the inspection purpose.

図５に示すように、可動絞り板８１には円孔形状の絞り８１Ｂα〜８１Ｂγとリング形状の開口を有する絞り８１Ｄα〜８１Ｄγとが設けられている。図５のＡ−Ａ断面図を図６に示し、図５のＢ−Ｂ断面図を図７に示す。 As shown in FIG. 5, the movable aperture plate 81 is provided with circular apertures 81Bα to 81Bγ and apertures 81Dα to 81Dγ having ring-shaped openings. FIG. 6 is a cross-sectional view taken along the line AA in FIG. 5, and FIG. 7 is a cross-sectional view taken along the line BB in FIG.

図１に示す基板検査装置１は、可動絞り板駆動部８３により可動絞り板８１を移動させることにより、検査対象部位の幾何学的形状に応じて所望の角度で放出する二次電子等で構成される二次電子ビームがＭＣＰ検出器３１の検出面で結像するように、検査対象部位に対応する絞りを選択して光軸上に配置する。 The substrate inspection apparatus 1 shown in FIG. 1 includes secondary electrons that are emitted at a desired angle in accordance with the geometric shape of the region to be inspected by moving the movable diaphragm plate 81 by the movable diaphragm plate driving unit 83. The diaphragm corresponding to the site to be inspected is selected and placed on the optical axis so that the secondary electron beam to be imaged on the detection surface of the MCP detector 31.

一般的に、二次電子等の放出角度φ（二次電子等が放出する方向と二次電子等が放出する表面の放線方向となす角度）とその放出比Ｓ（放出する二次電子等の量／入射する電子の量）との間には、
Ｓ＝Ａｃｏｓφ（Ａは係数） (1)
の関係が成り立つ。即ち、ある面からの二次電子等の放出比は、その面の法線方向が最大となる。ここで、図８のパターンＰに示すように、同一または類似の材質で構成される検査対象パターンがテーパ状の側壁部または傾斜部ＳＷを有する場合、パターンＰの頂面ＴＳおよび底面ＢＳでは、二次電子等の放出面の法線方向は二次光学系の光軸方向Ａｓと一致するように設置されるため、頂面ＴＳおよび底面ＢＳに垂直な方向で二次電子等の放出比が最大になる。従って、光軸となす角度のうち相対的に小さな鋭角、同図では−θ１〜＋θ１の範囲に含まれる放出角度の二次電子等をＭＣＰ検出器３１の検出面で投影結像させれば、パターンＰの頂面ＴＳおよび底面ＢＳが明部となる画像が得られる。この場合は相対的に大きな鋭角、図８ではθ２〜θ３の範囲に含まれる放出角度の二次電子等はＭＣＰ検出器３１で結像しないように写像投影光学系内で遮断される。 In general, the emission angle φ of secondary electrons, etc. (the angle between the direction in which secondary electrons etc. are emitted and the normal direction of the surface from which secondary electrons etc. are emitted) and its emission ratio S (such as secondary electrons to be emitted) (Quantity / quantity of incident electrons)
S = Acosφ (A is a coefficient) (1)
The relationship holds. That is, the emission ratio of secondary electrons from a certain surface is maximized in the normal direction of the surface. Here, as shown in the pattern P of FIG. 8, when the inspection target pattern made of the same or similar material has a tapered side wall portion or inclined portion SW, the top surface TS and the bottom surface BS of the pattern P are: Since the normal direction of the emission surface of secondary electrons and the like is set to coincide with the optical axis direction As of the secondary optical system, the emission ratio of secondary electrons and the like is perpendicular to the top surface TS and the bottom surface BS. Become the maximum. Accordingly, if a secondary electron having an emission angle included in the range of −θ1 to + θ1 in the figure is relatively small among the angles formed with the optical axis, and projected on the detection surface of the MCP detector 31, An image in which the top surface TS and the bottom surface BS of the pattern P are bright portions is obtained. In this case, secondary electrons having a relatively large acute angle, that is, emission angles included in the range of θ2 to θ3 in FIG. 8 are blocked in the mapping projection optical system so as not to be imaged by the MCP detector 31.

この一方、パターンＰの側壁部または傾斜部ＳＷでは、二次電子等の放出面の法線方向は二次光学系の光軸方向Ａｓと相対的に大きな鋭角、図８では（θ２＋θ３）／２の角度をなし、θ２〜θ３の範囲に含まれる角度で放出される二次電子をＭＣＰ検出器３１の検出面で投影結像させれば、パターンＰの側壁部または傾斜部ＳＷが明部となる画像を得ることができる。この場合、相対的に小さな鋭角、図８では−θ１〜＋θ１の範囲に含まれる角度で放出される二次電子等はＭＣＰ検出器３１で結像しないように写像投影光学系内で遮断される。 On the other hand, in the side wall portion or the inclined portion SW of the pattern P, the normal direction of the emission surface of secondary electrons or the like is a relatively large acute angle with the optical axis direction As of the secondary optical system, and in FIG. 8, (θ2 + θ3) / 2 When the secondary electrons emitted at an angle included in the range of θ2 to θ3 are projected and imaged on the detection surface of the MCP detector 31, the side wall portion or the inclined portion SW of the pattern P becomes the bright portion. Can be obtained. In this case, secondary electrons and the like emitted at a relatively small acute angle, that is, an angle included in the range of −θ1 to + θ1 in FIG. 8, are blocked in the projection optical system so as not to form an image with the MCP detector 31. .

本明細書においては、パターンの頂面および底面が明部となり、パターンエッジ部、または側壁部もしくは傾斜部が暗部となって検出系に投影される光学系モードを「明視野モード」と定義し、この一方、パターンエッジ部または側壁部もしくは傾斜部が明部となり、パターンの頂面ＴＳおよび底面ＢＳが暗部となって検出系に投影される光学系モードを「暗視野モード」と定義する。「明視野モード」では、二次電子等の放出比が最大になる光軸方向を中心に（図８では光軸基準放出角度−θ１〜＋θ１の範囲で）パターンの頂面および底面から放出した二次電子等で構成される二次電子ビームの通過を許容する開口絞りを選択する。図５に示す例では、円孔絞り８１Ｂα〜８１Ｂγを使用すればよい。また、「暗視野モード」では、二次電子等の放出比が最大になる、放出面の法線方向を中心に（図８では光軸基準放出角度θ２〜θ３の範囲で）パターンの側壁部または傾斜部ＳＷから放出した二次電子等で構成される二次電子ビームの通過を許容し、かつ、光軸基準放出角度−θ１〜＋θ１の二次電子等で構成される二次電子ビームを遮断する開口絞りを選択する。図５に示す例では、リング形状の開口を有する絞り８１Ｄα〜８１Ｄγを使用すればよい。検査・計測したいパターンの部位が明部となる最適な絞りが選択されるように、ホストコンピュータ６０が可動絞り板駆動部８３へ制御信号を供給する。可動絞り駆動部８３はホストコンピュータ６０からの制御信号に従い、可動絞り板８１を駆動させ、可動絞り板８１上で検査・計測に最適な絞りによる二次電子ビームＢｓの通過制限調整を行う。可動絞り駆動部８３を介してホストコンピュータ６０により絞りの位置が調整された可動絞り板８１は、検査対象部位の幾何学的形状に応じた光軸基準放出角度以外の光軸基準放出角度を有する二次電子等で構成される二次電子ビームを前記基板と前記電子ビーム検出手段との間で遮蔽する。 In this specification, the optical system mode that is projected onto the detection system with the top and bottom surfaces of the pattern as the bright part and the pattern edge part, or the side wall or inclined part as the dark part is defined as the “bright field mode”. On the other hand, an optical system mode projected onto the detection system with the pattern edge portion or side wall portion or inclined portion being a bright portion and the top surface TS and bottom surface BS of the pattern being a dark portion is defined as a “dark field mode”. In “bright field mode”, light is emitted from the top and bottom surfaces of the pattern around the optical axis direction where the emission ratio of secondary electrons and the like is maximized (in the range of optical axis reference emission angles −θ1 to + θ1 in FIG. 8). An aperture stop that allows passage of a secondary electron beam composed of secondary electrons or the like is selected. In the example shown in FIG. 5, circular aperture stops 81Bα to 81Bγ may be used. Further, in the “dark field mode”, the side wall portion of the pattern is centered on the normal direction of the emission surface (in the range of optical axis reference emission angles θ2 to θ3 in FIG. 8) at which the emission ratio of secondary electrons and the like is maximized. Alternatively, a secondary electron beam configured to allow passage of a secondary electron beam composed of secondary electrons emitted from the inclined portion SW and composed of secondary electrons having an optical axis reference emission angle of −θ1 to + θ1 is used. Select the aperture stop to block. In the example shown in FIG. 5, the diaphragms 81Dα to 81Dγ having ring-shaped openings may be used. The host computer 60 supplies a control signal to the movable diaphragm plate driving unit 83 so that an optimum diaphragm is selected so that the portion of the pattern to be inspected / measured is a bright part. The movable diaphragm driving unit 83 drives the movable diaphragm plate 81 in accordance with a control signal from the host computer 60, and performs the passage restriction adjustment of the secondary electron beam Bs with the diaphragm optimum for inspection and measurement on the movable diaphragm plate 81. The movable diaphragm plate 81 whose position has been adjusted by the host computer 60 via the movable diaphragm driving unit 83 has an optical axis reference emission angle other than the optical axis reference emission angle corresponding to the geometric shape of the inspection target part. A secondary electron beam composed of secondary electrons or the like is shielded between the substrate and the electron beam detection means.

明視野モードにおけるパターンＰ頂面ＴＳ内の１点ＲｇＡから放出した二次電子ビームＢｓａの光線図を図９に示し、パターンＰ底面ＢＳ内の２点ＲｇＢ，ＲｇＣから放出した二次電子ビームＢｓｂ，Ｂｓｃの光線図を図１０に示し、パターンＰの両側壁ＳＷ内の各点ＲｇＤ，ＲｇＥから放出した二次電子ビームＢｓｅ，Ｂｓｄの光線図を図１１に示す。この明視野モードでは光軸基準放出角−θ１〜＋θ１の二次電子等が通過できるように可動絞り板８１上の対応する絞りが設定されている。例えば図１１では、ＲｇＤおよびＲｇＥから放出した二次電子ビームＢｓｅ，Ｂｓｄよりも、ＲｇＡ，ＲｇＢ，ＲｇＣから放出した二次電子ビームＢｓａ，Ｂｓｂ，Ｂｓｃの方がＭＣＰ検出器３１にて検出される電子信号量が多いために、図８のパターンＰを本装置の明視野モードにて撮像すると、図１２のような明視野像が得られる。 FIG. 9 shows a ray diagram of the secondary electron beam Bsa emitted from one point RgA in the pattern P top surface TS in the bright field mode, and the secondary electron beam Bsb emitted from the two points RgB and RgC in the pattern P bottom surface BS. , Bsc is shown in FIG. 10, and the secondary electron beams Bse, Bsd emitted from the points RgD, RgE in the side walls SW of the pattern P are shown in FIG. In this bright field mode, the corresponding diaphragm on the movable diaphragm plate 81 is set so that secondary electrons of the optical axis reference emission angles −θ1 to + θ1 can pass through. For example, in FIG. 11, the secondary electron beams Bsa, Bsb, and Bsc emitted from RgA, RgB, and RgC are detected by the MCP detector 31 rather than the secondary electron beams Bse and Bsd emitted from RgD and RgE. Since the amount of electronic signals is large, when the pattern P in FIG. 8 is imaged in the bright field mode of the present apparatus, a bright field image as shown in FIG. 12 is obtained.

暗視野モードにおけるパターンＰ頂面ＴＳ内の１点ＲｇＡから放出した二次電子ビームＢｓａの光線図を図１３に示し、パターンＰ底面ＢＳ内の２点ＲｇＢ，ＲｇＣから放出した二次電子ビームＢｓｂ，Ｂｓｃの光線図を図１４に示し、パターンＰの両側壁ＳＷ内の各点ＲｇＤ，ＲｇＥから放出した二次電子ビームＢｓｅ，Ｂｓｄの光線図を図１５に示す。この暗視野モードでは光軸基準放出角−θ３〜−θ２，＋θ２〜＋θ３の二次電子等が透過できるように可動絞り板８１上の対応する絞りが設定されている。例えば図１５では、ＲｇＡ，ＲｇＢ，ＲｇＣから放出した二次電子ビームＢｓａ，Ｂｓｂ，Ｂｓｃよりも、ＲｇＤおよびＲｇＥから放出した二次電子ビームＢｓｄ，Ｂｓｅの方がＭＣＰ検出器３１にて検出される電子信号量が多いために、図８のパターンＰを本装置の暗視野モードにて撮像すると、図１６のような暗視野像が得られる。 FIG. 13 shows a ray diagram of the secondary electron beam Bsa emitted from one point RgA in the pattern P top surface TS in the dark field mode, and the secondary electron beam Bsb emitted from the two points RgB and RgC in the pattern P bottom surface BS. , Bsc is shown in FIG. 14, and secondary electron beams Bse, Bsd emitted from the points RgD, RgE in the side walls SW of the pattern P are shown in FIG. 15. In this dark field mode, the corresponding diaphragm on the movable diaphragm plate 81 is set so that secondary electrons of the optical axis reference emission angles −θ3 to −θ2 and + θ2 to + θ3 can be transmitted. For example, in FIG. 15, the MCP detector 31 detects the secondary electron beams Bsd and Bse emitted from RgD and RgE rather than the secondary electron beams Bsa, Bsb and Bsc emitted from RgA, RgB and RgC. Since the amount of electronic signal is large, when the pattern P in FIG. 8 is imaged in the dark field mode of the present apparatus, a dark field image as shown in FIG. 16 is obtained.

暗視野モードにおいて、パターンエッジ部のコントラストを強調したい場合は、パターンエッジ部から放出してＭＣＰ検出器３１の検出面で結像する二次電子等の量と、パターンエッジ部に隣接する部位（側壁ＳＷ、頂面ＴＳ、底面ＢＳ等）から放出してＭＣＰ検出器３１の検出面で結像する二次電子ビーム量の差が顕著になればよい。そのためには、図７の断面図に示すような暗視野モード用絞りを適用すればよいが、上記条件を満たすように例えば暗視野モード用絞りの遮断用円盤の直径Ｄ１と透過用絞り孔の径Ｄ２の最適化を行えばよい。このように最適化された暗視野モード絞りを使用することにより、図１７に示すようにエッジ部ＴＥ，ＴＢが強調された暗視野像が得られる。 In the dark field mode, when it is desired to enhance the contrast of the pattern edge portion, the amount of secondary electrons or the like emitted from the pattern edge portion and imaged on the detection surface of the MCP detector 31 and the portion adjacent to the pattern edge portion ( The difference in the amount of secondary electron beams emitted from the side wall SW, the top surface TS, the bottom surface BS, and the like and imaged on the detection surface of the MCP detector 31 should be significant. For this purpose, a dark field mode stop as shown in the cross-sectional view of FIG. 7 may be applied. In order to satisfy the above condition, for example, the diameter D1 of the dark field mode stop disc and the transmission stop hole The diameter D2 may be optimized. By using the dark field mode diaphragm optimized as described above, a dark field image in which the edge portions TE and TB are emphasized as shown in FIG. 17 is obtained.

なお、本実施形態では、明視野モードおよび暗視野モードのための絞りとして回転対称形状のものを用いたが、絞りの形状はこれに限ることなく、測定対象パターンの幾何学的形状に応じて、例えば図１８の符号８１Ｄａｓに示すように非対称形状の絞りでも良い。 In the present embodiment, a rotationally symmetric shape is used as the diaphragm for the bright field mode and the dark field mode. However, the shape of the diaphragm is not limited to this, and depends on the geometric shape of the measurement target pattern. For example, as shown by reference numeral 81 Das in FIG.

このように本実施形態によれば、パターンの側壁部を含む所望の測定対象部位に応じた二次電子像を取得することができる。また、パターンエッジ部でのコントラストも強調されるので、パターン欠陥検出感度が向上する。 As described above, according to the present embodiment, it is possible to acquire a secondary electron image corresponding to a desired measurement target region including the side wall portion of the pattern. Further, since the contrast at the pattern edge portion is also enhanced, the pattern defect detection sensitivity is improved.

上述した一連の検査方法を用いて半導体装置を製造することにより、高い歩留まりでかつ低コストで半導体装置を製造することが可能になる。 By manufacturing a semiconductor device using the above-described series of inspection methods, it is possible to manufacture a semiconductor device with high yield and low cost.

以上、本発明の実施の形態について説明したが、本発明は上記形態に限ることなく、その技術的範囲内で種々変形して適用することが可能である。 Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be applied within the technical scope thereof.

本発明の第１の実施の形態にかかる基板検査装置の概略構成を示すブロック図である。It is a block diagram showing a schematic structure of a substrate inspection device concerning a 1st embodiment of the present invention. 図１に示す基板検査装置が備えるウィーンフィルタの具体的構成を示す斜視図である。It is a perspective view which shows the specific structure of the Wien filter with which the board | substrate inspection apparatus shown in FIG. 1 is provided. 図２に示すウィーンフィルタの作動原理の説明図である。It is explanatory drawing of the principle of operation of the Wien filter shown in FIG. 図２に示すウィーンフィルタの作動原理の説明図である。It is explanatory drawing of the principle of operation of the Wien filter shown in FIG. 図１に示す基板検査装置が備える可動絞り板に設けられた絞りを示す平面図である。It is a top view which shows the aperture | diaphragm provided in the movable aperture plate with which the board | substrate inspection apparatus shown in FIG. 1 is provided. 図５のＡ−Ａ断面図である。It is AA sectional drawing of FIG. 図５のＢ−Ｂ断面図であるIt is BB sectional drawing of FIG. 検査対象パターンの一例を示す断面図である。It is sectional drawing which shows an example of a test object pattern. 図１に示す基板検査装置の明視野モードにおける二次電子ビームの光線図の一例を示す。An example of the ray diagram of the secondary electron beam in the bright field mode of the board | substrate inspection apparatus shown in FIG. 1 is shown. 図１に示す基板検査装置の明視野モードにおける二次電子ビームの光線図の他の一例を示す。FIG. 6 shows another example of a ray diagram of a secondary electron beam in the bright field mode of the substrate inspection apparatus shown in FIG. 図１に示す基板検査装置の明視野モードにおける二次電子ビームの光線図のさらに他の一例を示す。FIG. 6 shows still another example of a ray diagram of a secondary electron beam in the bright field mode of the substrate inspection apparatus shown in FIG. 1. 図１に示す基板検査装置により得られた明視野像の一例を示す。An example of the bright-field image obtained by the board | substrate inspection apparatus shown in FIG. 図１に示す基板検査装置の暗視野モードにおける二次電子ビームの光線図の一例を示す。An example of the ray diagram of the secondary electron beam in the dark field mode of the board | substrate inspection apparatus shown in FIG. 1 is shown. 図１に示す基板検査装置の暗視野モードにおける二次電子ビームの光線図の他の一例を示す。FIG. 6 shows another example of a ray diagram of a secondary electron beam in the dark field mode of the substrate inspection apparatus shown in FIG. 図１に示す基板検査装置の暗視野モードにおける二次電子ビームの光線図のさらに他の一例を示す。FIG. 6 shows still another example of the ray diagram of the secondary electron beam in the dark field mode of the substrate inspection apparatus shown in FIG. 1. 図１に示す基板検査装置により得られた暗視野像の一例を示す。An example of the dark field image obtained by the board | substrate inspection apparatus shown in FIG. 1 is shown. 図１に示す基板検査装置により得られ、エッジ部が強調された暗視野像の一例を示す。An example of a dark field image obtained by the substrate inspection apparatus shown in FIG. 非対称形状の絞りの一例を示す平面図である。It is a top view which shows an example of an asymmetrical aperture stop.

符号の説明Explanation of symbols

１基板検査装置
１０一次光学系
１１電子銃部
１５四極子レンズ
１６，１７，５１〜５５，５７各種制御部
２０二次光学系
２４二次電子ビームの焦点面
３０電子検出部
３１ＭＣＰ検出器
４１ウィーンフィルタ
４３ステージ
５８画像信号処理部
６０ホストコンピュータ
６２表示部
８１可動絞り板
８１Ｂα〜８１Ｂγ 円孔形状の絞り
８１Ｄα〜８１Ｄγ リング形状の開口を有する絞り
８３可動絞り板駆動部
１１２ＬａＢ６線状陰極
Ｂｐ一次電子ビーム
Ｂｓ二次電子ビーム
ＴＳ頂面
ＢＳ底面
ＳＷパターンの側壁部または傾斜部 DESCRIPTION OF SYMBOLS 1 Board | substrate inspection apparatus 10 Primary optical system 11 Electron gun part 15 Quadrupole lens 16, 17, 51-55, 57 Various control parts 20 Secondary optical system 24 Focal plane 30 of a secondary electron beam Electron detection part 31 MCP detector 41 Wien filter 43 Stage 58 Image signal processing unit 60 Host computer 62 Display unit 81 Movable diaphragm plates 81Bα to 81Bγ Circular apertures 81Dα to 81Dγ Diaphragm having ring-shaped openings 83 Movable diaphragm plate drive unit 112 LaB6 linear cathode Bp Primary Electron beam Bs Secondary electron beam TS Top surface BS Bottom surface SW Side wall portion or inclined portion of pattern

Claims

電子ビームを生成して試料である基板に一次電子ビームとして照射する工程と、
前記一次電子ビームの照射を受けて前記基板から放出される二次電子、反射電子および後方散乱電子の少なくともいずれかを導いて二次電子ビームとして拡大投影し、結像させる写像投影工程と、
結像した前記二次電子ビームを検出して前記基板の状態を表す画像信号を出力する工程と、
を備える基板検査方法であって、
前記写像投影工程は、
前記二次電子、前記反射電子および前記後方散乱電子の少なくともいずれかの放出方向と前記二次電子ビームの光軸との角度を光軸基準放出角度と定義すると、任意の検査対象部位の画像信号の量が他の部位の画像信号の量よりも増大するように、前記検査対象部位の幾何学的形状に応じた光軸基準放出角度を有する前記二次電子、前記反射電子および前記後方散乱電子の少なくともいずれかを選択的に結像させる工程を含む、
基板検査方法。 A step of generating an electron beam and irradiating the sample substrate as a primary electron beam;
A mapping projecting step in which at least one of secondary electrons, reflected electrons, and backscattered electrons emitted from the substrate in response to irradiation of the primary electron beam is led to be enlarged and projected as a secondary electron beam, and imaged;
Detecting the imaged secondary electron beam and outputting an image signal representing the state of the substrate;
A substrate inspection method comprising:
The mapping projection step includes:
When an angle between an emission direction of at least one of the secondary electrons, the reflected electrons, and the backscattered electrons and an optical axis of the secondary electron beam is defined as an optical axis reference emission angle, an image signal of an arbitrary inspection target site The secondary electrons, the backscattered electrons, and the backscattered electrons having an optical axis reference emission angle corresponding to the geometric shape of the region to be inspected so that the amount of image signals is larger than the amount of image signals of other regions. Selectively imaging at least one of
Board inspection method.

電子ビームを生成して試料である基板に一次電子ビームとして照射する工程と、
前記一次電子ビームの照射を受けて前記基板から放出される二次電子、反射電子および後方散乱電子の少なくともいずれかを導いて二次電子ビームとして拡大投影し、結像させる写像投影工程と、
結像した前記二次電子ビームを検出して前記基板の状態を表す画像信号を出力する工程と、
を備える基板検査方法であって、
前記写像投影工程は、
前記二次電子、前記反射電子および前記後方散乱電子の少なくともいずれかの放出方向と前記二次電子ビームの光軸との角度を光軸基準放出角度と定義すると、任意の検査対象部位とこれに隣接する部位との画像コントラストが高くなるように、前記検査対象部位の幾何学的形状に応じた光軸基準放出角度を有する前記二次電子、前記反射電子および前記後方散乱電子の少なくともいずれかを選択的に結像させる工程を含む、
基板検査方法。 A step of generating an electron beam and irradiating the sample substrate as a primary electron beam;
A mapping projecting step in which at least one of secondary electrons, reflected electrons, and backscattered electrons emitted from the substrate in response to irradiation of the primary electron beam is led to be enlarged and projected as a secondary electron beam, and imaged;
Detecting the imaged secondary electron beam and outputting an image signal representing the state of the substrate;
A substrate inspection method comprising:
The mapping projection step includes:
When the angle between the emission direction of at least one of the secondary electrons, the reflected electrons, and the backscattered electrons and the optical axis of the secondary electron beam is defined as an optical axis reference emission angle, an arbitrary inspection target site and At least one of the secondary electrons, the reflected electrons, and the backscattered electrons having an optical axis reference emission angle corresponding to the geometric shape of the inspection target part so that an image contrast with an adjacent part is high. Including selectively imaging.
Board inspection method.

請求項１または２に記載の基板検査方法を備える半導体装置の製造方法。 A method of manufacturing a semiconductor device comprising the substrate inspection method according to claim 1.

電子ビームを生成して試料である基板に一次電子ビームとして照射する一次ビーム照射手段と、
前記一次電子ビームの照射を受けて前記基板から放出される二次電子、反射電子および後方散乱電子の少なくともいずれかを導いて二次電子ビームとして拡大投影して結像させる写像投影手段と、
前記二次電子ビームが結像する検出面を有し、前記検出面で前記二次電子ビームを検出して前記基板の状態を表す画像信号を出力する電子ビーム検出手段と、
前記二次電子、前記反射電子および前記後方散乱電子の少なくともいずれかの放出方向と前記二次電子ビームの光軸との角度を光軸基準放出角度と定義すると、任意の検査対象部位の画像信号の量が他の部位の画像信号の量よりも増大するように、前記検査対象部位の幾何学的形状に応じた光軸基準放出角度を有する前記二次電子、前記反射電子および前記後方散乱電子の少なくともいずれかを選択的に前記電子ビーム検出手段の前記検出面に結像させる電子選択手段と、
を備える基板検査装置。 A primary beam irradiation means for generating an electron beam and irradiating the sample substrate as a primary electron beam;
Mapping projection means for directing at least one of secondary electrons, reflected electrons, and backscattered electrons emitted from the substrate upon irradiation of the primary electron beam and projecting it as a secondary electron beam to form an image;
An electron beam detector that has a detection surface on which the secondary electron beam forms an image, detects the secondary electron beam on the detection surface, and outputs an image signal representing the state of the substrate;
When an angle between an emission direction of at least one of the secondary electrons, the reflected electrons, and the backscattered electrons and an optical axis of the secondary electron beam is defined as an optical axis reference emission angle, an image signal of an arbitrary inspection target site The secondary electrons, the backscattered electrons, and the backscattered electrons having an optical axis reference emission angle corresponding to the geometric shape of the region to be inspected so that the amount of image signals is larger than the amount of image signals of other regions. Electron selection means for selectively imaging at least one of the above onto the detection surface of the electron beam detection means,
A board inspection apparatus comprising:

電子ビームを生成して試料である基板に一次電子ビームとして照射する一次電子ビーム照射手段と、
前記一次電子ビームの照射を受けて前記基板から放出される二次電子、反射電子および後方散乱電子の少なくともいずれかを導いて二次電子ビームとして拡大投影して結像させる写像投影手段と、
前記二次電子ビームが結像する検出面を有し、前記検出面で前記二次電子ビームを検出して前記基板の状態を表す画像信号を出力する電子ビーム検出手段と、
前記二次電子、前記反射電子および前記後方散乱電子の少なくともいずれかの放出方向と前記二次電子ビームの光軸との角度を光軸基準放出角度と定義すると、任意の検査対象部位とこれに隣接する部位との画像コントラストが高くなるように、前記検査対象部位の幾何学的形状に応じた光軸基準放出角度を有する前記二次電子、前記反射電子および前記後方散乱電子の少なくともいずれかを選択的に前記電子ビーム検出手段の前記検出面に結像させる電子選択手段と、
を備える基板検査装置。 A primary electron beam irradiation means for generating an electron beam and irradiating the substrate as a sample as a primary electron beam;
Mapping projection means for directing at least one of secondary electrons, reflected electrons, and backscattered electrons emitted from the substrate upon irradiation of the primary electron beam and projecting it as a secondary electron beam to form an image;
An electron beam detector that has a detection surface on which the secondary electron beam forms an image, detects the secondary electron beam on the detection surface, and outputs an image signal representing the state of the substrate;
When the angle between the emission direction of at least one of the secondary electrons, the reflected electrons, and the backscattered electrons and the optical axis of the secondary electron beam is defined as an optical axis reference emission angle, an arbitrary inspection target site and At least one of the secondary electrons, the reflected electrons, and the backscattered electrons having an optical axis reference emission angle corresponding to the geometric shape of the inspection target part so that an image contrast with an adjacent part is high. Electron selection means for selectively forming an image on the detection surface of the electron beam detection means;
A board inspection apparatus comprising: