JP2009087592A

JP2009087592A - Sample holding mechanism used in electron beam application device

Info

Publication number: JP2009087592A
Application number: JP2007252968A
Authority: JP
Inventors: Shigeru Haneda; 茂羽根田; Tetsuya Sawahata; 哲哉澤畠
Original assignee: Hitachi High Technologies Corp; Hitachi High Tech Corp
Current assignee: Hitachi High Tech Corp
Priority date: 2007-09-28
Filing date: 2007-09-28
Publication date: 2009-04-23
Anticipated expiration: 2027-09-28
Also published as: JP4997045B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sample holding mechanism used in an electron beam application device capable of effectively suppressing disturbance of an electric field due to existence of foreign matter. <P>SOLUTION: In this electron beam application device, the sample holding mechanism to hold the sample by applying a negative voltage to the sample has a support pedestal where the negative voltage is applied and which supports the sample from its lower part and a pressing part to press the sample from its upper part while the negative voltage is applied to the sample, and the pressing part is formed along the fringe part of the sample. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は、電子線応用装置に用いられる試料保持機構に関し、特に、試料に負の電圧を印加して、電子線の試料への到達エネルギーを減少させる電子線応用装置に用いられる試料保持機構に関する。 The present invention relates to a sample holding mechanism used in an electron beam application apparatus, and more particularly, to a sample holding mechanism used in an electron beam application apparatus that applies a negative voltage to a sample to reduce energy reaching the sample of the electron beam. .

荷電粒子線を用いて試料を加工する装置または試料の表面状態やパターン等を観察する装置においては、試料を保持する機構を有している。このような装置において、試料へのダメージやレジスト等の絶縁膜を有する試料が帯電を受けないように２ｋｅＶ以下の低加速電子線を照射している。一方で、対物レンズを通過する電子線の加速エネルギーが低くなると、空間電荷効果による収差が生じ、高分解能な観察が困難であった。 An apparatus for processing a sample using a charged particle beam or an apparatus for observing the surface state or pattern of the sample has a mechanism for holding the sample. In such an apparatus, a low-acceleration electron beam of 2 keV or less is irradiated so that the sample having an insulating film such as a resist or a resist is not charged. On the other hand, when the acceleration energy of the electron beam passing through the objective lens is lowered, aberration due to the space charge effect occurs, and high-resolution observation is difficult.

このような問題を効果的に解決するための手法としてリターディング技術がある。リターディング技術では、試料に負電圧を印加することによって、空間電荷効果による収差の抑制と、試料に到達する電子線の低加速化に基づくダメージ抑制の両立が可能となる。しかしながら、試料に印加される電圧によって形成される電界の作用により、試料端部での電界が乱され、その電界によって電子線が偏向を受けてしまうという問題がある。その結果、試料端部では、正確な測定や検査が困難であるという問題があった。このよう問題を解決するために、特許文献１，２，３、及び４に説明されているような技術がある。 There is a retarding technique as a method for effectively solving such a problem. In the retarding technique, by applying a negative voltage to the sample, it is possible to achieve both suppression of aberration due to the space charge effect and suppression of damage based on low acceleration of the electron beam reaching the sample. However, there is a problem that the electric field formed by the voltage applied to the sample disturbs the electric field at the end of the sample and the electron beam is deflected by the electric field. As a result, there is a problem that accurate measurement and inspection are difficult at the end of the sample. In order to solve such a problem, there are techniques as described in Patent Documents 1, 2, 3, and 4.

特許文献１，２，３、及び４には、リターディング電圧が印加された試料の周囲を包囲するように電極を配置し、当該電極にリターディング電圧と同じ電圧を印加する技術が説明されている。このような技術によれば、試料とその周囲との間に生じる段差に基づく電界の乱れを緩和し、試料の中心と同等の条件で、電子線を試料に入射させることが可能となる。 Patent Documents 1, 2, 3, and 4 describe a technique in which an electrode is disposed so as to surround the periphery of a sample to which a retarding voltage is applied, and the same voltage as the retarding voltage is applied to the electrode. Yes. According to such a technique, the disturbance of the electric field based on the step generated between the sample and the periphery thereof can be mitigated, and the electron beam can be incident on the sample under the same condition as the center of the sample.

特開２００４−７９５１６号公報JP 2004-79516 A 特開２００３−１１５２７４号公報JP 2003-115274 A 特開２０００−１４９８４５号公報JP 2000-149845 A 特開２０００−４０４８１号公報Japanese Patent Laid-Open No. 2000-40481

しかしながら、試料縁部付近の電界の乱れは、試料とその周囲との間の段差だけではなく、他の要因があることが、発明者らの検討により判明した。特に試料（例えば半導体ウェハ）の縁部周辺は、半導体プロセス時に、試料をピンセットで保持した際についた傷や、成膜，イオン打ち込み，エッチングなどの様々な工程にて用いられる、試料を保持する機構や加工の影響によって、土手状や谷状，線状や粉状の段差や異物が付着することがある。 However, the inventors have found that the disturbance of the electric field in the vicinity of the sample edge is caused not only by the step between the sample and its surroundings but also by other factors. In particular, the periphery of the edge of a sample (for example, a semiconductor wafer) holds the sample used in various processes such as scratches, film formation, ion implantation, etching, etc., when the sample is held with tweezers during a semiconductor process. Depending on the mechanism and processing, bank-like, valley-like, linear or powdery steps or foreign matter may adhere.

これら異物等は試料表面の電界を乱し、結果として電子線を偏向し、正確な検査や測定を阻害するという問題がある。特許文献１〜４に開示の技術では、異物等の存在に基づく電界の変動を抑制することは困難である。 These foreign substances or the like disturb the electric field on the sample surface, resulting in the problem of deflecting the electron beam and hindering accurate inspection and measurement. In the techniques disclosed in Patent Documents 1 to 4, it is difficult to suppress the fluctuation of the electric field based on the presence of foreign matter or the like.

以下に、異物等の存在による電界の乱れを効果的に抑制することが可能な電子線応用装置に用いられる試料保持機構について説明する。 Hereinafter, a sample holding mechanism used in an electron beam application apparatus capable of effectively suppressing disturbance of an electric field due to the presence of foreign matters and the like will be described.

上記目的を達成するための一態様として、電子線応用装置内にて、試料に負電圧を印加して試料を保持する試料保持機構において、負電圧が印加されると共に前記試料を下部から支持する支持台と、前記試料を上部から押圧する押圧部を有し、当該押圧部は前記試料の縁部に沿って形成されていると共に、前記負の電圧が印加されることを特徴とする試料保持機構を提案する。押圧部は、試料の縁部を上部から押圧するように形成されているため、試料の縁部近傍に存在する異物等を覆い、試料平面に形成される電位分布を平坦化することが可能になる。押圧部も厚みがあるため、厳密な意味での平坦化ではないが、押圧部の大きさは変化しないので、異物等の存在によらず、電位分布を所定の状態とすることができる。 As one mode for achieving the above object, in a sample holding mechanism for holding a sample by applying a negative voltage to the sample in the electron beam application apparatus, the negative voltage is applied and the sample is supported from below. A sample holder having a support base and a pressing portion for pressing the sample from above, the pressing portion being formed along an edge of the sample, and being applied with the negative voltage Propose mechanism. The pressing part is formed so as to press the edge of the sample from the top, so that it can cover the foreign matter existing near the edge of the sample and flatten the potential distribution formed on the sample plane. Become. Since the pressing portion is also thick, it is not flattening in a strict sense. However, since the size of the pressing portion does not change, the potential distribution can be set to a predetermined state regardless of the presence of foreign matter or the like.

上記一態様によれば、リターディング技術を採用した電子線応用装置において、試料上の異物等の存在によらず、安定した電位分布を形成することによる、測定，検査の高精度化を実現することが可能となる。 According to the above aspect, in the electron beam application apparatus adopting the retarding technique, high accuracy of measurement and inspection is realized by forming a stable potential distribution regardless of the presence of foreign matter or the like on the sample. It becomes possible.

以下図面を用いて、異物等の存在によらず、試料上に安定した電位分布を形成するための具体的な構成について、図面を用いて説明する。図１４は、電子線応用装置の一態様である走査電子顕微鏡の概略図である。なお、以下の説明は走査電子顕微鏡を例にとって説明するが、これに限られることはなく、電子線を試料に照射すると共に、試料に負電圧を印加して試料への到達エネルギーを低下させるいわゆるリターディング技術が採用される装置であれば、その種類は問わない。電子銃１０７から放出される一次電子ビーム１０６は、コンデンサレンズ１０５、及び対物レンズ１０２によって集束され、試料１１１に到達する。また、一次電子ビーム１０６は、偏向器１０３によって、試料上を一次元的、或いは二次元的に走査される。試料１１１は、保持機１１０上に配置され、保持機１１０は、図示しない移動機構を備えた試料ステージ１０１上に配置されている。試料ステージ１１０にはリターディング用電源１０４が接続されており、試料１０６に到達する一次電子ビーム１０６の到達エネルギー（加速電圧）は、その印加電圧によって調整される。 Hereinafter, a specific configuration for forming a stable potential distribution on a sample regardless of the presence of a foreign substance or the like will be described with reference to the drawings. FIG. 14 is a schematic diagram of a scanning electron microscope which is an embodiment of an electron beam application apparatus. The following description will be made by taking a scanning electron microscope as an example. However, the present invention is not limited to this. The sample is irradiated with an electron beam and a negative voltage is applied to the sample to reduce the energy reaching the sample. Any device can be used as long as the retarding technology is adopted. The primary electron beam 106 emitted from the electron gun 107 is focused by the condenser lens 105 and the objective lens 102 and reaches the sample 111. The primary electron beam 106 is scanned one-dimensionally or two-dimensionally on the sample by the deflector 103. The sample 111 is arranged on a holder 110, and the holder 110 is arranged on a sample stage 101 having a moving mechanism (not shown). A retarding power supply 104 is connected to the sample stage 110, and the energy (acceleration voltage) of the primary electron beam 106 that reaches the sample 106 is adjusted by the applied voltage.

試料の端部付近には試料プロセス時において、試料をピンセットで保持した際についたキズや、製膜・イオンインプラ，エッチングなど様々な装置で試料保持する機構や加工などの影響により、土手状や谷状，線状や粉状などの様々な段差や異物が付着することがある。図１５ａには、試料１の端部周辺であって試料１の上部に異物１１２が付着した状態が例示されている。 Near the edge of the sample, during the sample process, due to scratches when the sample is held with tweezers, the mechanism of holding the sample with various devices such as film formation, ion implantation, etching, etc. Various steps and foreign matters such as valleys, lines and powders may adhere. FIG. 15 a illustrates a state in which the foreign matter 112 is attached to the upper part of the sample 1 around the end of the sample 1.

ところで、リターディングによって試料の上方空間に電界が生ずるが、この生じた電界の概略を図１５ａに図示したような状態となる。リターディングによる電界は試料端部付近では試料１と保持機１１０との高さの差により、また、試料の端部付近には試料プロセス時において、試料をピンセットで保持した際についたキズや、製膜・イオンインプラ，エッチングなど様々な装置で試料保持する機構や加工などの影響により、土手状や谷状，線状や粉状などの様々な段差や異物１１２が付着している。これらの影響で当該電界１２０は端部付近では均一でなく乱れが生じている。その結果一次電子線１０６の軌道が不規則に曲げられるため、試料端部付近では正確な形状の評価などが困難であった。このような電界の乱れの影響はリターディングを採用した荷電粒子線装置であれば発生する可能性がある。また、上記のような荷電粒子線装置に試料を保持機に固定する方式が用いられているが、上記リターディングのため試料への電圧１０４の印加は、保持機１１０を介して行われている。 By the way, an electric field is generated in the upper space of the sample by the retarding, and an outline of the generated electric field is as shown in FIG. 15a. The electric field due to the retarding is caused by the difference in height between the sample 1 and the holder 110 near the end of the sample, and near the end of the sample, during the sample process, when the sample is held with tweezers, Various steps such as bank shape, valley shape, line shape, powder shape, and foreign matter 112 are attached due to the influence of the mechanism and processing for holding the sample with various apparatuses such as film forming, ion implantation, and etching. Due to these influences, the electric field 120 is not uniform in the vicinity of the end portion but is disturbed. As a result, since the trajectory of the primary electron beam 106 is irregularly bent, it is difficult to accurately evaluate the shape near the end of the sample. Such a disturbance of the electric field may occur in a charged particle beam apparatus employing retarding. In addition, a method of fixing the sample to the holder is used in the charged particle beam apparatus as described above, but the voltage 104 is applied to the sample through the holder 110 for the retarding. .

以下の説明では、保持機構を介して試料にリターディングのための電圧を印加することに着目し、上記事情を考慮してなされたものであって、試料プロセスによって生じた段差や異物などにより試料端部で発生する電界乱れを緩和できる機構について詳述する。 In the following description, focusing on applying a voltage for retarding to a sample through a holding mechanism, the above situation has been taken into consideration, and the sample is caused by a step or a foreign matter generated by the sample process. A mechanism that can alleviate the electric field disturbance generated at the end will be described in detail.

以下に、試料保持機構を真空中から脱着して多様式の試料を観察する電子線応用装置において、試料保持機構と試料とが同電位となるように構成され、試料を搭載する試料保持機構の高さを一定とした電極構造で、電極構造に試料端部を覆うためのひさし形状が有り、かつ電極構造高さと試料台底面部分に搭載された試料高さとが略平坦化となるよう試料台底面部が高さ方向に可動な機構について説明する。 In the electron beam application apparatus for observing various types of samples by detaching the sample holding mechanism from the vacuum, the sample holding mechanism and the sample are configured to have the same potential, and the sample holding mechanism for mounting the sample is described below. An electrode structure with a constant height, the electrode structure has an eaves shape to cover the end of the sample, and the sample stage so that the electrode structure height and the sample height mounted on the bottom of the sample stage are substantially flat A mechanism in which the bottom surface portion is movable in the height direction will be described.

なお、前記電極部分や前記試料底面部分は、取替えにより円盤，ウェハ，メディアディスク，角型試料など多様式の試料保持を可能とした構成としてもよい。なお、前記ひさし形状部分は、前記電極部分より着脱可能な構成としてもよい。なお、前記試料台底面側と前記試料台底面部分を支持する基底部分側との接続部分が逆ネジの関係となる機構を有し、搭載した試料が回転せずに高さ調整可能な構成としてもよい。なお、前記試料保持機構は、メディアディスク試料の加工・観察において、メディアディスクの中心側端部乃至外周側端部の少なくとも一方を覆うためのひさし形状を有する構成としてもよい。以下、具体的な実施態様を、図面を用いて説明する。 The electrode portion and the sample bottom surface portion may be configured to be capable of holding various types of samples such as a disk, a wafer, a media disk, and a square sample by replacement. The eaves-shaped portion may be configured to be detachable from the electrode portion. In addition, it has a mechanism in which the connection part between the sample stage bottom side and the base part side that supports the sample stage bottom part has a reverse screw relationship, and the mounted sample can be adjusted in height without rotating. Also good. The sample holding mechanism may have an eaves shape for covering at least one of the center side end portion and the outer peripheral side end portion of the media disc in processing and observation of the media disc sample. Hereinafter, specific embodiments will be described with reference to the drawings.

（実施例１）
図１と図１５に本発明の実施の形態である試料保持機の構成を示す。様々な試料サイズ（試料厚さ，大きさ）に対応するため、試料交換作業の効率化のために電極２の位置は試料１に関係なく試料ステージ１０１からの高さ固定とし、一方で試料保持機の試料台底面部４を上下動させて試料高さを調整可能とし、電極２の高さと試料１の高さとを略平坦化する機構を設け、さらに試料サイズ毎に当該リターディング電界のかかる電極２及び試料台底面部分４を取替え可能な構造とし、電極部分２にはひさし状の形状３を有した構成としてある。また、試料１を搭載する試料台底面部分４と電極部分２及びひさし状部分３は装置ステージ１０１０との接続台座を介して同電位となるようにしてある。ひさし状部分３の下部（試料１への接触部分）は、高さ調整機構ネジ部５によって、その高さが調整可能となっており、試料１を上方から押圧する押圧部として機能する。 Example 1
1 and 15 show the configuration of a sample holder which is an embodiment of the present invention. In order to cope with various sample sizes (sample thickness, size), the position of the electrode 2 is fixed to the height from the sample stage 101 regardless of the sample 1 in order to improve the efficiency of the sample exchange operation, while holding the sample. A sample height can be adjusted by moving the sample table bottom 4 of the machine up and down, a mechanism for substantially flattening the height of the electrode 2 and the height of the sample 1 is provided, and a retarding electric field is applied for each sample size. The structure is such that the electrode 2 and the sample base bottom portion 4 can be replaced, and the electrode portion 2 has an eave-like shape 3. Further, the sample table bottom surface portion 4 on which the sample 1 is mounted, the electrode portion 2 and the eaves-shaped portion 3 are set to the same potential via a connection base with the apparatus stage 1010. The lower part of the eaves-like part 3 (contact part to the sample 1) can be adjusted in height by a height adjusting mechanism screw part 5, and functions as a pressing part that presses the sample 1 from above.

電極２，ひさし部３，試料台底面部４等の試料保持機を構成する材料には、本実施例においてはＡｌを用いたが、他にＣ（グラファイト），Ｃｕ，Ｔａ，Ｍｏ，Ｔｉ，Ｗ，黄銅，青銅、及びこれら物質を含んだ化合物や合金等で電気導通性があり、非磁性体であるならば前記材料に対して特に限定するものではない。 In the present embodiment, Al is used as the material constituting the sample holder such as the electrode 2, the eaves portion 3, the sample table bottom surface portion 4, etc., but C (graphite), Cu, Ta, Mo, Ti, W, brass, bronze, and compounds and alloys containing these substances are electrically conductive, and are not particularly limited as long as they are non-magnetic.

様々なプロセスを経た後に試料を観察しようとする場合、試料１の端部付近には試料プロセス時において、試料をピンセットで保持した際についたキズや、製膜・イオンインプラ，エッチングなど様々な装置で試料保持する機構や加工などの影響により、土手状や谷状，線状や粉状などの様々な段差や異物１１２が付着しており端部付近は一様に平らでないことが多い。この様な試料を観察する場合、試料の端部付近では不均一に分布した異物１１２によりリターディング電界１２０の乱れが発生する部位が予想できず、一様になりづらいため端部付近での正確な観察・評価が困難であることが知られている。 When you want to observe the sample after going through various processes, near the edge of the sample 1, there are various devices such as scratches, film formation, ion implantation, etching, etc. In many cases, various steps such as a bank shape, a valley shape, a line shape, a powder shape, and the foreign matter 112 are attached due to an influence of a mechanism for holding the sample and processing, and the vicinity of the end portion is not uniformly flat. When observing such a sample, the region where the retarding electric field 120 is disturbed cannot be predicted due to the unevenly distributed foreign matter 112 in the vicinity of the end of the sample, and is difficult to be uniform. Is known to be difficult to observe and evaluate.

そのため本実施例では、試料端部を隠すためのひさし形状３を電極部分に試料と同心円になるよう試料端部付近をカバーし、当該リターディング電界１２０をひさし形状に起因した乱れにのみ限定することで、乱れた領域を低減できる構成とした。このひさし形状３に関して、プロセス等によって生じた端部付近での形状乱れによるリターディング電界１２０への影響を少なくするための形状であれば当該ひさし部分の開口形状を限定するものではない。ひさし部３の厚みは、厚くすると試料面と電極面との段差が大きくなり、当該リターディング電界１２０の乱れは大きくなってしまうためできるだけ薄くした方が良いが、薄くした場合に試料に押し当てられると、ひさし部分の変形により電界の乱れがひさし部分で緩和できずに影響を与えてしまう可能性がある。発明者らの実験では観察するウェハ外周部でのリターディング電界の乱れを小さくなるためには、当該ひさし部の厚みを０.０５mm以上で０.３mm以下とするのが電界の乱れを小さくするためにはよいことが確認されているが、リターディング電界の影響を少なくするためであれば当該厚みを前記範囲に特に限定するものではない。また、ひさし部３の幅は試料外周でのリターディング電界の乱れた領域をカバーすることができればよく、少なくとも１mmあれば外周部での電界の乱れが小さくなることを確認したが、プロセスによっては段差や異物１１２が存在する領域は様々であるため、リターディング電界１２０の乱れた領域をカバーすることができる形状であるならば当該幅を限定するものではない。 Therefore, in this embodiment, the eaves shape 3 for concealing the end of the sample is covered with the electrode portion in the vicinity of the sample end so as to be concentric with the sample, and the retarding electric field 120 is limited only to the disturbance caused by the eaves shape. Thus, the configuration is such that the disturbed area can be reduced. As for the eaves shape 3, the shape of the opening of the eaves portion is not limited as long as it is a shape for reducing the influence on the retarding electric field 120 due to the shape disturbance in the vicinity of the end portion caused by the process or the like. As the thickness of the eaves portion 3 increases, the step between the sample surface and the electrode surface increases, and the disturbance of the retarding electric field 120 increases, so it is better to make it as thin as possible. If this occurs, there is a possibility that the disturbance of the electric field is affected by the deformation of the eaves part, which cannot be relaxed in the eaves part. In the experiments of the inventors, in order to reduce the disturbance of the retarding electric field at the outer periphery of the wafer to be observed, the thickness of the eaves portion is set to 0.05 mm or more and 0.3 mm or less to reduce the electric field disturbance. In order to reduce the influence of the retarding electric field, the thickness is not particularly limited to the above range. Further, the width of the eaves portion 3 is only required to cover the region where the retarding electric field is disturbed at the outer periphery of the sample. It has been confirmed that the disturbance of the electric field at the outer periphery becomes small if it is at least 1 mm. Since there are various regions where the step and the foreign matter 112 exist, the width is not limited as long as the shape can cover the region where the retarding electric field 120 is disturbed.

また図３に示すように、電極部分の最上層２ｄを着脱可能な構造として試料を電極部下層部分２ｃに載せる作業を簡便に行える構造としてあってもよい。図３（ａ）は、電極上層２ｄから電極下層２ｃ側を貫通した足部１０の先端にネジ山を形成し、３箇所（１２０度ピッチ）それぞれを裏面側からナット１１で止め、電極上層部分２ｃを固定した状態であるが、この上層部分２ｃが試料保持機取り扱い時に動いたり落下したりする恐れのない場合にはそのまま電極下層部分２ｃに載せただけとしてもよく、また、上層部２ｄと電極下層側２ｃとが滑りにくくなる様に抵抗を増やすように梨地加工やサンドブラスト加工部を設けて動きを抑止する構造としてもよい。 Further, as shown in FIG. 3, the uppermost layer 2d of the electrode part may be detachable so that the work of placing the sample on the electrode lower layer part 2c can be easily performed. FIG. 3A shows a screw thread formed at the tip of the foot 10 penetrating from the electrode upper layer 2d to the electrode lower layer 2c side, and each of three locations (120-degree pitch) is fastened with a nut 11 from the back surface side. 2c is fixed, but when there is no fear that the upper layer portion 2c moves or falls during handling of the sample holder, it may be placed on the electrode lower layer portion 2c as it is. It is good also as a structure which suppresses a motion by providing a satin processing or a sandblasting part so that resistance may be increased so that it may become difficult to slip on the electrode lower layer side 2c.

さらに、固定する方法として、前述した電極裏面側（下層側）からナット止めや、ネジ止めによる固定、電極上層部分２ｄに設けた平板付き足部１２を下層部分２ｃとの間で回転させて固定（図３（ｂ））、前記足部をＴ字やＹ字型等として固定する方法、あるいは、上層部分２ｄを上面側から前記ネジやナットなどで固定する方式や、電極上層２ｄ・下層２ｃ部分に溝１３を切ってはめ合いとして上層部分２ｄを載せる方式（図３（ｃ））、上層側電極部分２ｄが下層側２ｃよりも直径が大きく、上層側の側面部分よりネジを用いて下層側と締め付ける方式としてあってもよい。動きを防止するために用いる固定部分は少なくとも一箇所以上設けてあればよく、上層側電極部分２ｄと下層側電極部分２ｃとの接続方法に関して前記固定方式の組み合わせであってもよく、固定方式を特に限定するものではない。 Furthermore, as a method of fixing, fixing with a nut or screwing from the electrode back side (lower layer side) described above, and fixing by rotating the flat foot 12 provided on the electrode upper layer portion 2d with the lower layer portion 2c. (FIG. 3B), a method of fixing the foot portion as a T-shape or a Y-shape, or a method of fixing the upper layer portion 2d from the upper surface side with the screws or nuts, or an electrode upper layer 2d / lower layer 2c. A method in which an upper layer portion 2d is placed as a fit by cutting a groove 13 in the portion (FIG. 3C), the upper layer side electrode portion 2d is larger in diameter than the lower layer side 2c, and a lower layer using screws from the side portion on the upper layer side There may be a method of tightening with the side. It is sufficient that at least one or more fixing portions used for preventing movement are provided, and a combination of the above-described fixing methods may be used for the connection method of the upper layer side electrode portion 2d and the lower layer side electrode portion 2c. There is no particular limitation.

試料保持機の試料サイズは、０.５インチ，０.８５インチ，２５mm，１インチ，１.２５インチ，１.３インチ，１.５インチ，１.８インチ，１.８９インチ，５０mm，２インチ，２.５インチ，６５mm，７０mm，７５mm，３インチ，３.３インチ，３.５インチ，１００mm，４インチ，１２５mm、５インチ，１５０mm，６インチ，２００mm，８インチ，３００mm，１２インチ等各サイズのウェハやディスク等の様々なサイズに対応することができる。但し試料保持機の試料サイズに関して前記大きさに特に限定するものではない。試料ステージとの台座と接続された電極部分２と、各電極サイズに合わせた試料台底面部分４とを変えることで様々な試料サイズに対応する（図示せず）。電極部分２には試料形状と同じ大きさの開口があり、前記開口上部に前記ひさし形状３を形成してある。電極部分外周サイズは試料サイズ以上の大きさのもので、観察用試料室に入る大きさであるならばいくらでもよいが、発明者らの実験によれば電極部分の形状が少なくとも５mm以上試料サイズより大きい場合には、試料外周部付近でのリターディング電界の歪みが小さくなることを確認しているが、前記サイズに限定するものではない。試料台底面部分４の直径は、取り付ける試料のサイズよりも大きければよく特に限定するものではない。 Sample sizes of the sample holder are 0.5 inch, 0.85 inch, 25 mm, 1 inch, 1.25 inch, 1.3 inch, 1.5 inch, 1.8 inch, 1.89 inch, 50 mm, 2 inch, 2.5 inch, 65 mm, 70 mm, 75 mm, 3 inch, 3.3 inch, 3.5 inch, 100 mm, 4 inch, 125 mm, 5 inch, 150 mm, 6 inch, 200 mm, 8 inch, 300 mm, 12 Various sizes of wafers and disks of various sizes such as inches can be accommodated. However, the sample size of the sample holder is not particularly limited to the above size. Various sample sizes can be accommodated by changing the electrode part 2 connected to the pedestal with the sample stage and the sample base bottom part 4 according to each electrode size (not shown). The electrode portion 2 has an opening having the same size as the sample shape, and the eaves shape 3 is formed above the opening. The electrode part outer periphery size is larger than the sample size and may be any size as long as it can fit into the observation sample chamber. However, according to the experiments by the inventors, the shape of the electrode part is at least 5 mm or more than the sample size. When it is large, it has been confirmed that the distortion of the retarding electric field in the vicinity of the outer periphery of the sample is small, but the size is not limited to the above. The diameter of the sample stage bottom surface portion 4 is not particularly limited as long as it is larger than the size of the sample to be attached.

本実施例での試料の高さ調整機構には、試料台底面部側壁にネジ山加工５ａをして電極部分にそれに対応するネジ山を形成することで可能な構造とした。ネジ山のピッチは高さ調整のためであるので余り大きくすると調整が難しくなる。本実施例では１回転で１mm上下する構造としたがピッチはそれ以上でも以下でも良く、高さ調節のためであるならばピッチを限定するものではない。試料台底面最下部には回転を容易にするためにネジ山のない円盤状構造としサイズを回転させる円筒よりも大きくしたが、この部分に関しては回転を容易にするため外周部にローレット４ａやナーリング加工をしたり、プラスやマイナス，ヘックス型のドライバ等を使用するための溝を形成したり、あるいは、レンチを使用するための六角穴や四角あるいは六角形のボルト形状にしてあってもよく、また最下部までネジ山が切ってある構造や、最下部のサイズが試料台底面部の円筒と同じかそれより小さくなっていてもよく、回転調整を容易に行うための形状を特に限定するものはない。また、試料台底面部分の高さ調節機構が調整後に動かないようダブルナット構造となる回転防止用板６を用いてあってもよく（図４）、高さ調整するための部分の構成を特に限定するものではない。 The sample height adjusting mechanism in the present embodiment has a structure that can be formed by forming a thread 5a on the side wall of the bottom surface of the sample table and forming a corresponding thread on the electrode portion. Since the thread pitch is for height adjustment, if it is too large, adjustment becomes difficult. In this embodiment, it is structured to move up and down by 1 mm in one rotation, but the pitch may be more or less, and the pitch is not limited as long as it is for height adjustment. The bottom of the sample stage has a disk-like structure with no threads to facilitate rotation, and the size is larger than that of the rotating cylinder. However, this part has a knurling 4a and knurling on the outer periphery to facilitate rotation. You may process it, form a groove to use a plus, minus, hex type screwdriver, etc., or make it a hexagonal hole, square or hexagonal bolt shape for using a wrench, In addition, the structure where the thread is cut to the bottom, the size of the bottom may be the same as or smaller than the cylinder on the bottom of the sample stage, and the shape for easy rotation adjustment is particularly limited There is no. Further, an anti-rotation plate 6 having a double nut structure may be used so that the height adjusting mechanism of the bottom surface portion of the sample stage does not move after adjustment (FIG. 4), and the configuration of the portion for adjusting the height is particularly preferred. It is not limited.

試料１として厚さ０.４mmの３インチ直径のＳｉディスク基板を用い、この高さ調整機構を利用して目視による試料１の上部と電極２のひさし部分３とが略平坦化するよう高さ調整した上で走査電子顕微鏡等に入れて観察を行った。電極形状２は直径４インチで中央に該基板を入れる３インチ分の穴が有り、ひさし部分３の厚みは０.２mmとし幅は１mmとし、試料台底面４の形状は直径３インチの物で、図３（ｃ）記載の電極上層部分をはめあいで着脱する形態のものを用いた。その結果、本発明の方式を取らずにウェハを観察した場合と比較実験した結果、少なくとも直径で７mm分リターディング電界による乱れた領域を減らすことができた。これにより電極表面と試料表面とを略平坦化しひさしを設けた構造の効果が確認できた。 Using a Si disk substrate having a thickness of 0.4 mm as the sample 1 and using this height adjustment mechanism, the height of the upper part of the sample 1 and the eaves portion 3 of the electrode 2 are visually flattened. After adjustment, the sample was placed in a scanning electron microscope or the like and observed. The electrode shape 2 has a diameter of 4 inches, a hole for 3 inches to put the substrate in the center, the thickness of the eaves portion 3 is 0.2 mm, the width is 1 mm, and the shape of the sample table bottom surface 4 is 3 inches in diameter. 3 (c) was used to attach and detach the electrode upper layer part by fitting. As a result, as a result of comparison experiments with the case of observing the wafer without adopting the method of the present invention, it was possible to reduce the disordered region due to the retarding electric field by at least 7 mm in diameter. As a result, the effect of the structure in which the electrode surface and the sample surface were substantially flattened and provided with eaves was confirmed.

（変形例１−１）
ウェハ試料においてはオリフラ１ａやサブオリフラ１ｂ，ノッチオリフラなど円形形状が一様でない試料もあり、この一様でない形状部分による電界乱れもひさし形状により抑えることができる。本変形例では、実施例１に基づいてひさし形状を電極部分に形成した。実施の形態を図５に示す。電極部分２にはウェハオリフラ１ａに合わせた形状を加え、試料の回転を抑止して高さ調整に対応できる。電極部分に形成したウェハオリフラ対応部は、高さ調整による試料底面部分４の上下動を制限しない形とする必要性がある。そのため、本変形例ではひさし部分３の下部に厚さ０.２mmでオリフラ形状１ａに合わせた段差２ｂを設けたが、この厚みは観察するウェハ１の厚みが一定の物を観察する場合にはウェハ厚みと同じかそれよりも薄いのであればよく、ウェハ部分の形状に対応している物であるならば、前記厚みに限定するものではない。ひさし部分３は、ウェハ試料におけるオリフラ部分及び外周部でのプロセス影響を隠すため、ひさし３の形状は、開口形状をウェハ試料と相似形で小さくしたものや、ウェハ試料のオリフラ部分を隠せる幅で開口形状を円形としたものであってもよく、プロセスによるリターディング電界への影響を少なくするための形状であれば当該ひさし部分の開口形状を限定するものではない。 (Modification 1-1)
Some wafer samples have a non-uniform circular shape such as the orientation flat 1a, the sub orientation flat 1b, and the notch orientation flat, and the electric field disturbance due to the non-uniform shape can be suppressed by the eaves shape. In this modification, an eaves shape is formed in the electrode portion based on the first embodiment. An embodiment is shown in FIG. A shape matched to the wafer orientation flat 1a can be added to the electrode portion 2 to suppress the rotation of the sample and cope with height adjustment. The wafer orientation flat corresponding part formed in the electrode part needs to be a shape which does not restrict | limit the vertical movement of the sample bottom face part 4 by height adjustment. Therefore, in this modification, a step 2b having a thickness of 0.2 mm and matching with the orientation flat shape 1a is provided below the eaves portion 3, but this thickness is used when observing an object with a constant thickness of the wafer 1 to be observed. The thickness may be the same as or thinner than the wafer thickness, and is not limited to the thickness as long as it corresponds to the shape of the wafer portion. Since the eaves portion 3 conceals the influence of the process at the orientation flat portion and the outer peripheral portion of the wafer sample, the shape of the eaves 3 is such that the opening shape is similar to that of the wafer sample and the width that can hide the orientation flat portion of the wafer sample. The opening shape may be circular, and the opening shape of the eaves portion is not limited as long as it is a shape for reducing the influence of the process on the retarding electric field.

試料として厚さ０.６mmの３インチＳｉウェハ基板を用い、この高さ調整機構を利用して目視による試料上部とひさし部分との高さを略平坦化した上で走査電子顕微鏡等に入れて観察を行った。電極形状は直径４インチで中央に該基板を入れる３インチ分の穴が有り、ひさし部分の厚みを０.２mmとし幅を２mmとし、ひさし下部にオリフラ形状に合わせた段差０.２mmのウェハ回転防止部を形成し、試料台底面形状は直径３インチの物を用いた。その結果、本発明の方式を取らずにウェハを観察した場合と比較実験した結果、少なくとも直径で５mm分リターディング電界による乱れた領域を減らすことができた。これにより電極表面と試料表面とを略平坦化しひさしを設けた構造の効果が確認できた。 A 3 mm Si wafer substrate with a thickness of 0.6 mm is used as a sample. The height adjustment mechanism is used to flatten the height of the sample upper part and the eaves part and put it in a scanning electron microscope or the like. Observations were made. The electrode shape is 4 inches in diameter, with a 3 inch hole in the center to insert the substrate, the thickness of the eaves part is 0.2 mm, the width is 2 mm, and the wafer is rotated by a step of 0.2 mm according to the orientation flat at the bottom of the eaves A prevention part was formed, and a sample table having a bottom surface shape of 3 inches in diameter was used. As a result, as a result of a comparison experiment with the case of observing the wafer without adopting the method of the present invention, it was possible to reduce the disordered region due to the retarding electric field by at least 5 mm in diameter. As a result, the effect of the structure in which the electrode surface and the sample surface were substantially flattened and provided with eaves was confirmed.

（変形例１−２）
実施の形態を図６に示す。試料保持機の試料サイズは、０.５インチ，０.８５インチ，１インチ，１.２５インチ，１.３インチ，１.５インチ，１.８インチ，１.８９インチ，２インチ，２.５インチ，６５mm，７０mm，３インチ，８０mm，３.３インチ，３.５インチ，４インチ，１２０mm，５インチ，２００mm，８インチ等試料中心に穴のある円盤状メディアディスクの様々なサイズに対応することができる。但し試料保持機の試料サイズに関して前記大きさに特に限定するものではない。電極部分２には試料形状と同じ大きさの開口があり、最上層部に前記ひさし形状３を形成してある。外周部分サイズはそれ以上の大きさのもので、観察用試料室に入る大きさであるならばいくらでもよいが、発明者らの実験によれば電極部分の形状が少なくとも５mm以上試料サイズより大きい場合には、試料外周部付近でのリターディング電界の歪みが小さくなることを確認しているが前記サイズに特に限定するものではない。なお、試料台底面形状４の直径は前記大きさに限定するものではなく、試料サイズより大きければいくらでもよい。 (Modification 1-2)
An embodiment is shown in FIG. Sample sizes of the sample holder are 0.5 inch, 0.85 inch, 1 inch, 1.25 inch, 1.3 inch, 1.5 inch, 1.8 inch, 1.89 inch, 2 inch, 2 Various sizes of disc-shaped media discs with holes in the sample center, such as .5 inch, 65 mm, 70 mm, 3 inch, 80 mm, 3.3 inch, 3.5 inch, 4 inch, 120 mm, 5 inch, 200 mm, 8 inch It can correspond to. However, the sample size of the sample holder is not particularly limited to the above size. The electrode portion 2 has an opening having the same size as the sample shape, and the eaves shape 3 is formed in the uppermost layer portion. The outer peripheral part size is larger than that and may be any size as long as it can fit into the observation sample chamber. However, according to the experiments conducted by the inventors, the electrode part has a shape larger than the sample size by at least 5 mm. Although it has been confirmed that the distortion of the retarding electric field in the vicinity of the outer periphery of the sample is small, the size is not particularly limited. Note that the diameter of the sample stage bottom surface shape 4 is not limited to the above-described size, and may be any as long as it is larger than the sample size.

試料台底面部分４の形状は、メディアディスク中心の穴と同等サイズで高さが試料厚さと同じになるよう同じ厚みの円盤３ａを中心に設置したり、試料台底面の中心部分を前記試料台底面部分４の可動方式同様に上下できる構造を追加したりすることで、中心部分と試料とが略平坦化する形態としてあってもよく、試料外周側の電極部分２に実施例１記載のひさし３のみを設け試料中心付近に円盤などを何も設置しない構造や（図６（ａ））、試料外周側の電極部分２に実施例１記載のひさし３を設けた構造や（図６（ｂ））、試料作製時メディアディスクの場合には中心部分を保持してプロセスを行ったりする工程により中心側に段差が存在する。この場合には、中心に設置する電極材３ａに試料高さと同じ厚みの上部にひさし部分３ｂを形成した円盤とし、試料外周部分はプロセスの影響による段差や異物によるリターディング影響が無視できる場合には外周側電極部分２のひさし形状は無くてもよいし（図６（ｃ））、または中心部分と外周部分の電極どちらにもひさしを設けてある構造としてあってもよく（図６（ｄ））、プロセスなどの影響によって基板端部側での段差や異物からの当該リターディング影響を軽減する構造であるならば、特に形状を限定するものではない。 The shape of the bottom surface portion 4 of the sample stage is set around a disk 3a having the same size as the hole in the center of the media disk and the same thickness as the thickness of the sample. The center portion and the sample may be substantially flattened by adding a structure that can move up and down in the same manner as the movable method of the bottom surface portion 4, and the eaves described in the first embodiment are formed on the electrode portion 2 on the outer periphery side of the sample. Or a structure in which no disc or the like is provided near the center of the sample (FIG. 6A), a structure in which the eaves 3 described in Example 1 is provided on the electrode portion 2 on the outer periphery of the sample (FIG. 6B )) In the case of a media disk at the time of sample preparation, there is a step on the center side due to the process of holding the center portion and performing the process. In this case, the electrode material 3a installed at the center is a disk in which an eaves portion 3b is formed on the upper part of the same thickness as the sample height, and the sample outer peripheral portion has a step difference caused by the process and a retarding effect due to foreign matter can be ignored. May not have the eaves shape of the outer peripheral side electrode portion 2 (FIG. 6C), or may have a structure in which eaves are provided on both the central portion and the outer peripheral portion of the electrode (FIG. 6D). )), The shape is not particularly limited as long as it has a structure that reduces the effect of retarding from a step or foreign matter on the substrate end side due to the influence of the process.

中心部分での電極材２ａにひさし３ｂを設ける場合には、円盤２ａの底面が試料台底面部分４と電気的に接触するように厚みを試料ごとに合うよう作製して設置する形状や、ひさしを設けた中心部分を試料設置後に取り付け、実施例１記載の試料台底面４の可動部同様に上下できる構造として試料に合わせて高さを調整する構造を追加してあってもよく、プロセスによるリターディング電界への影響を少なくするための形状であれば、中心部分の電極構造の有無や形状，取り付け方及び試料外周側に設置するひさしの厚みや幅を実施例１に記載のひさし形状サイズや本変形例記載の数値範囲に限定するものではない。 When the eaves 3b is provided in the electrode material 2a in the center portion, the shape and the elongate shape are prepared so that the thickness of each disc 2a is adjusted to match the sample such that the bottom surface of the disk 2a is in electrical contact with the sample table bottom surface portion The center part provided with the sample may be attached after the sample is installed, and a structure that adjusts the height according to the sample may be added as a structure that can be moved up and down like the movable part of the sample table bottom surface 4 described in Example 1. If the shape is to reduce the influence on the retarding electric field, the presence / absence and shape of the electrode structure in the central portion, the attachment method, and the thickness and width of the eaves installed on the outer periphery side of the sample are the eave shape sizes described in the first embodiment. It is not limited to the numerical ranges described in this modification.

図６（ｄ）の断面形状で一番右側に記載した形態の中心部分の電極構造を用い、試料として厚さ０.８mmで２.５インチハードディスク用アルミニウムディスク基板を用い、外周側に厚みが０.２mmで幅１mmのひさし３を設けた電極構造を有して高さ調整機構を利用して目視による試料上部と電極２との高さを略平坦化した。さらに、中心に設置した電極２ａ形状はメディアディスク１に合わせてひさし無し部の直径が２５mmの円筒で、ひさし部分３ａは外周側と同じく厚みが０.２mmで幅１mmとした。この中心部分２ａも試料１と略平坦化した上で試料保持機構を走査電子顕微鏡等に入れて観察を行った。電極形状は直径４インチで中央に該２.５インチ基板に合わせた穴が有り、試料台底面形状４は基板サイズと同じ物を用いた。その結果、本発明の方式を取らずにディスクを観察した場合と比較して、少なくとも試料外周側では直径で３mm分、内周側では直径で２mm分リターディング電界の乱れた領域を減らすことができた。これにより電極表面と試料表面とを略平坦化しひさしを設けた構造の効果が確認できた。 Using the electrode structure of the central portion of the form described on the rightmost side in the cross-sectional shape of FIG. 6D, using a 2.5-inch aluminum disk substrate for a hard disk with a thickness of 0.8 mm as the sample, the thickness is on the outer peripheral side. The height of the upper part of the sample and the electrode 2 was visually flattened by using a height adjusting mechanism having an electrode structure provided with an eaves 3 having a width of 0.2 mm and a width of 1 mm. Further, the shape of the electrode 2a installed at the center is a cylinder with a diameter of 25 mm corresponding to the media disk 1, and the eaves portion 3a has a thickness of 0.2 mm and a width of 1 mm as in the outer peripheral side. The central portion 2a was also substantially flattened with the sample 1, and the sample holding mechanism was put into a scanning electron microscope or the like for observation. The electrode shape was 4 inches in diameter with a hole aligned with the 2.5 inch substrate in the center, and the sample base bottom surface shape 4 was the same as the substrate size. As a result, compared with the case where the disk is observed without taking the method of the present invention, the area where the retarding electric field is disturbed can be reduced by at least 3 mm in diameter on the outer circumference side and 2 mm on the inner circumference side. did it. As a result, the effect of the structure in which the electrode surface and the sample surface were substantially flattened and provided with eaves was confirmed.

（変形例１−３）
図７に実施の形態を示す。１０mm角，１５mm角，２０mm角，２５mm角，３０mm角，５０mm角，７５mm角，３インチ角，１００mm角，４インチ角，１２５mm角，５インチ角，１５０mm角，６インチ角，７インチ角，２００mm角，８インチ角、等の角型試料等様々なサイズに対応することができる。但し試料保持機の試料サイズに関して前記大きさに特に限定するものではなく、正方形形状に限らず長方形形状であってもよい。試料台底面４の形状は試料サイズの対角線長さ以上となるように、例えば前記試料サイズに対応するとそれぞれ１５mm，２２mm，２９mm，３６mm，４３mm，７１mm，１０７mm，４.３インチ，１４２mm，５.７インチ，１７７mm，２１３mm，７.１インチ，８.５インチ，９.９インチ，２８３mm，１１.４インチとし、電極部分２には該試料形状と同じ大きさの開口があり、最上層部に前記ひさし形状３を形成してある。電極部分外周の形状は試料サイズと相似形や円形形状でサイズがそれ以上の大きさのもので、観察用試料室に入る大きさであるならばいくらでもよく、この形状を前記形状に限定するものではない。発明者らの実験によれば電極部分の形状が試料サイズより少なくとも５mm以上大きい場合には、試料外周部付近でのリターディング電界の歪みが小さくなることを確認しているが、前記大きさに限定するものではない。また、電極部分２には角型試料に合わせた形状２ｂをひさし３下部に設け、試料の回転を抑止して高さ調整に対応できる。電極部分２に形成した角型試料に合わせた形状２ｂは、高さ調整による試料底面部分４の上下動を制限しない形とする必要性があるため、本変形例ではひさし部分３の下部に厚さ０.２mmで角型試料に合わせた段差２ｂを設けたが、この厚みは観察するウェハの厚みが一定の物を観察する場合にはウェハ厚みと同じかそれ以下であればよく、前記厚みに限定するものではない。なお、試料台底面円柱４形状の直径は前記大きさに限定するものではなく、試料対角線サイズより大きければいくらでもよい。 (Modification 1-3)
FIG. 7 shows an embodiment. 10 mm square, 15 mm square, 20 mm square, 25 mm square, 30 mm square, 50 mm square, 75 mm square, 3 inch square, 100 mm square, 4 inch square, 125 mm square, 5 inch square, 150 mm square, 6 inch square, 7 inch square, Various sizes such as square samples of 200 mm square, 8 inch square, etc. can be supported. However, the sample size of the sample holder is not particularly limited to the above-described size, and is not limited to a square shape but may be a rectangular shape. The shape of the sample table bottom surface 4 is not less than the diagonal length of the sample size. For example, 15 mm, 22 mm, 29 mm, 36 mm, 43 mm, 71 mm, 107 mm, 4.3 inch, 142 mm, and 5. 7 inch, 177 mm, 213 mm, 7.1 inch, 8.5 inch, 9.9 inch, 283 mm, 11.4 inch, and electrode part 2 has an opening of the same size as the sample shape, and the top layer The eaves shape 3 is formed on the surface. The shape of the outer periphery of the electrode part is similar to the sample size or circular shape, and the size is larger than that, and any size can be used as long as it can fit into the sample chamber for observation, and this shape is limited to the above shape. is not. According to the experiments by the inventors, it has been confirmed that when the shape of the electrode portion is at least 5 mm larger than the sample size, the distortion of the retarding electric field near the outer periphery of the sample is reduced. It is not limited. In addition, the electrode portion 2 is provided with a shape 2b corresponding to the square sample at the lower portion of the plate 3 so that the rotation of the sample can be suppressed and the height can be adjusted. Since the shape 2b according to the square sample formed on the electrode portion 2 needs to be a shape that does not restrict the vertical movement of the sample bottom surface portion 4 by height adjustment, the thickness 2b is formed below the eaves portion 3 in this modification. The step 2b is provided with a thickness of 0.2 mm and matched to the square sample, but this thickness may be equal to or less than the wafer thickness when observing a constant wafer thickness. It is not limited to. Note that the diameter of the shape of the sample table bottom surface column 4 is not limited to the above-mentioned size, and may be any as long as it is larger than the sample diagonal size.

角型試料には、試料外周部にプロセスによる段差や異物の付着以外にも、当該試料サイズに切り出す際の切削傷や破片付着による段差も存在しているので、本発明の方式を採用しない場合と比較してひさしを加えた効果は大きい。試料として厚さ０.８mmの５０mm角Ｓｉ基板を用い、この高さ調整機構を利用して略平坦化した上で走査電子顕微鏡等に入れて観察を行った。電極形状は直径４インチで中央に該基板を入れる５０mm角分の穴が有り、試料台底面形状は直径３インチの物を用いた。ひさしの幅を２mmとして、厚みを０.２mmとし、本発明の方式を取らずに角形基板を観察した場合と比較して、少なくとも８mm分リターディング電界による乱れた領域を減らすことができた。これにより電極表面と試料表面とを略平坦化しひさしを設けた構造の効果が確認できた。 In addition to the steps and foreign matter attached to the outer periphery of the sample, there are also steps due to cutting flaws and debris attached to the sample size. Compared with, the effect of adding eaves is great. A 50 mm square Si substrate having a thickness of 0.8 mm was used as a sample, and the surface was flattened using this height adjusting mechanism, and then placed in a scanning electron microscope or the like for observation. The electrode shape was 4 inches in diameter with a 50 mm square hole in the center for the substrate, and the sample base bottom shape was 3 inches in diameter. Compared to the case where the width of the eaves is set to 2 mm and the thickness is set to 0.2 mm, and the square substrate is observed without taking the method of the present invention, the region disturbed by the retarding electric field can be reduced by at least 8 mm. As a result, the effect of the structure in which the electrode surface and the sample surface were substantially flattened and provided with eaves was confirmed.

（実施例２）
実施例１同様のひさしを設けた電極部分２と試料を載せる試料台底面部分４とで構成されているが、図８に示すように試料台底面部分４に棒形状を形成しその部分にネジ５ａが切ってある。この棒部分は試料台底面部４と同一構造や、試料台底面部分にねじ込む構造としてあってもよく、高さ調整機構として働く機能を有していればよく形状や接続方法を限定する物ではない。そして、本実施例においてはステージと接続する台座部分を基底部分７として試料台底面部分のネジ５ａと合うネジ溝を基底部７に作製して、基底部分７と試料台底面下部の棒部分５ａとの間で高さ調節機構を形成したが、基底部分７を電極部分２から延長された部分に形成してあってもよく、高さ調節用のネジ溝が切ってあれば基底部分７の形成された部位を特定するものではない。この場合にも実施例１と同じくリターディング電界の乱れた領域を低減することができ、電極表面と試料表面とを略平坦化しひさしを設けた構造の効果が確認できた。 (Example 2)
The electrode portion 2 is provided with the same eaves as in the first embodiment, and the sample table bottom surface portion 4 on which the sample is placed. As shown in FIG. 8, a rod shape is formed on the sample table bottom surface portion 4 and a screw is formed on that portion. 5a is cut. This bar portion may be the same structure as the sample table bottom surface portion 4 or a structure screwed into the sample table bottom surface portion, and may have a function that functions as a height adjusting mechanism, and the shape and connection method are limited. Absent. In this embodiment, the base portion 7 is used as a base portion to be connected to the stage, and a screw groove is formed in the base portion 7 so as to match the screw 5a at the bottom surface portion of the sample base. However, the base portion 7 may be formed in a portion extended from the electrode portion 2, and if the height adjusting screw groove is cut, the base portion 7 It does not specify the formed site. Also in this case, the region in which the retarding electric field was disturbed could be reduced as in Example 1, and the effect of the structure in which the electrode surface and the sample surface were substantially flattened and provided with eaves could be confirmed.

（実施例３）
実施例２同様の構成であるが、図９に示した形態のようにネジきりした部分が棒状部分の全てでなく、ネジ部５ａと支え部５ｂとで構成されていてもよい。この場合にも実施例１と同じくリターディング電界の乱れた領域を低減することができ、電極表面と試料表面とを略平坦化しひさしを設けた構造の効果が確認できた。 (Example 3)
Although it is the structure similar to Example 2, as shown in the form shown in FIG. 9, the part which was screwed may be comprised by the screw part 5a and the support part 5b instead of all the rod-shaped parts. Also in this case, the region in which the retarding electric field was disturbed could be reduced as in Example 1, and the effect of the structure in which the electrode surface and the sample surface were substantially flattened and provided with eaves could be confirmed.

（実施例４）
実施例２と同様に試料台底面部分４と基底部分７との間を棒状パーツで接続しているが、本実施例の形状は図１０に示すように、試料台底面部分４にもネジきりをし、基底部分７とは逆廻しネジの関係にしてある。この構成にすることで、棒状パーツを回転させて高さ調節を実施した場合に、試料台底面部分４が回転することなく高さ調整することができる。試料台は真空中で使用するため、試料台底面側のネジきり部分５ｃを真空引きするために棒状パーツ中心に貫通穴を開けたり、ネジ切りした部分の一部部分を削り落としたりしてあってもよく、特にネジ部分を真空対応とした加工の有無に限定するものではなく、高さ調節ができる構造であればよい。また、本実施例ではネジ部５ａと逆ネジ部５ｃとの間に支え部５ｂを設けたが、支え部５ｂが無い構成としてあってもよく、支え部５ｂの有無に関して特に限定する物ではない。 Example 4
Similar to the second embodiment, the sample base bottom surface portion 4 and the base portion 7 are connected by a bar-shaped part. However, the shape of this embodiment is also twisted on the sample base bottom surface portion 4 as shown in FIG. The base portion 7 is in a reverse screw relationship. With this configuration, when the height is adjusted by rotating the rod-shaped part, the height can be adjusted without rotating the sample stage bottom surface portion 4. Since the sample stage is used in a vacuum, a through hole is made in the center of the bar-shaped part in order to evacuate the threaded part 5c on the bottom side of the sample stage, or a part of the threaded part is scraped off. In particular, the present invention is not limited to the presence or absence of processing that makes the screw portion compatible with vacuum, and may be any structure as long as the height can be adjusted. In this embodiment, the support portion 5b is provided between the screw portion 5a and the reverse screw portion 5c. However, the support portion 5b may be omitted, and the presence or absence of the support portion 5b is not particularly limited. .

また、ネジ部５ａと逆ネジ部５ｃとの関係が逆ネジとなっていればよく、試料台底面部分が順ネジ、基底側が逆ネジであってもよくネジ部５ａと逆ネジ部５ｃとが逆ネジとなる関係であるならばよく、特に底面部４と基底部７とに形成したネジ部に限定しない。この構成では、オリフラのあるウェハにおいても電極部分２と試料台底面部分４の両側にオリフラ部分１ａに対応した形状を形成することもでき、オリフラ部分の形状により試料１と試料台底面部分４の回転を防止できる。 Further, the relationship between the screw portion 5a and the reverse screw portion 5c is only required to be a reverse screw, the sample base bottom portion may be a forward screw, and the base side may be a reverse screw, and the screw portion 5a and the reverse screw portion 5c are connected. It is sufficient that the relationship is a reverse screw, and it is not particularly limited to the screw portion formed on the bottom surface portion 4 and the base portion 7. In this configuration, a shape corresponding to the orientation flat portion 1a can be formed on both sides of the electrode portion 2 and the sample base bottom surface portion 4 even in a wafer with orientation flat, and the sample 1 and the sample base bottom surface portion 4 can be formed according to the shape of the orientation flat portion. Rotation can be prevented.

また、試料台底面部分４の形状が角形であっても回転しないため、底面部分４の形状が円柱や角柱構造であっても対応できる。底面部分４を角柱とした実施形態を図１１に示す。電極部分に形成された試料サイズの開口よりも底面部分４の形状が同じかそれ以上の大きさであればよく、これにより電界の乱れを低減でき、試料台底面部分４が回転せず高さ調整が可能となる。この実施例の構造でも、実施例１と同様にリターディング電界の乱れた領域を低減することができ、電極表面と試料表面とを略平坦化しひさしを設けた構造の効果が確認できた。 In addition, since the sample base bottom surface portion 4 does not rotate even if the shape of the bottom surface portion 4 is square, it can be handled even if the shape of the bottom surface portion 4 is a cylinder or prismatic structure. An embodiment in which the bottom portion 4 is a prism is shown in FIG. It is only necessary that the shape of the bottom surface portion 4 is the same or larger than the sample size opening formed in the electrode portion, whereby electric field disturbance can be reduced, and the height of the sample base bottom surface portion 4 does not rotate. Adjustment is possible. Even in the structure of this example, the region in which the retarding electric field was disturbed could be reduced as in Example 1, and the effect of the structure in which the electrode surface and the sample surface were substantially flattened and provided with eaves could be confirmed.

（実施例５）
実施例１同様の電極部分と試料を載せる試料台底面部分とで構成されているが、試料台底面部分４にネジ溝を切り、ステージと接続する基底部分７に試料台底面部分４のネジと合うネジ切りをした棒状部分５ａを作製して、基底部側からの棒部分と試料台底面下部との間で高さ調節機構を形成したが、基底部分に形成したネジ切りをした棒状部分を電極部分から延長されたパーツに形成してあってもよく、高さ調節用のネジ切り部分があれば当該部分の形成された部位を特定するものではない。 (Example 5)
The electrode portion is the same as that of the first embodiment and the bottom surface portion of the sample stage on which the sample is placed. A matching threaded rod-shaped portion 5a was prepared, and a height adjusting mechanism was formed between the rod portion from the base side and the bottom of the bottom surface of the sample table, but the threaded rod-shaped portion formed on the base portion was It may be formed in a part extended from the electrode part, and if there is a threaded part for height adjustment, the part where the part is formed is not specified.

また、この棒状部分は基底部分４と同一構造や、基底部分４にねじ込む構造としてあってもよく、高さ調整機構として働く機能を有していればよく形状や接続方法を限定する物ではない。この実施の形態を図１２に示す。また、実施例４に記載したように当該ネジ切りをした棒状部分に真空対応とした加工の有無を限定するものではなく、高さ調節ができる構造であればよい。この場合にも実施例１と同じくリターディング電界の乱れた領域を低減することができ、電極表面と試料表面とを略平坦化しひさしを設けた構造の効果が確認できた。 Further, this rod-shaped portion may be the same structure as the base portion 4 or a structure screwed into the base portion 4, and it does not limit the shape and the connection method as long as it has a function of acting as a height adjusting mechanism. . This embodiment is shown in FIG. Further, as described in the fourth embodiment, the presence or absence of processing corresponding to the vacuum is not limited to the threaded rod-like portion, and any structure can be used as long as the height can be adjusted. Also in this case, the region in which the retarding electric field was disturbed could be reduced as in Example 1, and the effect of the structure in which the electrode surface and the sample surface were substantially flattened and provided with eaves could be confirmed.

（実施例６）
実施例５同様の構成であるが、図１３に示すようにネジきりした部分が棒状部分の全てでなく、ネジ部５ａと支え部５ｂとで構成されていてもよい。この場合にも実施例１と同じくリターディング電界の乱れた領域を低減することができ、電極表面と試料表面とを略平坦化しひさしを設けた構造の効果が確認できた。 (Example 6)
Although it is the structure similar to Example 5, as shown in FIG. 13, the part which was screwed may be comprised by the screw part 5a and the support part 5b instead of all the rod-shaped parts. Also in this case, the region in which the retarding electric field was disturbed could be reduced as in Example 1, and the effect of the structure in which the electrode surface and the sample surface were substantially flattened and provided with eaves could be confirmed.

その他、本発明の実施の形態として上述した試料保持方法や試料保持機を基にして、当業者が適宜設計変更して実施しうる全ての試料保持方法や試料保持機も、本発明の要旨を包含する限り、本発明の範囲に属する。特に、上記態様は、試料保持部分及び試料保持機１１０を試料ステージ１０１から脱着し大気開放して用いる荷電粒子線装置に有効であるが、それに限られることはなく、脱着が困難な試料保持機構等に採用することももちろん可能である。 In addition, all sample holding methods and sample holders that can be implemented by those skilled in the art based on the sample holding methods and sample holders described above as embodiments of the present invention are also included in the gist of the present invention. As long as it is included, it belongs to the scope of the present invention. In particular, the above embodiment is effective for a charged particle beam apparatus that is used by detaching the sample holding portion and the sample holder 110 from the sample stage 101 and opening them to the atmosphere, but is not limited thereto, and the sample holding mechanism is difficult to detach. Of course, it is also possible to employ them.

以上述べたような複数の態様によれば、試料の端部でのリターディング電界乱れを緩和できる実施容易な試料保持方法及び試料保持機を提供することができる。更に、これまで説明してきた試料保持機構では、異物等の存在に因らす電位分布を安定化できるため、例えばひさし部３の近傍の一次電子線の偏向を予測することが可能となる。よってリターディング電圧の大きさに応じて、どの程度ビームが偏向を受けるかを予め走査電子顕微鏡の記憶部に記憶させておき、ひさし部３の近傍を走査する場合に、その変動分を補正してビーム走査することも可能になる。 According to the plurality of aspects as described above, it is possible to provide an easy-to-implement sample holding method and sample holder that can alleviate the retarding electric field disturbance at the end of the sample. Furthermore, since the sample holding mechanism described so far can stabilize the potential distribution due to the presence of foreign matter or the like, it is possible to predict the deflection of the primary electron beam in the vicinity of the eaves portion 3, for example. Therefore, the amount of deflection of the beam is stored in advance in the storage unit of the scanning electron microscope according to the magnitude of the retarding voltage, and when the vicinity of the eaves unit 3 is scanned, the fluctuation is corrected. It is also possible to perform beam scanning.

走査電子顕微鏡に用いられる試料保持機の構成を示す断面図。Sectional drawing which shows the structure of the sample holder used for a scanning electron microscope. 図１の試料保持機を上面から見た平面図と高さ調整部分を取り除いた形態の断面図。The top view which looked at the sample holder of FIG. 1 from the upper surface, and sectional drawing of the form which removed the height adjustment part. 電極部分のひさし状パーツを脱着可能な形態での上面から見た平面図と高さ調整部分を取り除いた形態の断面図。The top view in the form which can remove | desorb the eaves-like part of an electrode part, and sectional drawing of the form which removed the height adjustment part. 電極部分のひさし状パーツを脱着可能な形態での上面から見た平面図と高さ調整部分を取り除いた形態の断面図。The top view in the form which can remove | desorb the eaves-like part of an electrode part, and sectional drawing of the form which removed the height adjustment part. 電極部分のひさし状パーツを脱着可能な形態での上面から見た平面図と高さ調整部分を取り除いた形態の断面図。The top view in the form which can remove | desorb the eaves-like part of an electrode part, and sectional drawing of the form which removed the height adjustment part. 試料底面部分の回転防止にダブルナットとなる機構を加えた構成を示す断面図。Sectional drawing which shows the structure which added the mechanism used as a double nut to prevention of rotation of a sample bottom face part. ウェハ試料を保持した状態での平面図と高さ調整部分を取り除いた形態の断面図。The top view in the state which hold | maintained the wafer sample, and sectional drawing of the form which removed the height adjustment part. メディアディスクを保持した状態での平面図と高さ調整部分を取り除いた形態の断面図。The top view in the state which hold | maintained the media disc, and sectional drawing of the form which removed the height adjustment part. メディアディスクを保持した状態での平面図と高さ調整部分を取り除いた形態の断面図。The top view in the state which hold | maintained the media disc, and sectional drawing of the form which removed the height adjustment part. メディアディスクを保持した状態での平面図と高さ調整部分を取り除いた形態の断面図。The top view in the state which hold | maintained the media disc, and sectional drawing of the form which removed the height adjustment part. メディアディスクを保持した状態での平面図と高さ調整部分を取り除いた形態の断面図。The top view in the state which hold | maintained the media disc, and sectional drawing of the form which removed the height adjustment part. 角型試料を保持した状態での平面図と高さ調整部分を取り除いた形態の断面図。Sectional drawing of the form which removed the top view and height adjustment part in the state which hold | maintained the square-shaped sample. 試料保持機の高さ調整機構をネジ方式にした構成を示す断面図。Sectional drawing which shows the structure which made the height adjustment mechanism of the sample holder the screw system. 試料保持機の高さ調整機構を一部ネジ方式にした構成を示す断面図。Sectional drawing which shows the structure which made the height adjustment mechanism of the sample holder a part screw system. 試料保持機の高さ調整機構に逆ネジ方式を加えた構成を示す断面図。Sectional drawing which shows the structure which added the reverse screw system to the height adjustment mechanism of the sample holder. 図１０の試料保持機で角型試料を保持した状態で上面から見た平面図と高さ調整部分を取り除いた形態の断面図。The top view seen from the upper surface in the state which hold | maintained the square sample with the sample holder of FIG. 10, and sectional drawing of the form which removed the height adjustment part. 試料保持機の高さ調整機構をネジ方式にした構成を示す断面図。Sectional drawing which shows the structure which made the height adjustment mechanism of the sample holder the screw system. 試料保持機の高さ調整機構を一部ネジ方式にした構成を示す断面図。Sectional drawing which shows the structure which made the height adjustment mechanism of the sample holder a part screw system. 電子顕微鏡の構成を示す断面図。Sectional drawing which shows the structure of an electron microscope. 試料端部の異物付近での等電位分布と、本発明のひさし形状を設けた場合での等電位分布を示す断面図。Sectional drawing which shows equipotential distribution in the vicinity of the foreign material of a sample edge part, and equipotential distribution in the case of providing the eaves shape of this invention.

Explanation of symbols

１試料
１ａ試料オリフラ部
１ｂ試料サブオリフラ部
２電極部分
２ａメディアディスク用中央電極部
２ｂ試料回転制限部
２ｃ電極下層部
２ｄ電極上層部
３ひさし部
３ａメディアディスク用中央電極ひさし部
４試料底面部
４ａ試料底面ローレット部
５ａ高さ調整機構ネジ部
５ｂ高さ調整機構支え部
５ｃ高さ調整機構逆ネジ部
６回転防止用板
７高さ調節用基底部
１０貫通用足部
１１電極締結用ナット
１２電極固定用平板
１３電極固定用溝
１００試料室
１０１試料ステージ
１０２対物レンズ
１０３偏向器
１０４リターディング用電源
１０５コンデンサレンズ
１０６一次電子ビーム
１０７電子銃
１１０保持機
１１１試料
１１２試料上の異物
１２０等電位線 1 Sample 1a Sample orientation flat part 1b Sample sub orientation flat part 2 Electrode part 2a Media disk central electrode part 2b Sample rotation limiting part 2c Electrode lower layer part 2d Electrode upper layer part 3 Eaves part 3a Media disk central electrode eaves part 4 Sample bottom part 4a Sample Bottom knurled portion 5a Height adjusting mechanism screw portion 5b Height adjusting mechanism support portion 5c Height adjusting mechanism reverse screw portion 6 Anti-rotation plate 7 Height adjusting base portion 10 Penetration foot portion 11 Electrode fastening nut 12 Electrode fixing Flat plate 13 electrode fixing groove 100 sample chamber 101 sample stage 102 objective lens 103 deflector 104 retarding power source 105 condenser lens 106 primary electron beam 107 electron gun 110 holder 111 sample 112 foreign matter 120 on sample equipotential line

Claims

In the electron beam application device, in the sample holding mechanism that holds the sample by applying a negative voltage to the sample,
A support base to which a negative voltage is applied and to support the sample from below;
A sample holding mechanism, comprising: a pressing portion that presses the sample from above, the pressing portion being formed along an edge of the sample, and the negative voltage being applied.

In claim 1,
The sample holding mechanism, wherein the pressing portion is configured to be detachable.

In claim 1,
The pressing portion has a plate-like portion having a surface direction in a direction perpendicular to the pressing direction of the pressing portion, and a portion of the plate-like portion that contacts the sample is formed with the same thickness in the pressing direction. A sample holding mechanism.

In claim 3,
A portion of the plate-like portion that contacts the sample is formed around the sample along the sample edge.

In the electron beam application device, in the sample holding mechanism that holds the sample by applying a negative voltage to the sample,
A support for supporting the sample from below;
A pressing portion formed along an edge of the sample and formed along an edge of the sample;
A screw portion that supports the support base or the pressing portion so as to be movable up and down;
The sample holding mechanism, wherein the screw portion is configured to move up and down without rotating the support base.