JP2009070604A

JP2009070604A - Sample support stage for observing three-dimensional structure, protractor and three-dimensional structure observing method

Info

Publication number: JP2009070604A
Application number: JP2007235315A
Authority: JP
Inventors: Kenta Yoshida; 健太吉田; Tsukasa Hirayama; 司平山; Kazuo Yamamoto; 和生山本; Rai Nae; 蕾苗; Nobuo Tanaka; 信夫田中; Akira Saito; 晃齋藤; Jun Yamazaki; 順山崎
Original assignee: Nagoya University NUC; Japan Fine Ceramics Center
Current assignee: Nagoya University NUC; Japan Fine Ceramics Center
Priority date: 2007-09-11
Filing date: 2007-09-11
Publication date: 2009-04-02

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sample support stage for observing a three-dimensional structure of high versatility with a sample constitution while adopting a constitution capable of always holding a sample in the visual field center of an electron microscope, a protractor and a three-dimensional structure observing method. <P>SOLUTION: This sample support stage 30 has a base 31 and a sample support member 32 rotatably arranged to the base 31, and is arranged via a holder 10 in a tip part of a rotary member 16 rotatable in a ± specific angle range from a reference attitude. The protractor 40 marked with a plurality of angle graduations at a specific angle interval is installed on the sample support stage 30. While adjusting an index 34 of the sample support member 32 to the graduations 42 of the protractor 40, a plurality of turning angle states rotated stepwise at a specific angle interval to the base 31 are maintained, and the sample can be observed from all the directions of 360° by successively rotating a rotary member at the ± specific angle in the respective turning angle states. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は、試料を３６０°全角傾斜させて３次元的に構造を観察可能な３次元構造観察用の試料支持台とこれに適した分度器、及びその３次元構造観察方法に関する。 The present invention relates to a sample support base for three-dimensional structure observation capable of observing a structure three-dimensionally by tilting a sample at 360 ° full angle, a protractor suitable for this, and a three-dimensional structure observation method thereof.

例えば観察対象たる試料の組織やその構造を観察する場合、高い空間分解能を有する透過電子顕微鏡（以下、ＴＥＭ：Transmission Electron Microscopeと称すことがある）によって行うことが必要である。ＴＥＭは、電子線を試料に照射し、試料と相互作用して透過した電子線を結像・拡大表示する。ＴＥＭにより得られる像は、試料を透過した電子線の投影像であるため、ある一定角度から電子線を透過させた場合、試料の厚さ方向の情報は加算されて２次元像となり、この２次元的な像のみでは的確に試料構造等を把握することが困難である。そこで近年では、試料を３６０°全角傾斜して撮影した複数枚の像を組み合わせることで３次元的な像として再生し、厚さ方向の情報をも抽出できる３次元情報再生法（電子線トモグラフィー）が採用されている。これを採用した電子顕微鏡として、例えば特許文献１や特許文献２がある。 For example, when observing the structure or structure of a sample to be observed, it is necessary to use a transmission electron microscope (hereinafter also referred to as TEM: Transmission Electron Microscope) having high spatial resolution. The TEM irradiates the sample with an electron beam and forms an image of the transmitted electron beam through interaction with the sample. Since the image obtained by TEM is a projection image of the electron beam that has passed through the sample, when the electron beam is transmitted from a certain angle, the information in the thickness direction of the sample is added to form a two-dimensional image. It is difficult to accurately grasp the sample structure or the like only with a dimensional image. Therefore, in recent years, a three-dimensional information reproduction method (electron beam tomography) that can reproduce a three-dimensional image by combining a plurality of images taken by tilting the sample at 360 ° full-angle and extract information in the thickness direction. Is adopted. As an electron microscope employing this, there are, for example, Patent Document 1 and Patent Document 2.

ところで、一般的にＴＥＭ観察では、薄片状に形成された試料を、回転可能なロッドの先端部に設置されるホルダーのリング状試料支持台に固定している。そのうえで、例えば特許文献３のように、ホルダー及び試料支持台がそれぞれ互いに異なる方向へ一定の角度で傾斜可能な２軸傾斜機構を採用して、試料をｘｙｚ方向に任意に傾斜できるようになっているものがある。しかし、薄片状の試料を大きく傾斜させると、電子線の透過距離が大きくなってしまう。また、試料支持台を大きく傾斜させると、当該試料支持台が電子線の経路を塞いでしまう。さらに、高空間分解能のＴＥＭほど電子レンズのギャップ（距離）は狭く設計されているため、ホルダーを挿入する試料室の幅は狭くなりホルダーの傾斜角度に限界がある。などの理由により、従来からの汎用ＴＥＭにおける試料の傾斜角度範囲は±７０度程度であった。これでは、図９に示されるように、観察可能領域（角度）が限られて情報欠落領域（角度）が生じてしまい、試料を全角方向から観察できず３次元観察は根本的に不可能となる。 By the way, in general, in TEM observation, a sample formed in a thin piece is fixed to a ring-shaped sample support of a holder installed at the tip of a rotatable rod. In addition, a sample can be arbitrarily tilted in the xyz direction by adopting a biaxial tilting mechanism in which the holder and the sample support base can tilt at different angles in different directions as in Patent Document 3, for example. There is something. However, if the flaky sample is tilted greatly, the transmission distance of the electron beam becomes large. In addition, if the sample support is tilted greatly, the sample support will block the electron beam path. Furthermore, since the gap (distance) of the electron lens is designed to be narrower as the TEM has a higher spatial resolution, the width of the sample chamber into which the holder is inserted becomes narrower and the tilt angle of the holder is limited. For these reasons, the tilt angle range of the sample in the conventional general-purpose TEM is about ± 70 degrees. In this case, as shown in FIG. 9, the observable region (angle) is limited and an information missing region (angle) is generated, and the sample cannot be observed from all directions, and three-dimensional observation is fundamentally impossible. Become.

そこで特許文献１では、試料の先端部を突起状に形成し、当該突起の軸心をロッド（及びホルダー）の回転軸と平行な状態で設置したうえで、ホルダーを３６０°全方向に回転させることで、上記問題を生じることなく全角傾斜観察すなわち３次元構造観察を可能としている。特許文献２では、ロッド先端のホルダーや試料支持台の詳細な構成が記載されていないが、試料の３次元構造観察に際して試料を３６０°全方向に回転させたとき、常に試料を電子顕微鏡の視野中心（ユーセントリック位置）に保持できる技術を提案している。その他、特許文献４には、針状の試料支持体の先端に試料を固定し、電子線の入射方向に対して直角な水平面にて３６０°周回可能な電子顕微鏡用ホルダーが開示されている。また、特許文献５には、ロッドの先端部に球体を設けることで試料をｘｙｚ方向へ任意に位置設定可能とすることで、３次元構造観察において試料を電子顕微鏡の視野中心で保持可能としている。 Therefore, in Patent Document 1, the tip of the sample is formed in a projection shape, and the holder is rotated in all directions by 360 ° after the axis of the projection is placed in parallel with the rotation axis of the rod (and the holder). Thus, full-angle tilt observation, that is, three-dimensional structure observation can be performed without causing the above problem. Patent Document 2 does not describe the detailed configuration of the rod tip holder or the sample support table. However, when the sample is rotated in all directions at 360 ° during the three-dimensional structure observation of the sample, the sample is always viewed in the field of view of the electron microscope. A technology that can be held in the center (eucentric position) is proposed. In addition, Patent Document 4 discloses an electron microscope holder in which a sample is fixed to the tip of a needle-shaped sample support and can be rotated 360 ° in a horizontal plane perpendicular to the incident direction of an electron beam. Further, in Patent Document 5, a sample can be held at the center of the field of view of an electron microscope in three-dimensional structure observation by providing a sphere at the tip of a rod so that the sample can be arbitrarily positioned in the xyz direction. .

特許第３６７７８９５号公報Japanese Patent No. 3677795 特開２００１−３１２９８９号公報JP 2001-312989 A 特開平６−６８８２８号公報JP-A-6-68828 特開２００７−１８８９０５号公報JP 2007-188905 A 特開２００１−２５６９１２号公報JP 2001-256912 A

特許文献１では、１軸全角傾斜機構なので、試料の突起部をロッドの回転軸上に正確に位置合わせする必要がある。そのために、わざわざ目印として光軸上に十字のパターンが挿入された光学顕微鏡により確認したりしているが、μｍ単位で正確に突起をロッドの回転軸上に位置合わせするには限界があると共に、その確認作業も煩雑である。突起部がロッドの回転軸からズレていると、試料傾斜時の視野ずれが数百μｍになり操作性を損なうのみならず、焦点合わせが可能な視野が数μｍ角に限定されるという問題があり、観察可能な傾斜角度が極めて限定されることになる。つまり、設置当初〜低角傾斜において試料が電子顕微鏡の視野内に存在していても、高角傾斜させるにつれて試料が視野外へ外れてしまい、結果として図９に示すような情報欠落領域が生じてしまう。この問題は、ＴＥＭが高空間分解能仕様であり高い倍率で観察可能であればあるほど顕著となる。また、試料支持台へ設置した当初は試料がロッドの回転軸上にあったとしても、全角傾斜させながらＴＥＭ観察していくうちに、試料が観察電子線による熱振動や機械振動によりドリフトして、ロッドの回転軸から外れてしまう場合もある。１軸全角傾斜機構であれば、このような経時的な位置ズレに対応できない。 In Patent Document 1, since it is a uniaxial full-angle tilt mechanism, it is necessary to accurately align the protrusion of the sample on the rotation axis of the rod. For this purpose, it is confirmed with an optical microscope in which a cross pattern is inserted on the optical axis as a mark. However, there is a limit to accurately align the protrusion on the rotation axis of the rod in units of μm. The confirmation work is also complicated. If the protrusion is displaced from the rotation axis of the rod, the field of view shifts when the sample is tilted, resulting in a problem of not only degrading the operability but also limiting the field of view that can be focused to a few μm square. Yes, the observable inclination angle is extremely limited. That is, even if the sample is present in the field of view of the electron microscope from the beginning of installation to the low-angle tilt, the sample moves out of the field as the tilt is made high-angle, resulting in an information missing region as shown in FIG. End up. This problem becomes more prominent as the TEM has a high spatial resolution specification and can be observed at a higher magnification. Moreover, even when the sample is initially placed on the rotation axis of the rod, the sample drifts due to thermal and mechanical vibrations caused by the observation electron beam while TEM observation is performed while tilting the full angle. In some cases, the rod may deviate from the rotation axis of the rod. A uniaxial full-angle tilting mechanism cannot cope with such positional deviation over time.

これに対し特許文献２では、ロッドを回転、すなわち試料を全角傾斜させても試料が常に電子顕微鏡の視野中心で保持可能な構成となっているので、特許文献１のような問題は生じ難い。しかし、特許文献２ではロッド及びホルダーをｘｙ方向で位置調整させたうえでこれを３６０度回転させているので、ホルダーを挿入する試料室を大きくする必要がある。これでは、電子レンズのギャップを狭く設計することができず、ＴＥＭの性能が低下してしまう。したがって、特許文献２のような視野中心で保持可能な構成を採用しながらも、従来のように試料の傾斜角度範囲は±７０度程度が好ましい。 On the other hand, in Patent Document 2, since the sample can always be held at the center of the field of view of the electron microscope even if the rod is rotated, that is, the sample is inclined at all angles, the problem as in Patent Document 1 is unlikely to occur. However, in Patent Document 2, since the position of the rod and the holder is adjusted in the xy direction and then rotated 360 degrees, it is necessary to enlarge the sample chamber into which the holder is inserted. In this case, the gap of the electron lens cannot be designed to be narrow, and the performance of the TEM is deteriorated. Therefore, while adopting a configuration that can be held at the center of the field of view as in Patent Document 2, the sample tilt angle range is preferably about ± 70 degrees as in the past.

特許文献３は薄片状の試料を試料支持台へ固定しているのみなので、３次元構造観察には適さない。特許文献４では、針状の試料支持棒の先端に試料を固定しているが、電子線の入射方向に対して直角な平面において周回する機構なので、やはり３次元構造観察には適さない。また、特許文献５は特殊な機構を採用しているので、汎用性に欠ける。 Since Patent Document 3 only fixes a flaky sample to the sample support, it is not suitable for three-dimensional structure observation. In Patent Document 4, a sample is fixed to the tip of a needle-like sample support rod. However, since it is a mechanism that circulates in a plane perpendicular to the incident direction of an electron beam, it is also not suitable for three-dimensional structure observation. Moreover, since patent document 5 employ | adopts a special mechanism, it lacks versatility.

そこで、本発明は上記課題を解決するものであって、試料を常に電子顕微鏡の視野中心で保持可能な構成を採用しながら、簡素な構成で汎用性の高い３次元構造観察用の試料支持台及び分度器、並びに３次元構造観察方法を提供することを目的とする。 Therefore, the present invention solves the above-mentioned problems, and adopts a configuration that can always hold a sample at the center of the field of view of an electron microscope, while having a simple configuration and a highly versatile sample support base for three-dimensional structure observation. And a protractor, and a three-dimensional structure observation method.

本発明で提案される試料支持台は、一定の角度範囲で回転可能な回転部材の先端に設けられたホルダーに設置され、電子顕微鏡における３次元構造観察用の試料支持台であって、薄板リング状のベースと、前記ベースの片面に回転自在に配され、その先端に試料を固定する長細状の試料支持部材とを有し、前記試料支持部材の先端は前記ベースの中心に向けて配され、その回転軸が前記回転部材の回転軸と略平行となっている。回転部材の回転軸と試料支持部材の回転軸とが略平行とは、試料支持部材は基本的には回転部材の回転軸と平行に配されるが、試料観察上の都合からその回転軸の方向が若干変更される場合もあり、その場合は両回転軸が若干ズレて完全には平行となっていない場合もあることを意味する。ここでの試料支持部材の形状は、その回転軸まわりに回転可能な細長形状であれば特に限定されない。例えば、円柱形であっても構わない。本発明におけるリング状ベースは、従来の電子顕微鏡における試料支持台に相当する。 A sample support proposed in the present invention is a sample support for a three-dimensional structure observation in an electron microscope, which is installed on a holder provided at the tip of a rotating member that can rotate within a certain angular range, and is a thin plate ring. And a long and thin sample support member that is rotatably arranged on one side of the base and fixes the sample to the tip thereof, and the tip of the sample support member is arranged toward the center of the base. The rotating shaft is substantially parallel to the rotating shaft of the rotating member. The rotation axis of the rotation member and the rotation axis of the sample support member are substantially parallel. The sample support member is basically arranged in parallel with the rotation axis of the rotation member. The direction may be slightly changed, which means that the two rotation axes may be slightly shifted and not completely parallel. The shape of the sample support member here is not particularly limited as long as it is an elongated shape that can rotate around its rotation axis. For example, it may be cylindrical. The ring-shaped base in the present invention corresponds to a sample support in a conventional electron microscope.

そのうえで、前記試料支持部材をその先端部が先窄まり状となった針形状に形成し、その先端頂部に棒状の試料を固定することが好ましい。また、前記試料支持部材の側面には、該試料支持部材の回転角度を示す指標を設けておくことが好ましい。当該指標は、試料支持部材の左右両側面に設けられていてもよいし、左右どちらか一方の側面に設けられていてもよい。 In addition, it is preferable that the sample support member is formed in a needle shape having a tapered tip, and a rod-like sample is fixed to the top of the tip. Moreover, it is preferable that an index indicating a rotation angle of the sample support member is provided on a side surface of the sample support member. The index may be provided on both the left and right side surfaces of the sample support member, or may be provided on either the left or right side surface.

また、本発明では、前記試料支持台を使用した３次元構造観察に際して好適に使用される分度器を提供することができる。具体的には、試料支持部材をベースに対して一定角度で回転させた状態を維持するために、前記３次元構造観察用の試料支持台に、前記試料支持部材と対向状に組み付けられ、前記試料支持部材との対向面には、正面視において前記試料支持部材を中心にして囲むように、一定角度間隔で複数の角度目盛りが印されている。 Moreover, in this invention, the protractor used suitably at the time of the three-dimensional structure observation using the said sample support stand can be provided. Specifically, in order to maintain the state in which the sample support member is rotated at a constant angle with respect to the base, the sample support member is assembled to the sample support table for three-dimensional structure observation so as to face the sample support member, On the surface facing the sample support member, a plurality of angle scales are marked at regular angular intervals so as to surround the sample support member in the front view.

この分度器は薄板部材であって、前記試料支持台のベースを挿入可能な開口が形成されており、当該開口に、前記試料支持部材の対向面側から前記ベースを挿入することで、前記分度器が前記ベースに対して直角に組み付けられる。 The protractor is a thin plate member, and an opening into which the base of the sample support base can be inserted is formed, and the protractor is inserted into the opening from the opposite surface side of the sample support member. It is assembled at right angles to the base.

前記ベースの片面には、前記分度器の挿入限界を規制するストッパーを設けておくことが好ましい。当該ストッパーは、試料支持部材と同じ面であると反対面であると問わない。また、前記ストッパーは、前記分度器を前記ベースの中心よりも前記試料支持部材の対向面側寄りにて位置規制可能な位置に設けておく。 It is preferable that a stopper for restricting the insertion limit of the protractor is provided on one side of the base. The stopper may be the same surface as the sample support member or the opposite surface. In addition, the stopper is provided at a position where the protractor can be position-regulated closer to the opposing surface side of the sample support member than the center of the base.

前記回転部材は、電子顕微鏡へ装着する際の奥行きを微調整する微動機構と、前記回転部材の回転軸に垂直な面内において前記回転部材位置を調整する第１の調整機構と、前記回転部材の電子顕微鏡鏡への装着角度を調整するための第２の調整機構と、によって回転軸が制御されており、当該回転部材の先端部にホルダーを介して前記試料支持部材が設置される。これにより、常に試料が電子顕微鏡の視野中心に保持されるよう、電子線に対する試料の位置や角度が制御される。 The rotating member includes a fine adjustment mechanism for finely adjusting a depth when the rotating member is attached to the electron microscope, a first adjusting mechanism for adjusting the position of the rotating member in a plane perpendicular to a rotation axis of the rotating member, and the rotating member. The rotation axis is controlled by a second adjustment mechanism for adjusting the mounting angle of the electron microscope to the electron microscope mirror, and the sample support member is installed at the tip of the rotation member via a holder. Thereby, the position and angle of the sample with respect to the electron beam are controlled so that the sample is always held at the center of the field of view of the electron microscope.

また、前記試料支持台は、前記試料支持部材の回転軸に対して直交する方向の回転軸を中心として回転自在であり、前記回転部材の傾斜軸と前記ベースの傾斜軸とによって２軸傾斜可能となっている。 The sample support can be rotated about a rotation axis in a direction perpendicular to the rotation axis of the sample support member, and can be tilted in two axes by the tilt axis of the rotation member and the tilt axis of the base. It has become.

このような試料支持台によって、本発明ではさらに次のような電子顕微鏡における３次元構造観察方法を提供することができる。すなわち、基準姿勢から±一定角度範囲で回転可能な回転部材の先端部に、ベースと該ベースに対して回転自在に配された試料支持部材とを有する試料支持台を、ホルダーを介して設置する。そして、前記試料支持部材を前記ベースに対して一定角度間隔で段階的に回転させた複数の回転角度状態を維持させ、それぞれの回転角度状態において順次前記回転部材を±一定角度で回転させることで、試料を３６０°全方向から観察することができる。 With such a sample support, the present invention can further provide the following three-dimensional structure observation method in an electron microscope. That is, a sample support base having a base and a sample support member that is rotatably arranged with respect to the base is installed via a holder at the tip of a rotating member that can rotate within a range of ± a certain angle from the reference posture. . A plurality of rotation angle states in which the sample support member is rotated stepwise with respect to the base at regular angle intervals are maintained, and the rotation members are sequentially rotated at a certain angle in each rotation angle state. The sample can be observed from all directions of 360 °.

さらに、前記試料支持台に一定角度間隔で複数の角度目盛りが印された分度器を組み付ければ、前記試料支持部材の段階的な回転角度状態の変更を、前記試料支持部材の側面に設けられた指標を前記分度器の目盛りに合わせることで行うことができる。 Further, if a protractor with a plurality of angular scales marked at regular angular intervals is assembled to the sample support base, a stepwise rotation angle state change of the sample support member is provided on the side surface of the sample support member. This can be done by adjusting the index to the scale of the protractor.

本発明の試料支持台によれば、回転部材自体は一定の角度範囲で回転可能となっているだけであるが、試料支持部材をベースの片面に回転自在に配していることで、試料支持部材の回転角度と回転部材の回転角度とを組み合わせることで、容易に試料を３６０°全方向から観察、すなわち電子顕微鏡において３次元構造観察用をすることができる。従来の試料支持台に相当するベースに、細長状の試料支持部材を回転自在に配しただけの簡単な構成となっているので、従来からの電子顕微鏡にそのまま適用することができ、汎用性も高い。このとき、試料支持部材の先端をベースの中心に向けて配してあれば、試料支持部材の先端に固定される観察用試料をベースの中心に位置させることができる。また、試料支持部材の回転軸が回転部材の回転軸と略平行となっていれば、回転部材の回転に伴い試料を回転させることができ、かつ回転部材の回転軸を微調整することで、試料を電子顕微鏡の視野中心にて回転させることができる。 According to the sample support base of the present invention, the rotating member itself can only be rotated within a certain angle range, but the sample support member is arranged on one side of the base so as to be freely rotatable. By combining the rotation angle of the member and the rotation angle of the rotation member, the sample can be easily observed from all directions of 360 °, that is, for observation of a three-dimensional structure in an electron microscope. Since it has a simple configuration in which an elongated sample support member is rotatably arranged on a base corresponding to a conventional sample support base, it can be applied to a conventional electron microscope as it is, and versatility is also provided. high. At this time, if the tip of the sample support member is arranged toward the center of the base, the observation sample fixed to the tip of the sample support member can be positioned at the center of the base. Further, if the rotation axis of the sample support member is substantially parallel to the rotation axis of the rotation member, the sample can be rotated along with the rotation of the rotation member, and by finely adjusting the rotation axis of the rotation member, The sample can be rotated at the center of the field of view of the electron microscope.

試料支持部材を針形状に形成しておけば、その先端頂部に試料を固定するだけで、的確に試料を試料支持部材の断面中心、すなわち試料支持部材の回転軸上に位置させることができる。また、試料を棒状に形成しておけば、例えば薄板形状の試料のように、試料自体の形状によって情報欠落領域が生じることなく確実に３６０°全方向からの観察が可能となり、３次元構造観察用に適している。 If the sample support member is formed in a needle shape, the sample can be accurately positioned on the center of the cross section of the sample support member, that is, on the rotation axis of the sample support member, simply by fixing the sample to the top of the tip. Further, if the sample is formed in a rod shape, for example, a thin plate-like sample can be reliably observed from all directions at 360 ° without causing an information missing region due to the shape of the sample itself, and a three-dimensional structure observation is possible. Suitable for use.

試料支持部材の側面に指標を設けていれば、当該試料支持部材をベースに対して回転させた角度を的確かつ容易に把握することができる。 If an index is provided on the side surface of the sample support member, the angle at which the sample support member is rotated with respect to the base can be accurately and easily grasped.

その際、試料支持部材を中心にして囲むように一定角度間隔で複数の角度目盛りが印された分度器を使用し、試料支持部材の指標を分度器の目盛りに合わせて回転させれば、試料支持部材のベースに対する回転角度をより的確かつ容易に把握することができる。また、試料支持部材をベースに対して段階的に回転させる場合には、各回転角度状態の角度間隔を均等化し易い。 At that time, if a protractor with a plurality of angular scales marked at regular angular intervals to surround the sample support member is used, and the index of the sample support member is rotated according to the scale of the protractor, the sample support member The rotation angle with respect to the base can be grasped more accurately and easily. Further, when the sample support member is rotated stepwise with respect to the base, it is easy to equalize the angular intervals of the respective rotation angle states.

ベースに分度器の挿入限界を規制するストッパーを設けて、分度器をベースの中心よりも試料支持部材の対向面側（反対側）に位置規制可能としていれば、試料を観察するに当たり分度器が試料と接触することを避けられ、かつ分度器が電子線を遮蔽することもないので、確実に試料の３次元構造観察が可能となる。 If the base is provided with a stopper that restricts the insertion limit of the protractor, and the protractor can be positioned on the opposite side (opposite side) of the sample support member from the center of the base, the protractor will contact the sample when observing the sample. Since the protractor does not shield the electron beam, the three-dimensional structure of the sample can be reliably observed.

試料支持台を回転軸の角度調整可能な回転部材の先端部に設けることで、常に試料が電子顕微鏡の視野中心に保持されるよう、電子線に対する試料の位置や角度が制御されていれば、試料を３６０°回転させても試料が電子顕微鏡の視野外へ外れるおそれはないので、情報欠落領域が生じることを回避できる。また、試料支持台が２軸傾斜可能となっていれば、試料が試料支持部材の先端に傾斜して固定されていても、試料を試料支持部材の回転軸と平行になるよう調整できる。 If the position and angle of the sample with respect to the electron beam are controlled so that the sample is always held at the center of the field of view of the electron microscope by providing the sample support at the tip of the rotating member capable of adjusting the angle of the rotation axis, Even if the sample is rotated 360 °, there is no possibility that the sample is out of the field of view of the electron microscope, so that it is possible to avoid the occurrence of an information missing region. Further, if the sample support base can be tilted in two axes, the sample can be adjusted to be parallel to the rotation axis of the sample support member even if the sample is tilted and fixed to the tip of the sample support member.

回転部材を基準姿勢から±一定角度範囲のみで回転可能な構成としていれば、試料を観測する試料室を大きくする必要がないので、電子レンズのギャップを小さくでき、電子顕微鏡の空間分解能を高水準にできる。また、この構成は従来からの汎用電子顕微鏡にも採用されている構成と同様なので、電子顕微鏡を特殊な構成を採用する必要がなく汎用性が高い。そのうえで、試料支持部材をベースに対して一定角度間隔で段階的に回転させた複数の回転角度状態を維持させ、それぞれの回転角度状態において順次前記回転部材を±一定角度で回転させれば、簡素な構成の試料支持台を使用しながら確実に試料を３６０°全方向から観察することができる。 If the rotating member has a structure that can rotate only within a certain angle range from the reference posture, there is no need to enlarge the sample chamber for observing the sample, so the gap of the electron lens can be reduced and the spatial resolution of the electron microscope is high. Can be. In addition, since this configuration is the same as the configuration employed in conventional general-purpose electron microscopes, it is not necessary to employ a special configuration for the electron microscope, and the versatility is high. In addition, if the sample support member is maintained in a plurality of rotation angle states in which the sample support member is rotated stepwise with respect to the base at a predetermined angle interval, the rotation member is sequentially rotated at a certain angle in each rotation angle state. A sample can be reliably observed from all directions at 360 ° while using a sample support base having a simple structure.

以下に、適宜図面を参照しながら本発明の実施の形態について説明するが、これに限定されることはなく、本発明の要旨を逸脱しない範囲において種々の変更が可能である。図１に、本発明の試料支持台及び分度器、並びに３次元構造観察方法が主に適用される透過型電子顕微鏡（ＴＥＭ）の概略構成図を示す。図１において、ＴＥＭ１は従来からの一般的なものと同様であり、上方から電子銃（フィラメント）２と、第１収束レンズ３と、第２収束レンズ４と、対物レンズ５と、中間レンズ６と、投射レンズ７と、蛍光板８と、カメラ９とを有し、第２収束レンズ４と対物レンズ５との間の試料室内に観察対象たる試料Ｓ（図１には図示せず）を保持するホルダー１０が配されている。なお、第１収束レンズ３及び第２収束レンズ４が照射系であり、対物レンズ５、中間レンズ６、および投射レンズ７が結像系である。電子銃２から照射された電子線Ｅは、第１・第２の収束レンズ３・４によりスポット状に収束されて試料Ｓを透過する。電子線Ｅが試料Ｓを透過することで、試料Ｓから二次電子が放出される。試料Ｓを透過した二次電子は対物レンズ５により結像され、その像は投射レンズ７により拡大され、蛍光板８に投影される。蛍光板８に投影された透過電子像は、カメラ９を介して図外のモニターに表示される。符号１４は、ＴＥＭ１の筐体である。試料Ｓは、ロッド１６の角度等を調整する試料傾斜機構１５により電子線軸上でその位置や角度を変更調整可能で、試料Ｓを電子顕微鏡の視野中心に保持しながら、種々の角度から透過電子像を観察することが可能となっている。 Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate. However, the present invention is not limited thereto, and various modifications can be made without departing from the scope of the present invention. FIG. 1 shows a schematic configuration diagram of a transmission electron microscope (TEM) to which a sample support base, a protractor, and a three-dimensional structure observation method of the present invention are mainly applied. In FIG. 1, a TEM 1 is the same as a conventional one, and an electron gun (filament) 2, a first converging lens 3, a second converging lens 4, an objective lens 5, and an intermediate lens 6 are viewed from above. A projection lens 7, a fluorescent plate 8, and a camera 9, and a sample S (not shown in FIG. 1) to be observed is held in the sample chamber between the second focusing lens 4 and the objective lens 5. A holder 10 is arranged. The first converging lens 3 and the second converging lens 4 are an irradiation system, and the objective lens 5, the intermediate lens 6, and the projection lens 7 are an imaging system. The electron beam E irradiated from the electron gun 2 is converged in a spot shape by the first and second converging lenses 3 and 4 and passes through the sample S. When the electron beam E passes through the sample S, secondary electrons are emitted from the sample S. The secondary electrons that have passed through the sample S are imaged by the objective lens 5, and the image is magnified by the projection lens 7 and projected onto the fluorescent screen 8. The transmission electron image projected on the fluorescent screen 8 is displayed on a monitor (not shown) via the camera 9. Reference numeral 14 denotes a casing of the TEM1. The position and angle of the sample S on the electron beam axis can be changed and adjusted on the electron beam axis by the sample tilting mechanism 15 that adjusts the angle of the rod 16 and the like. The image can be observed.

図２に、試料傾斜機構１５の一例の横断平面図を示す。なお、以下ではロッド１６の回転軸と略平行な方向（図２の左右方向）をｘ方向とし、水平面にてｘ方向に対して直角な方向（図２の上下方向）をｙ方向とし、ｘ方向及びｙ方向と直交しＴＥＭの高さ方向に相当する方向（図２の正背面方向）をｚ方向とする。図２において試料支持台３０を有するホルダー１０は、円柱形のロッド１６の先端に固定されており、当該ロッド１６は左右両面が開口する円筒形の鞘管１７に挿入・固定されている。鞘管１７の先端は球面になっており、球面座１８内に納められる構造である。ロッド１６はＴＥＭ１の視野中心を通るｘ方向の回転軸Ｘ₁を中心として一定の角度範囲で回転可能となっていることで、これの先端に固定されたホルダー１０や試料Ｓも、ｘ方向の回転軸Ｘ₁を中心として一定の角度範囲で回転するようになっている。このロッド１６が本発明の回転部材に相当する。試料Ｓをｙｚ方向で高精度に制御するため、鞘管１７の外層に設けられた回転シリンダ１９上に、ｙｚ２方向から固定された微動アクチュエータ２０を設け、当該微動アクチュエータ２０とこれの対向面側に設けられたリターンスプリング２１とで鞘管１７が挟持されている。微動アクチュエータ２０は電気的パルス入力を受けて回転シリンダ１９に対して出没可能であり、球面座１８の中心Ｃを不動点としてロッド１６を数ｎｍレベルでｙｚ方向へ任意に傾斜可能である。位置復元力はリターンスプリング２１の付勢力により生成する。ロッド１６は、回転モータ２２により軸Ｘ₁まわりに回転する回転シリンダ１９と一体的に回転し、軸Ｘ₁に対して歳差運動する。このように、ロッド１６が球面座１８の中心Ｃを不動点として任意な角度でｙｚ方向へ傾斜可能であることで、ロッド１６先端のホルダー１０に設置された試料Ｓをｙｚ方向へ任意に移動できる。ｘ方向への試料の位置調整は、ロッド１６の先端部に固定された梃子２７により実現される。すなわち、把手２８を梃子２７で押し上げることで試料Ｓをｘ方向へ微動調整できる。 FIG. 2 shows a transverse plan view of an example of the sample tilting mechanism 15. In the following, the direction substantially parallel to the rotation axis of the rod 16 (the left-right direction in FIG. 2) is the x direction, the direction perpendicular to the x direction (the up-down direction in FIG. 2) on the horizontal plane is the y direction, and x A direction orthogonal to the direction and the y direction and corresponding to the height direction of the TEM (the front and back direction in FIG. 2) is defined as the z direction. In FIG. 2, a holder 10 having a sample support 30 is fixed to the tip of a cylindrical rod 16, and the rod 16 is inserted and fixed to a cylindrical sheath tube 17 that is open on both left and right sides. The distal end of the sheath tube 17 has a spherical shape and is configured to be accommodated in the spherical seat 18. Since the rod 16 is rotatable within a certain angular range around the rotation axis X ₁ in the x direction passing through the center of the field of view of the TEM ₁ , the holder 10 and the sample S fixed to the tip of the rod 16 are also in the x direction. so as to rotate at a constant angular range about an axis of rotation X _1. This rod 16 corresponds to the rotating member of the present invention. In order to control the sample S with high accuracy in the yz direction, a fine actuator 20 fixed from the yz2 direction is provided on the rotary cylinder 19 provided in the outer layer of the sheath tube 17, and the fine actuator 20 and the opposed surface side thereof are provided. The sheath tube 17 is sandwiched between the return spring 21 provided in The fine movement actuator 20 can be projected and retracted with respect to the rotating cylinder 19 upon receiving an electric pulse input, and can incline the rod 16 arbitrarily in the yz direction at a level of several nm with the center C of the spherical seat 18 as a fixed point. The position restoring force is generated by the urging force of the return spring 21. The rod 16 rotates integrally with the rotary cylinder 19 that rotates about the axis X ₁ by the rotary motor 22 and precesses with respect to the axis X ₁ . In this way, the rod 16 can be tilted in the yz direction at an arbitrary angle with the center C of the spherical seat 18 as a fixed point, so that the sample S placed on the holder 10 at the tip of the rod 16 can be arbitrarily moved in the yz direction. it can. Adjustment of the position of the sample in the x direction is realized by an insulator 27 fixed to the tip of the rod 16. That is, the sample S can be finely adjusted in the x direction by pushing up the handle 28 with the lever 27.

ロッド１６は回転シリンダ１９をガイドとして回転するほか、球面座１８をもガイドにして回転する。このとき、ロッド１６の回転軸が球面座１８の中心Ｃからズレていると、ロッド１６は、これの回転軸と球面座１８中心Ｃとの離心距離を半径とした首振り回転現象を起し、試料Ｓ自体もロッド１６の回転軸Ｘ₁周りに歳差運動を起こしてしまう。そこで、ロッド１６の回転軸Ｘ₁が球面座１８の中心Ｃと一致するように、回転シリンダ１９の位置を微調整するためのシリンダ調整機構２３がｙｚ２方向に設けられている。この調整プロセスをユーセントリック調整と呼ぶ。このユーセントリック調整により、試料Ｓに対しては不動の回転軸を形成でき、この軸上に試料Ｓの目的部位を微動アクチュエータ２０で移動できることから、試料Ｓを回転観察したときの視野ずれや焦点ずれを抑えることが可能になる。しかし、ロッド１６の回転軸方向は回転シリンダ１９と筐体１４との位置関係で決まるため、常にＴＥＭ１の視野中心を通るとは限らない。そこで、回転シリンダ１９を保持し、球面座１８を含むシリンダガイド２４を第２球面座２５で筐体１４に固定し、筐体１４とシリンダガイド２４との相対位置関係を調整するシリンダガイドの位置を微調整するためのシリンダガイド調整機構２６を設けている。これにより、ロッド１６や回転シリンダ１９のユーセントリック条件を崩すことなく、また試料Ｓの形状、ロッド１６における試料Ｓのｙｚ方向取りつけ位置、及び観察倍率によらず、ロッド１６及びこれの先端に設けられたホルダー１０を第２球面座２５で回転させ、ロッド１６等の回転軸Ｘ₁を電子顕微鏡の視野中心に通るように設定できる。なお、シリンダ調整機構２３が本発明の第１の調整機構に、シリンダガイド調整機構２６が本発明の第２の調整機構に、梃子２７が本発明の微動機構に、それぞれ相当する。 The rod 16 rotates using the rotating cylinder 19 as a guide and also rotates using the spherical seat 18 as a guide. At this time, if the rotation axis of the rod 16 deviates from the center C of the spherical seat 18, the rod 16 causes a swinging rotation phenomenon in which the eccentric distance between the rotation axis of the spherical seat 18 and the center C of the spherical seat 18 is a radius. The sample S itself also precesses around the rotation axis X _{1 of the} rod 16. Therefore, a cylinder adjustment mechanism 23 for finely adjusting the position of the rotary cylinder 19 is provided in the yz2 direction so that the rotation axis X ₁ of the rod 16 coincides with the center C of the spherical seat 18. This adjustment process is called eucentric adjustment. By this eucentric adjustment, a stationary rotation axis can be formed with respect to the sample S, and the target portion of the sample S can be moved on this axis by the fine actuator 20, so that the visual field shift and focus when the sample S is rotated and observed. The shift can be suppressed. However, since the rotation axis direction of the rod 16 is determined by the positional relationship between the rotation cylinder 19 and the housing 14, it does not always pass through the center of the field of view of the TEM 1. Therefore, the position of the cylinder guide that holds the rotating cylinder 19, fixes the cylinder guide 24 including the spherical seat 18 to the housing 14 with the second spherical seat 25, and adjusts the relative positional relationship between the housing 14 and the cylinder guide 24. A cylinder guide adjusting mechanism 26 for finely adjusting the angle is provided. Accordingly, the eucentric conditions of the rod 16 and the rotating cylinder 19 are not broken, and the rod 16 and the tip of the rod 16 are provided regardless of the shape of the sample S, the mounting position of the sample S in the yz direction, and the observation magnification. the holder 10 is rotated by the second spherical seat 25, it can be set to pass through the rotation axis X ₁ such as the rod 16 in the center of the field of view of the electron microscope. The cylinder adjustment mechanism 23 corresponds to the first adjustment mechanism of the present invention, the cylinder guide adjustment mechanism 26 corresponds to the second adjustment mechanism of the present invention, and the lever 27 corresponds to the fine movement mechanism of the present invention.

次に、ロッド１６の先端に固定されるホルダー１０と、当該ホルダー１０に設置される本発明の試料支持台３０及び分度器４０について、図３〜図８を参照しながら詳しく説明する。図３に、ロッド１６の先端部分の拡大平面図を示す。図３に示すごとく、ホルダー１０は平板矩形を呈しており、先端寄り部位に穿設された開口１１内に試料支持台３０等を設置する設置台１２が配されている。設置台１２は、捻りコイルバネ１３を介してホルダー１０に設置されていることで、ｙ方向の回転軸Ｙを中心に回転自在となっており、この設置台１２の中央部に、本発明の試料支持台３０及び分度器４０が配されている。このように試料支持台３０は、回転軸Ｘ₁と回転軸Ｙとの２軸傾斜可能となっていることで、試料Ｓを回転軸Ｘ₁と一致させながら全角傾斜観察が可能となる。すなわち、先ず試料Ｓが回転軸Ｘ₁からズレた位置に固定されていれば、上述のように試料傾斜機構１５によってユーセントリック調整することで、試料Ｓを回転軸Ｘ₁上に移動させる。さらに、試料Ｓが回転軸Ｘ₁に対して斜めに固定されていれば、試料支持台３０を回転軸Ｙまわりに回転傾斜させることで、試料Ｓを回転軸Ｘ₁と一致させることができる。これにより、試料Ｓが回転軸Ｘ₁に対して歳差運動することを防ぐことができる。ここまでは、従来のＴＥＭでも採用されていた機構である。 Next, the holder 10 fixed to the tip of the rod 16 and the sample support 30 and the protractor 40 of the present invention installed in the holder 10 will be described in detail with reference to FIGS. FIG. 3 shows an enlarged plan view of the tip portion of the rod 16. As shown in FIG. 3, the holder 10 has a flat rectangular shape, and an installation base 12 for installing the sample support base 30 and the like is disposed in an opening 11 formed in a portion near the tip. The installation table 12 is installed in the holder 10 via the torsion coil spring 13 so that the installation table 12 can rotate about the rotation axis Y in the y direction. The sample of the present invention is placed at the center of the installation table 12. A support base 30 and a protractor 40 are arranged. In this way, the sample support 30 can be tilted in two axes, ie, the rotation axis X ₁ and the rotation axis Y, so that full-angle tilt observation can be performed while aligning the sample S with the rotation axis X ₁ . That is, first, if the sample S is fixed at a position was displaced from the rotation axis X _1, the specimen rotation mechanism 15 as described above by eucentric adjusted, move the sample S on the rotation axis X _1. Furthermore, if the sample S is fixed at an angle relative to the axis of rotation X _1, by rotating tilting the sample holder 30 around the rotation axis Y, it is possible to match the sample S and the rotation axis X _1. Thus, it is possible to prevent the sample S precess relative to the axis of rotation X _1. Up to this point, the mechanism has been adopted in the conventional TEM.

図４は、試料支持台３０に分度器４０を組み付けた状態の平面図である。図５は、同じく試料支持台３０に分度器４０を組み付けた状態の側面図である。図６は、同じく試料支持台３０に分度器４０を組み付けた状態の正面図である。また、図７は分度器４０の正面図である。図４〜図６において試料支持台３０は、薄板リング状のベース３１と、試料Ｓを固定支持する試料支持部材３２とを有する。試料支持部材３２は先端が先窄まり状となった細針形状に形成されており、ｘ方向に沿ってベース３１の中心に向けた状態で配されている。試料支持部材３２はタングステン製とした。試料Ｓは集束イオンビーム加工装置（ＦＩＢ）によって略円柱形の棒状に形成され、試料支持部材３２の先端頂部に接着等により固定される。なお、試料支持部材３２の先端頂部は、試料支持部材３２の縦断面において略中央に位置している。試料支持部材３２は、これの先端頂部に試料Ｓを固定したとき、当該試料Ｓがベース３１の中心（ＴＥＭ１の視野中心）にあるような長さに設計されている。また、試料支持部材３２は、ベース３１の上面に固定されたアタッチメント３３に回転自在に挿入されていることで、ｘ方向に延びる軸Ｘ₂まわりに回転自在となっている。試料支持台３０をホルダー１０へ設置したとき、試料支持部材３２の回転軸Ｘ₂とロッド１６の回転軸Ｘ₁とが一致する位置状態にある。試料支持部材３２の左右両側面には、当該試料支持部材３２の回転角度を容易に確認できるようにするための２つの指標３４が、互いに水平となる状態で溶接等によって固定されている。 FIG. 4 is a plan view showing a state in which the protractor 40 is assembled to the sample support 30. FIG. 5 is a side view showing a state in which the protractor 40 is assembled to the sample support 30. FIG. 6 is a front view of a state in which the protractor 40 is assembled to the sample support 30. FIG. 7 is a front view of the protractor 40. 4 to 6, the sample support 30 includes a thin plate-shaped base 31 and a sample support member 32 that fixes and supports the sample S. The sample support member 32 is formed in a fine needle shape having a tapered tip, and is arranged in a state toward the center of the base 31 along the x direction. The sample support member 32 was made of tungsten. The sample S is formed into a substantially cylindrical rod shape by a focused ion beam processing apparatus (FIB), and is fixed to the top of the tip of the sample support member 32 by adhesion or the like. Note that the top end of the sample support member 32 is located substantially at the center in the longitudinal section of the sample support member 32. The sample support member 32 is designed to have such a length that the sample S is at the center of the base 31 (the center of the field of view of TEM1) when the sample S is fixed to the top of the tip. Further, the sample support member 32, by being inserted rotatably in the attachment 33 fixed to the upper surface of the base 31, is rotatable about the axis X ₂ extending in the x-direction. When installed the sample holder 30 to the holder 10 is in a position state where the rotation axis X ₁ of the rotary shaft X ₂ and the rod 16 of the sample support member 32 match. Two indicators 34 are attached to the left and right side surfaces of the sample support member 32 by welding or the like so that the rotation angle of the sample support member 32 can be easily confirmed.

図７において分度器４０は、平板薄肉の矩形部材であって、その上下方向の中央やや下方位置に横長溝状のスリット４１が開口している。そして、このスリット４１にベース３１を試料支持部材３２の反対側から挿入することで、図６等に示されるように、試料支持部材３２と対向する状態でベース３１に対して分度器４０が直角に組み付けられる。このとき、試料支持部材３２が分度器４０の中央部に位置している。また、ベース３１の上面の左右２箇所には、分度器４０の挿入限界を既定するストッパー３５が設けられており、当該ストッパー３５の位置まで分度器４０を挿入したとき、分度器４０はベース３１の中心よりも試料支持部材３２の対向面側（反対側）に位置している。また、分度器４０のスリット４１は、ベース３１の厚みよりも僅かに大きい程度の厚み寸法となっていることで、ベース３１は分度器４０に圧入された状態となり、分度器４０がベース３１に対してガタ付くことはない。そのうえで、分度器４０の試料支持部材３２との対向面には、試料支持部材３２を中心にして囲むように、一定角度間隔で複数の角度目盛り４２が印されている。本実施例では、４５°間隔で計８個の線状の目盛り４２が印されている。なお、図６及び図７において目盛り４２に沿った円形の線は、各目盛り４２を容易に印すための単なる基準線である。 In FIG. 7, the protractor 40 is a flat plate-shaped rectangular member, and a slit 41 having a horizontally long groove is opened at a slightly lower position in the vertical center. Then, by inserting the base 31 into the slit 41 from the opposite side of the sample support member 32, the protractor 40 is perpendicular to the base 31 while facing the sample support member 32 as shown in FIG. Assembled. At this time, the sample support member 32 is located at the center of the protractor 40. Further, stoppers 35 that define the insertion limit of the protractor 40 are provided at two positions on the left and right sides of the upper surface of the base 31. When the protractor 40 is inserted up to the position of the stopper 35, the protractor 40 is positioned from the center of the base 31. Is also located on the opposite surface side (opposite side) of the sample support member 32. In addition, the slit 41 of the protractor 40 has a thickness dimension that is slightly larger than the thickness of the base 31, so that the base 31 is pressed into the protractor 40, and the protractor 40 has a backlash with respect to the base 31. It won't stick. In addition, a plurality of angular scales 42 are marked on the surface of the protractor 40 facing the sample support member 32 at regular angular intervals so as to surround the sample support member 32 as a center. In the present embodiment, a total of eight linear scales 42 are marked at 45 ° intervals. 6 and 7, the circular line along the scale 42 is merely a reference line for easily marking each scale 42.

次に、図８を参照しながら３次元構造観察方法について説明する。先ず、棒状の試料Ｓを試料支持部材３２の配設方向（ｘ方向）に沿ってその先端頂部へ固定する。このとき、図８（Ａ）に示すように、試料支持部材３２の回転角度を示す指標３４を分度器４０の０°角目盛り４２ａに合わせ、ベース３１に対する試料支持部材３２自身の回転角度を０°にしておく。なお、試料Ｓは正確に試料支持部材３２の断面中心位置に固定する必要はない。試料Ｓが試料支持部材３２の先端頂部から若干スレた位置にあれば、試料傾斜機構１５によってｘｙｚ方向に任意にユーセントリック調整して試料Ｓを中心位置に移動させる。また、試料Ｓがロッド１６の回転軸Ｘ₁及び試料支持部材３２の回転軸Ｘ₂に対して斜めに固定されていれば、試料支持台３０を回転軸Ｙまわりに傾斜させて、試料Ｓを回転軸Ｘ₁と一致させておく。このとき、ロッド１６の回転軸Ｘ₁と試料支持部材３２の回転軸Ｘ₂とは若干ズレた略水平状態となっている。そして、図８（Ａ）に示すように、この０°角基準状態から、ロッド１６を回転軸Ｘ₁まわりに±一定角度で回転させることで、±一定角度範囲内において種々の傾斜角度における複数枚の試料ＳのＴＥＭ像を得る。本実施例では、ロッド１６を±７０°の傾斜範囲で回転させた。なお、分度器４０も試料支持台３０と一体的に回転する。 Next, a three-dimensional structure observation method will be described with reference to FIG. First, the rod-shaped sample S is fixed to the top of the tip along the arrangement direction (x direction) of the sample support member 32. At this time, as shown in FIG. 8A, the indicator 34 indicating the rotation angle of the sample support member 32 is aligned with the 0 ° angle scale 42a of the protractor 40, and the rotation angle of the sample support member 32 itself with respect to the base 31 is set to 0 °. Keep it. The sample S does not need to be accurately fixed at the center position of the cross section of the sample support member 32. If the sample S is at a position slightly displaced from the top of the tip of the sample support member 32, the sample tilting mechanism 15 arbitrarily adjusts eucentric in the xyz direction to move the sample S to the center position. Further, if the sample S is fixed at an angle to the rotational axis X ₂ of the rotary shaft X ₁ and the sample support member 32 of the rod 16, by tilting the sample holder 30 around the rotation axis Y, the sample S allowed to coincide with the rotation axis X _1. In this case, it has a substantially horizontal state was slightly shifted to the rotation axis X ₂ of the rotary shaft X ₁ and the sample support member 32 of the rod 16. Then, as shown in FIG. 8 (A), from the 0 ° angle reference state, is rotated by ± a predetermined angle about the rotation axis X ₁ of the rod 16, a plurality of various tilt angles within ± predetermined angle range A TEM image of the sample S is obtained. In this example, the rod 16 was rotated within an inclination range of ± 70 °. The protractor 40 also rotates integrally with the sample support 30.

次に、一旦ホルダー１０をＴＥＭ１から取り出し、ベース３１を水平にした状態において試料支持部材３２の指標３４を分度器４０の４５°角目盛り４２ｂに合わせ、水平状態のベース３１に対して試料支持部材３２自身の回転角度を４５°にしておく。試料支持部材３２を回転させるには、指標３４をピン部材などで押しても良いし、試料支持部材３２の後端に形成された溝３６（図６参照）にドライバーを合わせて回転させてもよい。そして、再度ホルダー１０をＴＥＭ１へセットした後、図８（Ｂ）に示す４５°角基準状態から、先と同様にロッド１６を±７０°回転させることで複数枚の試料ＳのＴＥＭ像を得る。この場合、先の０°角基準状態を基準とすれば、試料Ｓの−２５°〜＋１１５°の傾斜範囲におけるＴＥＭ像が得られることになる。さらに続いて、再度ホルダー１０をＴＥＭ１から取り出し、今度はベース３１を水平にした状態において試料支持部材３２の指標３４を分度器４０の９０°角目盛り４２ｂに合わせ、水平状態のベース３１に対して試料支持部材３２自身の回転角度を９０°にしておく。そして、再度ホルダー１０をＴＥＭ１へセットした後、図８（Ｃ）に示す９０°角基準状態から、先と同様にロッド１６を±７０°回転させることで複数枚の試料ＳのＴＥＭ像を得る。この場合、先の０°角基準状態を基準とすれば、試料Ｓの＋２０°〜＋１６０°の傾斜範囲におけるＴＥＭ像が得られることになる。この作業を、試料支持部材３２がベース３１に対して３６０°回転した状態となるまで、目盛り４２ａ〜４２ｄに合わせながら段階的に繰り返す。このように、各傾斜角度基準状態を段階的に維持させたうえで、それぞれの回転角度状態において順次ロッド１６を±同じ角度範囲で回転させることで、最終的に試料Ｓを３６０°全角傾斜させた状態のＴＥＭ像を得ることができ、これら各傾斜角度における２次元的なＴＥＭ像を制御装置にて組み合わせることで、試料Ｓの３次元像を再構成することができる。 Next, the holder 10 is once removed from the TEM 1, and the indicator 34 of the sample support member 32 is aligned with the 45 ° angle scale 42 b of the protractor 40 in a state where the base 31 is horizontal, and the sample support member 32 is aligned with the base 31 in the horizontal state. The rotation angle is set to 45 °. In order to rotate the sample support member 32, the index 34 may be pushed by a pin member or the like, or may be rotated by aligning a screwdriver with a groove 36 (see FIG. 6) formed at the rear end of the sample support member 32. . Then, after setting the holder 10 to the TEM 1 again, the TEM images of a plurality of samples S are obtained by rotating the rod 16 ± 70 ° in the same manner as before from the 45 ° angle reference state shown in FIG. 8B. . In this case, if the above 0 ° angle reference state is used as a reference, a TEM image in the inclination range of −25 ° to + 115 ° of the sample S can be obtained. Subsequently, the holder 10 is taken out of the TEM 1 again, and this time, with the base 31 in a horizontal state, the index 34 of the sample support member 32 is aligned with the 90 ° angle scale 42b of the protractor 40, and the sample is set against the horizontal base 31. The rotation angle of the support member 32 itself is set to 90 °. Then, after setting the holder 10 to the TEM 1 again, the TEM images of a plurality of samples S are obtained by rotating the rod 16 by ± 70 ° in the same manner as before from the 90 ° angle reference state shown in FIG. 8C. . In this case, if the above 0 ° angle reference state is used as a reference, a TEM image in the inclination range of + 20 ° to + 160 ° of the sample S can be obtained. This operation is repeated step by step while matching the scales 42 a to 42 d until the sample support member 32 is rotated 360 ° with respect to the base 31. In this way, after maintaining each tilt angle reference state in stages, the rod 16 is sequentially rotated within the same angular range in each rotation angle state, so that the sample S is finally tilted by 360 °. A three-dimensional image of the sample S can be reconstructed by combining the two-dimensional TEM images at the respective inclination angles with the control device.

なお、ＴＥＭ観察では、電子線の入射角αとα＋１８０°の投影像は等価なので、３次元像を再構成する場合は、１８０°（±９０°）の投影像が観察されるので必ずしも試料Ｓを３６０°全角傾斜させる必要はない。しかし、本発明では敢えて試料Ｓを全角傾斜させて３６０°全方向からの投影像を得ることで、各回転角での情報量を２倍に増やしている。これによれば、カメラの検出精度の分散や傾斜角度の読み取り誤差などの測定誤差を平均化して少なくすることができる。 In the TEM observation, since the projection images of the electron beam incident angle α and α + 180 ° are equivalent, when reconstructing a three-dimensional image, a 180 ° (± 90 °) projection image is observed, and thus the sample S is not necessarily used. It is not necessary to incline the entire angle by 360 °. However, in the present invention, the amount of information at each rotation angle is doubled by intentionally inclining the sample S at all angles to obtain a projected image from all directions of 360 °. According to this, it is possible to average and reduce measurement errors such as dispersion of detection accuracy of the camera and reading error of the tilt angle.

以上、本発明の一実施形態について説明したが、これに限られず種々の変形が可能である。特に、上記試料傾斜機構１５の構成はほんの一例であって、常に試料Ｓが電子顕微鏡１の視野中心に保持されるよう、電子線Ｅに対する試料Ｓの位置や角度が制御し得る構成のものであれば、特に限定されない。例えば、試料傾斜機構１５のｘ方向微動操作用の梃子２７は、ロッド１６の先端部に限らず、ＴＥＭ１の筐体１４においてロッド１６と対向面（反対側）に構築した梃子機構によって行うこともできる。 As mentioned above, although one Embodiment of this invention was described, it is not restricted to this, A various deformation | transformation is possible. In particular, the configuration of the sample tilt mechanism 15 is only an example, and the position and angle of the sample S with respect to the electron beam E can be controlled so that the sample S is always held at the center of the field of view of the electron microscope 1. If there is, it will not be specifically limited. For example, the lever 27 for fine movement operation in the x direction of the sample tilting mechanism 15 is not limited to the tip portion of the rod 16, but may be performed by a lever mechanism constructed on the opposite surface (opposite side) of the rod 16 in the casing 14 of the TEM 1. it can.

試料支持台３０のストッパー３５は、試料支持部材３２と反対側となるベース３１の下面に設けてもよい。また、ストッパー３５の設置個数は、１つでもよいし、３つ以上であっても構わない。分度器４０は、その中心部に大きな円形開口を穿設して、試料支持部材３２と重なる位置で位置決めされるようにすることもできる。分度器４０の外形は、矩形に限らず円形、楕円形、多角形としても構わない。また、本発明の試料支持台３０は、従来からの汎用的な試料支持台に若干の部材を加えただけの簡素な構成となっていることから、従来からある種々のＴＥＭに適用できることはもちろん、走査型電子顕微鏡（ＳＥＭ）や集束イオンビーム加工装置（ＦＩＢ）に適用することも可能である。指標３４は、試料支持部材３２の回転角度を確認できるものであれば、その形状、配設位置、固定方法などは特に限定されない。例えば、指標３４は試料支持部材３２と一体成形されていてもよいし、接着や溶接により接合されていてもよいし、試料支持部材３２に穿設した開口へ圧入固定することもできる。 The stopper 35 of the sample support 30 may be provided on the lower surface of the base 31 on the side opposite to the sample support member 32. Further, the number of stoppers 35 may be one or three or more. The protractor 40 can also be positioned at a position overlapping the sample support member 32 by drilling a large circular opening at the center thereof. The outer shape of the protractor 40 is not limited to a rectangle, and may be a circle, an ellipse, or a polygon. In addition, the sample support 30 of the present invention has a simple configuration in which some members are added to a conventional general-purpose sample support, so that it can be applied to various conventional TEMs. The present invention can also be applied to a scanning electron microscope (SEM) and a focused ion beam processing apparatus (FIB). As long as the indicator 34 can confirm the rotation angle of the sample support member 32, its shape, arrangement position, fixing method, and the like are not particularly limited. For example, the indicator 34 may be integrally formed with the sample support member 32, may be joined by adhesion or welding, or may be press-fitted and fixed to an opening formed in the sample support member 32.

そして、最も重要なのが、試料支持部材３２自身を段階的に傾斜させる角度間隔と、ロッド１６の回転角度である。すなわち、試料支持部材３２をベース３１に対して一定角度間隔で段階的に回転させた各回転角度状態において、順次ロッド１６を±一定角度で回転させることで、最終的に試料Ｓを３６０°全方向から観察できれば、試料支持部材３２自身を段階的に傾斜させる角度間隔及びロッド１６の回転角度範囲は特に限定されない。例えば、試料支持部材３２を３０°間隔や６０°間隔で回転させた基準状態を作成してもよいし、ロッド１６の回転角度範囲は±３０〜±６５°の範囲で適宜調整すればよい。 What is most important is the angle interval at which the sample support member 32 itself is inclined stepwise and the rotation angle of the rod 16. That is, in each rotational angle state in which the sample support member 32 is rotated stepwise with respect to the base 31 at regular angular intervals, the rod 16 is sequentially rotated by ± constant angles, so that the sample S is finally rotated 360 °. As long as it can be observed from the direction, the angle interval at which the sample support member 32 itself is inclined stepwise and the rotation angle range of the rod 16 are not particularly limited. For example, a reference state in which the sample support member 32 is rotated at intervals of 30 ° or 60 ° may be created, and the rotation angle range of the rod 16 may be appropriately adjusted within a range of ± 30 to ± 65 °.

ＴＥＭの概略断面図である。It is a schematic sectional drawing of TEM. 試料傾斜機構の断面平面図である。It is a section top view of a sample inclination mechanism. ロッド先端部分の要部拡大平面図である。It is a principal part enlarged plan view of a rod tip part. 試料支持台へ分度器を組み付けた状態の平面図である。It is a top view of the state which assembled | attached the protractor to the sample support stand. 試料支持台へ分度器を組み付けた状態の側面図である。It is a side view of the state which attached the protractor to the sample support stand. 試料支持台へ分度器を組み付けた状態の正面図である。It is a front view of the state which attached the protractor to the sample support stand. 分度器の正面図である。It is a front view of a protractor. ３次元構造観察方法の各工程における回転機構説明図である。It is rotation mechanism explanatory drawing in each process of a three-dimensional structure observation method. 従来のＴＥＭ観察における観察可能領域を示す説明図である。It is explanatory drawing which shows the observable area | region in the conventional TEM observation.

符号の説明Explanation of symbols

１透過型電子顕微鏡（ＴＥＭ）
２電子銃
３第１収束レンズ
４第２収束レンズ
５対物レンズ
６中間レンズ
７投射レンズ
８蛍光板
９カメラ
１０ホルダー
１２設置台
１３コイルバネ
１４筐体
１５試料傾斜機構
１６ロッド（回転部材）
１７鞘管
１８球面座
１９回転シリンダ
２０微動アクチュエータ
２１リターンスプリング
２２回転モータ
２３シリンダ調整機構
２４シリンダガイド
２５球面座
２６シリンダガイド調整機構
２７梃子
２８把手
３０試料支持台
３１ベース
３２試料支持部材
３３アタッチメント
３４指標
３５ストッパー
４０分度器
４１スリット
４２目盛り
Ｃ球面座の中心
Ｅ電子線
Ｓ試料
Ｘ₁ ロッドの回転軸
Ｘ₂ 試料支持部材の回転軸

1 Transmission electron microscope (TEM)
2 Electron gun 3 First converging lens 4 Second converging lens 5 Objective lens 6 Intermediate lens 7 Projection lens 8 Fluorescent screen 9 Camera 10 Holder 12 Installation base 13 Coil spring 14 Housing 15 Sample tilting mechanism 16 Rod (rotating member)
17 Cylinder tube 18 Spherical seat 19 Rotating cylinder 20 Fine movement actuator 21 Return spring 22 Rotating motor 23 Cylinder adjustment mechanism 24 Cylinder guide 25 Spherical seat 26 Cylinder guide adjustment mechanism 27 Insulator 28 Handle 30 Sample support base 31 Base 32 Sample support member 33 Attachment 34 Indicator 35 Stopper 40 Protractor 41 Slit 42 Scale C Center of spherical seat E Electron beam S Sample X ₁ Rotating axis X ₂ Rotating axis of sample support member

Claims

一定の角度範囲で回転可能な回転部材の先端に設けられたホルダーに設置され、電子顕微鏡における３次元構造観察用の試料支持台であって、
薄板リング状のベースと、前記ベースの片面に回転自在に配され、その先端に試料を固定する長細状の試料支持部材とを有し、
前記試料支持部材の先端は前記ベースの中心に向けて配され、その回転軸が前記回転部材の回転軸と略平行である３次元構造観察用の試料支持台。 A sample support for a three-dimensional structure observation in an electron microscope, which is installed in a holder provided at the tip of a rotating member capable of rotating within a certain angle range;
A thin ring-shaped base, and a long and thin sample support member that is rotatably arranged on one side of the base and fixes the sample to the tip thereof,
A sample support for observing a three-dimensional structure, wherein the tip of the sample support member is arranged toward the center of the base, and the rotation axis thereof is substantially parallel to the rotation axis of the rotation member.

前記試料支持部材は、その先端部が先窄まり状となった針形状に形成されており、その先端頂部に棒状の試料を固定する請求項１に記載の３次元構造観察用の試料支持台。 The sample support base for three-dimensional structure observation according to claim 1, wherein the sample support member is formed in a needle shape having a tapered tip end portion, and a rod-like sample is fixed to the top end portion of the tip end. .

前記試料支持部材の側面には、該試料支持部材の回転角度を示す指標が設けられている請求項１または請求項２に記載の３次元構造観察用の試料支持台。 The sample support base for three-dimensional structure observation according to claim 1 or 2, wherein an index indicating a rotation angle of the sample support member is provided on a side surface of the sample support member.

請求項１ないし請求項３のいずれかに記載の３次元構造観察用の試料支持台に、前記試料支持部材と対向状に組み付けられ、
前記試料支持部材との対向面には、正面視において前記試料支持部材を中心にして囲むように、一定角度間隔で複数の角度目盛りが印されている電子顕微鏡における３次元構造観察用の分度器。 A sample support for observing a three-dimensional structure according to any one of claims 1 to 3, wherein the sample support is assembled to face the sample support member.
A protractor for observing a three-dimensional structure in an electron microscope, wherein a plurality of angle scales are marked on a surface facing the sample support member at a predetermined angular interval so as to surround the sample support member in the front view.

前記分度器は薄板部材であって、前記試料支持台のベースを挿入可能な開口が形成されており、
当該開口に、前記試料支持部材の対向面側から前記ベースを挿入することで、前記分度器が前記ベースに対して直角に組み付けられる請求項４に記載の３次元構造観察用の分度器。 The protractor is a thin plate member, and an opening into which the base of the sample support base can be inserted is formed.
The protractor for three-dimensional structure observation according to claim 4, wherein the protractor is assembled at a right angle to the base by inserting the base into the opening from the opposite surface side of the sample support member.

前記ベースの片面には、前記分度器の挿入限界を規制するストッパーが設けられている請求項１ないし請求項３のいずれかに記載の３次元構造観察用の試料支持台。 The sample support for observation of a three-dimensional structure according to any one of claims 1 to 3, wherein a stopper for restricting an insertion limit of the protractor is provided on one surface of the base.

前記ストッパーは、前記分度器を前記ベースの中心よりも前記試料支持部材の対向面側にて位置規制可能な位置に設けられている請求項６に記載の３次元構造観察用の試料支持台。 The sample support base for three-dimensional structure observation according to claim 6, wherein the stopper is provided at a position where the protractor can be regulated on the opposite surface side of the sample support member from the center of the base.

前記回転部材は、電子顕微鏡へ装着する際の奥行きを微調整する微動機構と、前記回転部材の回転軸に垂直な面内において前記回転部材位置を調整する第１の調整機構と、前記回転部材の電子顕微鏡鏡への装着角度を調整するための第２の調整機構と、によって回転軸が制御されており、
当該回転部材の先端部にホルダーを介して前記試料支持部材が設置されることで、常に試料が電子顕微鏡の視野中心に保持されるよう、電子線に対する試料の位置や角度が制御される請求項１ないし請求項３または請求項６ないし請求項７のいずれかに記載の３次元構造観察用の試料支持台。 The rotating member includes a fine adjustment mechanism for finely adjusting a depth when the rotating member is attached to the electron microscope, a first adjusting mechanism for adjusting the position of the rotating member in a plane perpendicular to a rotation axis of the rotating member, and the rotating member. The rotation axis is controlled by a second adjustment mechanism for adjusting the mounting angle to the electron microscope mirror,
The position and angle of the sample with respect to the electron beam are controlled such that the sample is always held at the center of the field of view of the electron microscope by installing the sample support member through a holder at the tip of the rotating member. A sample support for observing a three-dimensional structure according to any one of claims 1 to 3 or claims 6 to 7.

前記試料支持台は、前記試料支持部材の回転軸に対して直交する方向の回転軸を中心として回転自在であり、前記回転部材の傾斜軸と前記ベースの傾斜軸とによって２軸傾斜可能となっている請求１ないし請求項８のいずれかに記載の３次元構造観察用の試料支持台。 The sample support is rotatable about a rotation axis in a direction orthogonal to the rotation axis of the sample support member, and can be tilted in two axes by the tilt axis of the rotation member and the tilt axis of the base. The sample support for three-dimensional structure observation according to any one of claims 1 to 8.

基準姿勢から±一定角度範囲で回転可能な回転部材の先端部に、ベースと該ベースに対して回転自在に配された試料支持部材とを有する試料支持台を、ホルダーを介して設置し、
前記試料支持部材を前記ベースに対して一定角度間隔で段階的に回転させた複数の回転角度状態を維持させ、それぞれの回転角度状態において順次前記回転部材を±一定角度で回転させることで、試料を３６０°全方向から観察する電子顕微鏡における３次元構造観察方法。 A sample support base having a base and a sample support member that is rotatably arranged with respect to the base is installed via a holder at the tip of a rotating member that can rotate within a range of ± a certain angle from the reference posture.
By maintaining a plurality of rotation angle states in which the sample support member is rotated stepwise with respect to the base at a constant angle interval, the rotation member is sequentially rotated by ± a certain angle in each rotation angle state, Is a three-dimensional structure observation method in an electron microscope.

前記試料支持台に、一定角度間隔で複数の角度目盛りが印された分度器を組み付け、
前記試料支持部材の段階的な回転角度状態の変更を、前記試料支持部材の側面に設けられた指標を前記分度器の目盛りに合わせることで行う請求項１０に記載の３次元構造観察方法。
A protractor with a plurality of angular scales marked at regular angular intervals is assembled to the sample support,
The three-dimensional structure observation method according to claim 10, wherein the stepwise rotation angle state of the sample support member is changed by matching an index provided on a side surface of the sample support member with a scale of the protractor.