JP2533728C

JP2533728C -

Info

Publication number: JP2533728C
Authority: JP
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Publication date: 1999-11-22

Description

【発明の詳細な説明】【０００１】【産業上の利用分野】本発明は微小領域の３次元断面形状測定装置に係り、特に絶縁物表面の計測に
好適な微小領域の力を測定する装置に関する。【０００２】【従来の技術】従来、微小領域の力検出については、フィジカル、レビュー、レータ５６，（
１９８６年）第９３０頁から第９３３頁（Ｐｈｙｓ．Ｒｅｖ，Ｌｅｔｔ，
５６，（１９８６）ｐｐ９３０−９３３）において論じられている。【０００３】【発明が解決しようとする課題】上記従来技術は図２に示すごとく、はり支持具５により一端支点とされたはり
（板材）２の先端に鋭利な探針１を具備する。試料３の接近に伴なって、原子間
力によりはり２が変位し、該変位を走査型トンネル顕微鏡（ＳＴＭ）のごとくト
ンネル電流を一定に流し、はり２と探針１４との間隙を一定に保つことにより測
定する。このような非接触間隙測定方式を用いることで、力を変位に変換し、変
位を測定することによって微小領域の力検出が実行されていた。【０００４】この技術は、力検出のための探針１の剛性、及び変位測定のための安定性、即
ち、はり２の測定表面の表面粗さによる測定誤差の点について配慮がされておら
ず、検出精度に問題があった。【０００５】【課題を解決するための手段】上記の目的は、２つの支持部を有するはり部材と、はり部材に固定され２つの
支持部の間に位置する探針と、探針に対向して試料を配置する試料台と、探針と
試料の間隔を相対的に移動させる第１の移動手段と、探針を試料表面に沿って２
次元的に相対的に移動させる第２の移動手段と、探針と試料との間に働く力によ
るはり部材の変位を測定する測定手段とを有することによって達成される。【０００６】好適にははり部材の変位を一定に保つように第１の移動手段を制御しながら第
２の移動手段を動作させる制御装置を用いて３次元断面形状を測定する。【０００７】以上のように図２のはり２の剛性を向上するため、少なくともはり２の両端を
固定し、中央部に探針１を設置する。また、はり２の変位測定での表面凹凸による微小変位測定誤差を防止するため、大面積で微小変位を測定できる非接触変位
測定手段を設けることも望ましい。【０００８】【作用】両端支持のはり２は、両端支持のため探針軸方向に自由度を持ち、ねじれ等の
運動を防止することができる。このため、はり２の剛性が向上する。また、大面
積の変位検出部分を持つ非接触変位測定器ははり２表面の凹凸や原子の配列の影
響を受けることなく測定することができる。【０００９】【実施例】以下、本発明の一実施例を図１により説明する。図１は微小領域の３次元形状
測定器に本発明を応用した例を示す。【００１０】図１において、力の検出部ははり２の両端を支持具５で支持し、その中央部に
ダイヤモンド製の先端が非常に尖った探針１を設置し、はり２を介して探針１と
反対側に容量変位計のような非接触変位計４を設ける構造とした。【００１１】試料３は粗動機構１１の上に設けた３次元微動機構上の試料台６に搭載される
。３次元微動機構はＸ軸，Ｙ軸，Ｚ軸ピエゾ素子７，８，９を台座１０に図の様
に設置してトライポット型の構成としている。さらに、力による変位を検出して
、その力を一定、即ち、変位を一定にする様にＺ軸ピエゾ素子９を制御するとと
もに、２次元走査や探針１に試料３を近ずける粗動機構１１を制御する制御装置
１２を有する。表示装置１３は試料の３次元構造を３次元表示する。【００１２】はり２を厚さ１０μｍ，幅０．５ｃｍ，長さ５ｃｍの銀等で構成すると、約１
０^-12Ｎ（ニュートン）の力で約１Åの変化が生じる。一方、非接触変位測定手
段４には被測定部分が大面積である容量変位計、光てこ式の光学変位測定器が使
用される。また、粗動機構１１には尺取り虫機構やネジ式あるいは縮小変位機構
を使用したものを使用する。【００１３】上記の粗動機構１１により探針１に試料３を近接し、数Å程度までに接近する
と、双方の表面原子で最近接同士の原子間に力が働き、はり２の変位が起り、非
接触変位測定手段で検出される。この変化を一定に保つ様に制御装置１２でＺ軸
ピエゾ素子９を駆動し、探針１と試料３との間隙を一定に保つ。この状態を保ち
つつ、Ｘ軸，Ｙ軸ピエゾ素子７，８で２次元走査すると、試料３の表面形状に基
づいてＺ軸ピエゾ素子が変化して試料表面の３次元形状が得られ、表示装置１３
に微細構造を表示することができる。実際の原子間力は１０^-9〜１０^-10Ｎと言
われており、上述のはり構造及び変位計で十分、表面の原子構造を観察できる。【００１４】尚、本実施例は重力の影響を受けるような構成としたが、９０°回転し重力の
影響を受けない構成とすることもできる。また、微小機構や粗動機構を試料側あ
るいは力測定部に設置しても良い。探針１はダイヤモンド以外に硬度の高いもの
が良く、先端を鋭く尖らせることが重要であり、イオンエッチングや化学エッチ
ングあるいは精密加工技術によって製作されることが望ましい。さらに、探針を
絶縁物以外のものにすれば、走査型トンネル顕微鏡としても利用できる。【００１５】本システムは計算機と結合してデータ処理を行なうことにより、より良い像を
得ることができる。【００１６】【発明の効果】本発明によれば、探針の機械的剛性が増加し、力の影響を正確に変位に変換す
る。また、測定面積の大きい非接触変位測定手段を用いるため、はりの表面の凹
凸の影響を除くことができるので、高精度な微小部分の微小を検出することがで
きる。また、３次元形状測定器に応用することにより、全ての材料が測定可能と
なる。また、上記の非接触変位測定手段は通常、大気中で安定に動作するのでＳ
ＴＭのように真空中での動作の必要がなくなる。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring a three-dimensional sectional shape of a minute area, and more particularly to an apparatus for measuring force in a minute area suitable for measuring the surface of an insulator. . 2. Description of the Related Art Conventionally, regarding force detection in a minute area, a physical, a review, a translator 56, (
1986) pages 930 to 933 (Phys. Rev, Lett,
56, (1986) pp 930-933). As shown in FIG. 2, the prior art includes a sharp probe 1 at a tip of a beam (plate material) 2 which is supported at one end by a beam support 5. As the sample 3 approaches, the beam 2 is displaced by an atomic force, and the displacement is caused to flow a constant tunnel current as in a scanning tunneling microscope (STM), so that the gap between the beam 2 and the probe 14 is kept constant. Measure by keeping. By using such a non-contact gap measuring method, a force is converted into a displacement, and the displacement is measured to detect a force in a minute area. This technique does not take into account the rigidity of the probe 1 for force detection and the stability for displacement measurement, that is, measurement errors due to the surface roughness of the measurement surface of the beam 2. However, there was a problem in the detection accuracy. [0005] An object of the present invention is to provide a beam member having two support portions, a probe fixed to the beam member and located between the two support portions, and a probe facing the probe. A sample stage on which the sample is placed, first moving means for relatively moving the interval between the probe and the sample, and
This is achieved by having second moving means for relatively dimensionally moving and measuring means for measuring the displacement of the beam member due to the force acting between the probe and the sample. Preferably, a three-dimensional cross-sectional shape is measured using a control device that operates the second moving means while controlling the first moving means so as to keep the displacement of the beam member constant. As described above, in order to improve the rigidity of the beam 2 of FIG. 2, at least both ends of the beam 2 are fixed, and the probe 1 is installed at the center. Further, in order to prevent a small displacement measurement error due to surface irregularities in the displacement measurement of the beam 2, it is desirable to provide a non-contact displacement measuring means capable of measuring a small displacement over a large area. The beam 2 supported at both ends has a degree of freedom in the probe axis direction due to the support at both ends, and can prevent movement such as twisting. For this reason, the rigidity of the beam 2 is improved. Further, a non-contact displacement measuring instrument having a large area displacement detecting portion can measure without being affected by irregularities on the surface of the beam 2 and arrangement of atoms. An embodiment of the present invention will be described below with reference to FIG. FIG. 1 shows an example in which the present invention is applied to a three-dimensional shape measuring instrument for a minute area. In FIG. 1, a force detecting section supports both ends of a beam 2 with a support 5, and a probe 1 having a very sharp diamond tip is installed at the center thereof. A non-contact displacement meter 4 such as a capacitance displacement meter is provided on the opposite side of the needle 1. The sample 3 is mounted on a sample stage 6 on a three-dimensional fine movement mechanism provided on the coarse movement mechanism 11. The three-dimensional fine movement mechanism has a tri-pot type configuration in which X-, Y-, and Z-axis piezo elements 7, 8, and 9 are installed on a pedestal 10 as shown in the figure. Further, the displacement due to the force is detected, and the Z-axis piezo element 9 is controlled so as to keep the force constant, that is, the displacement. It has a control device 12 for controlling the mechanism 11. The display device 13 displays the three-dimensional structure of the sample three-dimensionally. When the beam 2 is made of silver or the like having a thickness of 10 μm, a width of 0.5 cm and a length of 5 cm, about 1
A force of 0 ^-12 N (Newton) produces a change of about 1 °. On the other hand, as the non-contact displacement measuring means 4, a capacitance displacement meter having a large area to be measured or an optical lever type optical displacement measuring device is used. As the coarse movement mechanism 11, a mechanism using a scale insect mechanism, a screw type or a reduction displacement mechanism is used. When the sample 3 is brought close to the probe 1 by the coarse movement mechanism 11 and is approached up to about several Å, a force acts between the nearest neighbor atoms on both surface atoms, and the displacement of the beam 2 occurs. Is detected by the non-contact displacement measuring means. The controller 12 drives the Z-axis piezo element 9 to keep this change constant, and keeps the gap between the probe 1 and the sample 3 constant. When two-dimensional scanning is performed by the X-axis and Y-axis piezo elements 7 and 8 while maintaining this state, the Z-axis piezo element changes based on the surface shape of the sample 3 to obtain a three-dimensional shape of the sample surface. 13
The fine structure can be displayed. The actual atomic force is said to be 10 ⁻⁹ to 10 ⁻¹⁰ N, and the beam structure and the displacement meter described above can sufficiently observe the atomic structure on the surface. Although the present embodiment is configured to be affected by gravity, it may be configured to rotate 90 ° and not be affected by gravity. Further, a minute mechanism or a coarse movement mechanism may be provided on the sample side or the force measuring unit. The probe 1 is preferably made of a material having a high hardness other than diamond, and it is important to sharpen the tip. It is desirable that the probe 1 be manufactured by ion etching, chemical etching, or precision processing technology. Further, if the probe is made of a material other than an insulator, it can be used as a scanning tunnel microscope. The present system can obtain a better image by performing data processing in combination with a computer. According to the present invention, the mechanical rigidity of the probe is increased, and the effect of the force is accurately converted to the displacement. Further, since the non-contact displacement measuring means having a large measuring area is used, the influence of the unevenness on the surface of the beam can be eliminated, so that a minute part of a minute part can be detected with high accuracy. Further, by applying the present invention to a three-dimensional shape measuring instrument, all materials can be measured. Further, since the above-mentioned non-contact displacement measuring means normally operates stably in the atmosphere, S
The need for operation in a vacuum unlike TM is eliminated.

【図面の簡単な説明】【図１】本発明の一実施例の構成を示す要部構成図。【図２】従来の力測定装置の原理的構成を示す要部構成図。【符号の説明】１…探針、２…はり、３…試料、４…測定面積の大きい非接触変位測定手段、
５…はり支持具、６…試料台、７…Ｘ軸ピエゾ素子、８…Ｙ軸ピエゾ素子、９…
Ｚ軸ピエゾ素子、１０…台座、１１…粗動機構、１２…制御回路、１３…表示手
段。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a main part configuration diagram showing a configuration of one embodiment of the present invention. FIG. 2 is a main part configuration diagram showing a principle configuration of a conventional force measuring device. [Description of Signs] 1 probe, 2 beam, 3 sample, 4 non-contact displacement measuring means with large measurement area,
5: beam support, 6: sample stage, 7: X-axis piezo element, 8: Y-axis piezo element, 9 ...
Z-axis piezo element, 10 pedestal, 11 coarse movement mechanism, 12 control circuit, 13 display means.

Claims

【特許請求の範囲】【請求項１】２つの支持部を有するはり部材と、該はり部材に固定され上記２つの支持部の
間に位置する探針と、該探針に対向して試料を配置する試料台と、上記探針と試
料の間隔を相対的に移動させる第１の移動手段と、上記探針を試料表面に沿って
２次元的に相対的に移動させる第２の移動手段と、上記はり部材の変位を探針の
配置された領域以外のはり部材の大面積の部分から測定する測定手段、前記はり
部材の変位を一定に保つように上記第１の移動手段を制御しながら前記第２の移
動手段を動作させる制御装置とを有するとともに、前記測定手段は光てこ式の光
学変位測定器であることを特徴とする３次元断面形状測定装置。【請求項２】２つの支持部を有するはり部材と、該はり部材に固定され上記２つの支持部の
間に位置する探針とを用い、該探針に対向して試料を配置し、上記探針を試料表
面に沿って２次元的に相対的に移動させるとともに、前記はり部材の変位を一定
に保つように制御しながら、前記探針を試料表面に沿って２次元的に相対的に移
動させ、上記はり部材の変位を探針の配置された領域以外のはり部材の大面積の
部分から光てこ式の光学変位測定器で前記はり部材の変位を測定することを特徴
とする３次元断面形状測定方法。【請求項３】前記試料台または探針を含む力測定部に、探針の試料表面に対する粗動機構お
よび／または微動機構が設けられた請求項１記載の３次元断面形状測定装置。Claims: 1. A beam member having two support portions, a probe fixed to the beam member and located between the two support portions, and a sample opposed to the probe. A sample stage to be arranged, first moving means for relatively moving the distance between the probe and the sample, and second moving means for relatively moving the probe two-dimensionally along the surface of the sample. Measuring means for measuring the displacement of the beam member from a large area portion of the beam member other than the area where the probe is arranged, while controlling the first moving means so as to keep the displacement of the beam member constant A control device for operating the second moving means, and the measuring means is an optical lever-type optical displacement measuring device. 2. Using a beam member having two support portions and a probe fixed to the beam member and located between the two support portions, arranging a sample opposite the probe, While moving the probe relatively two-dimensionally along the sample surface, and controlling the beam member to keep the displacement constant, the probe is relatively moved two-dimensionally along the sample surface. Moving the beam member from a large area portion of the beam member other than the area where the probe is arranged, and measuring the displacement of the beam member with an optical lever type optical displacement measuring instrument. Cross section shape measurement method. 3. The three-dimensional cross-sectional shape measuring apparatus according to claim 1, wherein a coarse movement mechanism and / or a fine movement mechanism with respect to the sample surface of the probe are provided in the force measuring section including the sample stage or the probe.