JPH06289036A - Cantilever and scanning force microscope - Google Patents
Cantilever and scanning force microscopeInfo
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- JPH06289036A JPH06289036A JP5072033A JP7203393A JPH06289036A JP H06289036 A JPH06289036 A JP H06289036A JP 5072033 A JP5072033 A JP 5072033A JP 7203393 A JP7203393 A JP 7203393A JP H06289036 A JPH06289036 A JP H06289036A
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- diffraction grating
- cantilever
- laser light
- light
- angle
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、カンチレバー及び走査
型フォース顕微鏡に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cantilever and a scanning force microscope.
【０００２】[0002]
【従来の技術】図５は従来の走査型フォース顕微鏡の構
成例である。近年、原子間力等の微細な力を測定するの
に走査型フォース顕微鏡が使われているが、この走査型
フォース顕微鏡にはカンチレバーが使われていた。この
カンチレバーは、端片が固定されていて、たわみができ
るような形になっている。測定したい試料とカンチレバ
ーの間に働く力の変化によってこのたわみの大きさが変
化する。このたわみの大きさの変化から、原子間力等を
測定していた。2. Description of the Related Art FIG. 5 shows a configuration example of a conventional scanning force microscope. In recent years, a scanning force microscope has been used to measure a fine force such as an atomic force, and a cantilever has been used in this scanning force microscope. This cantilever has a fixed end piece and is shaped so that it can be bent. The magnitude of this deflection changes according to the change in the force acting between the sample to be measured and the cantilever. Atomic force etc. were measured from the change in the size of the deflection.
【０００３】従来の走査型フォース顕微鏡は、主に光て
こ法と呼ばれる手法をもとに構成されていた。光てこ法
を用いた走査型フォース顕微鏡は、カンチレバー５１、
レーザー光源１３、二分割光検出器５２、およびＸＹＺ
走査装置２５からなる。以下に光てこ法を用いた走査型
フォース顕微鏡の動作を説明する。ＸＹＺ走査装置２５
によってカンチレバー５１を試料２４表面に接近させる
と、カンチレバー５１がたわむ。このたわみはカンチレ
バー５１の先端と試料２４表面との間に働く力（たとえ
ば原子間力）により生じるものである。ＸＹＺ走査装置
２５でカンチレバー５１を試料２４表面に沿って走査す
ると、カンチレバー５１の先端と試料２４表面との間に
働く力の変化に応じて、このたわみの大きさは変化す
る。このカンチレバー５１に、上方のレーザー光源１３
から出射されるレーザー光を入射して、カンチレバー５
１の表面で反射させると、そのたわみの大きさの変化に
より、カンチレバー５１表面へのレーザー光の入射角が
変化する。この入射角の変化によってカンチレバー５１
表面で反射する光の反射方向が変化する。この反射光を
二分割光検出器５２で検出する。反射方向の変化は二分
割光検出器５２の２つの光検出器からの信号強度の差の
変化として検出される。The conventional scanning force microscope was mainly constructed based on a technique called an optical lever method. The scanning force microscope using the optical lever method is a cantilever 51,
Laser light source 13, two-part photodetector 52, and XYZ
It comprises a scanning device 25. The operation of the scanning force microscope using the optical lever method will be described below. XYZ scanning device 25
When the cantilever 51 is brought close to the surface of the sample 24 by, the cantilever 51 bends. This deflection is caused by a force (for example, an atomic force) acting between the tip of the cantilever 51 and the surface of the sample 24. When the cantilever 51 is scanned along the surface of the sample 24 by the XYZ scanning device 25, the size of this deflection changes according to the change in the force acting between the tip of the cantilever 51 and the surface of the sample 24. To the cantilever 51, the upper laser light source 13
The laser light emitted from the cantilever 5 is incident on the cantilever 5.
When reflected on the surface of No. 1, the angle of incidence of the laser beam on the surface of the cantilever 51 changes due to the change in the size of the deflection. Due to this change in the incident angle, the cantilever 51
The reflection direction of the light reflected on the surface changes. This reflected light is detected by the two-divided photodetector 52. The change in the reflection direction is detected as a change in the difference in signal intensity from the two photodetectors of the two-split photodetector 52.
【０００４】上記方法により、試料２４表面とカンチレ
バー５１との間に働く力に対応した物理量を測定するの
が光てこ法を用いた走査型フォース顕微鏡である。たと
えば、原子間力を測定すれば試料の表面構造が、磁気力
を検出すれば表面の磁区分布が、そして、摩擦力を検出
すれば表面の摩擦分布が得られるわけである。上記のよ
うにして、従来の光てこ法を用いた走査型フォース顕微
鏡は、試料表面の微小領域における形状や摩擦力等の大
きさを測定していた。The scanning force microscope using the optical lever method measures the physical quantity corresponding to the force acting between the surface of the sample 24 and the cantilever 51 by the above method. For example, the surface structure of the sample can be obtained by measuring the atomic force, the magnetic domain distribution on the surface can be obtained by detecting the magnetic force, and the friction distribution on the surface can be obtained by detecting the frictional force. As described above, the conventional scanning force microscope using the optical lever method has measured the shape, the frictional force, and the like in a minute area on the surface of the sample.
【０００５】[0005]
【発明が解決しようとする課題】ところで、上記方法の
走査型フォース顕微鏡によれば、分解能は力を検出する
感度によって制限される。つまり、走査型フォース顕微
鏡の分解能は、二分割光検出器の二つの光検出器からの
信号の差（カンチレバーで反射した光の振れにより変化
する）で制限されるわけである。しかしながら、もとも
と局所的な原子間力、磁気力、摩擦力等は非常に小さ
く、カンチレバーのたわみも小さいので、レーザー光の
反射方向の変化も小さい。そのため、二分割光検出器の
二つの光検出器の信号の差も非常に小さくなり、分解能
がそれにより制限されるという問題点があった。By the way, according to the scanning force microscope of the above method, the resolution is limited by the sensitivity for detecting the force. That is, the resolution of the scanning force microscope is limited by the difference between the signals from the two photodetectors of the two-division photodetector (which changes due to the shake of the light reflected by the cantilever). However, since the local atomic force, magnetic force, frictional force, etc. are originally very small and the deflection of the cantilever is also small, the change in the reflection direction of laser light is also small. Therefore, there is a problem that the difference between the signals of the two photodetectors of the two-divided photodetector becomes very small, and the resolution is limited thereby.
【０００６】また、二分割光検出器の信号の差を大きく
して、分解能を高くするには、レーザー光の強度を増し
反射光量を増やすということも考えられるが、実際には
光検出器に入射される光量が約１０ｍＷ／ｃｍ2 を越え
ると飽和してしまうので、本質的な解決とはならない。
本発明は、上記問題点を考慮してなされたものであり、
分解能を高くすることができるカンチレバー及び走査型
フォース顕微鏡を提供することを目的とする。Further, in order to increase the difference between the signals of the two-divided photodetector and increase the resolution, it is conceivable to increase the intensity of the laser light and increase the amount of reflected light. If the amount of incident light exceeds about 10 mW / cm 2 , it will be saturated, so this is not an essential solution.
The present invention has been made in consideration of the above problems,
An object of the present invention is to provide a cantilever and a scanning force microscope capable of increasing the resolution.
【０００７】[0007]
【課題を解決するための手段】上記課題の解決のため、
本発明のカンチレバーはレーザー光を入射する面に回折
格子を形成する構成とした。また、本発明の走査型フォ
ース顕微鏡は、レーザー光を出射する光源と、前記レー
ザー光を入射する面に回折格子を形成してあるカンチレ
バーと、試料表面に対する前記カンチレバーとの位置を
変える走査手段と、前記回折格子面からの前記レーザー
光の１次以上の回折光の変化を検出する検出手段とを有
し、前記レーザー光の前記回折格子への入射方向と前記
回折格子面の法線方向とのなす角θと前記レーザー光の
前記回折格子面からの１次以上の回折光の出射方向と前
記回折格子面の法線方向とのなす角φがｃｏｓθ／ｃｏ
ｓφ＞１を満たす構成とした。[Means for Solving the Problems] In order to solve the above problems,
The cantilever of the present invention has a structure in which a diffraction grating is formed on the surface on which laser light is incident. Further, the scanning force microscope of the present invention comprises a light source that emits laser light, a cantilever having a diffraction grating formed on a surface on which the laser light is incident, and a scanning unit that changes the position of the cantilever with respect to the sample surface. A detecting means for detecting a change in first-order or higher-order diffracted light of the laser light from the diffraction grating surface, and an incident direction of the laser light to the diffraction grating and a normal direction of the diffraction grating surface. And the angle φ formed by the emission direction of the first or higher order diffracted light from the diffraction grating surface of the laser light and the normal direction of the diffraction grating surface is cos θ / co
The configuration is such that sφ> 1 is satisfied.
【０００８】[0008]
【作用】以下図１ａに基づいて本発明のカンチレバー１
１の表面に回折格子１２を形成し、レーザー光源１３に
よって出射されたレーザー光を、カンチレバー１１表面
に入射したときのそのレーザー光の出射の様子を示す。
図１ａ記載の矢印Ａは正反射光（０次の回折光）を示
し、矢印Ｂは１次以上の回折光を示す。また、回折格子
１２面の法線方向はＺ軸と同一である。The cantilever 1 of the present invention will now be described with reference to FIG. 1a.
A diffraction grating 12 is formed on the surface of No. 1 and a laser beam emitted from a laser light source 13 when the laser beam is incident on the surface of the cantilever 11 is shown.
Arrow A in FIG. 1A indicates specularly reflected light (0th order diffracted light), and arrow B indicates 1st or higher order diffracted light. The normal direction of the diffraction grating 12 surface is the same as the Z axis.
【０００９】レーザー光源１３から出射されるレーザー
光がカンチレバー１１の表面に入射する入射方向と回折
格子１２面の法線方向とのなす角を入射角θとして、回
折格子１２からの０次の回折光（正反射光）の出射方向
と回折格子１２面の法線方向とのなす角を出射角θ0 と
して、回折格子１２からの１次以上の回折光の出射方向
と回折格子１２面の法線方向とのなす角を出射角φとす
る。The 0th-order diffraction from the diffraction grating 12 is defined as the angle of incidence between the incident direction of the laser light emitted from the laser light source 13 on the surface of the cantilever 11 and the normal direction of the surface of the diffraction grating 12. The angle between the emission direction of light (regularly reflected light) and the normal line direction of the diffraction grating 12 surface is defined as an emission angle θ 0 , and the emission direction of the first or higher order diffracted light from the diffraction grating 12 and the normal direction of the diffraction grating 12 surface. The angle formed by the line direction is the emission angle φ.
【００１０】波長λのレーザー光が回折格子１２に入射
角θで入射したとき、０次光の出射角θ0 はもちろん角
度θの値となるが、そのほかに１次、２次、・・・、ｎ
次の回折光が生成される。ｎの上限は、入射角θ、回折
格子１２の格子間隔ｄ、レーザー光の波長λで決まる。
たとえば、λ＝６７０ｎｍ、ｄ＝１／１２００ｍｍの場
合には、ｎの最大は２である。When a laser beam of wavelength λ is incident on the diffraction grating 12 at an incident angle θ, the exit angle θ 0 of 0th order light is of course the value of the angle θ, but in addition to that, the primary, secondary, ... , N
The next diffracted light is generated. The upper limit of n is determined by the incident angle θ, the grating spacing d of the diffraction grating 12, and the wavelength λ of the laser light.
For example, when λ = 670 nm and d = 1/1200 mm, the maximum value of n is 2.
【００１１】１次以上の回折光の出射角φ、レーザー光
の入射角θ、回折格子の間隔ｄ、およびレーザー光の波
長λとの間には、次のような関係がある。 ｄ（ｓｉｎφ−ｓｉｎθ）＝ｋλ ただし、ｋ＝１、２、・・・、ｎ ∴ｓｉｎφ＝ｋλ／ｄ＋ｓｉｎθ ・・・（１） このときに入射角がθからθ＋Δθに変化したときの出
射角の変化Δφを求めると、 Δφ＝Δθ・ｃｏｓθ／ｃｏｓφ ・・・（２） 実際にこのカンチレバー１１に本発明の光てこ法を適用
したときは、カンチレバー１１の回折格子面１２がΔθ
傾き入射光の方向が変化するので、実際に観察される回
折光の振れ角は、 Δθ＋Δφ＝Δθ・（１＋ｃｏｓθ／ｃｏｓφ） ・・・（３） となる。ここで、従来の技術では、カンチレバー１１面
がΔθ傾き入射光の方向が変化すると、反射方向の出射
角の変化もΔθ変化するので実際に二分割光検出器１４
で検出される反射光の変化は２Δθになる。There is the following relationship among the exit angle φ of the diffracted light of the first order and above, the incident angle θ of the laser light, the spacing d of the diffraction grating, and the wavelength λ of the laser light. d (sin φ-sin θ) = kλ where k = 1, 2, ..., N ∴sin φ = kλ / d + sin θ (1) At this time, the angle of emission when the incident angle changes from θ to θ + Δθ When the change Δφ is obtained, Δφ = Δθ · cos θ / cos φ (2) When the optical lever method of the present invention is actually applied to this cantilever 11, the diffraction grating surface 12 of the cantilever 11 is Δθ.
Since the direction of the obliquely incident light changes, the deflection angle of the diffracted light that is actually observed is Δθ + Δφ = Δθ · (1 + cosθ / cosφ) (3). Here, in the conventional technique, when the surface of the cantilever 11 is inclined by Δθ and the direction of the incident light is changed, the change of the emission angle in the reflection direction is also changed by Δθ.
The change in the reflected light detected at is 2Δθ.
【００１２】そこで、本発明においては、（１）式、
（２）式から、ｃｏｓθ／ｃｏｓφ＞１を満たすように
回折格子の格子間隔ｄとレーザー光の波長λと入射角θ
を選ぶことにより、Δθ＋Δφ＞２Δθとなり、従来よ
り分解能の高い走査型フォース顕微鏡を得ることができ
る。このとき、本発明の走査型フォース顕微鏡で観察さ
れるカンチレバーと試料表面との間に働く力は、たとえ
ば原子間力、摩擦力、静電気力、磁気力、マクスウェル
応力等である。Therefore, in the present invention, the equation (1)
From the equation (2), the grating spacing d of the diffraction grating, the wavelength λ of the laser light and the incident angle θ are set so as to satisfy cos θ / cos φ> 1.
By selecting, Δθ + Δφ> 2Δθ, and a scanning force microscope with higher resolution than in the past can be obtained. At this time, the force acting between the cantilever and the sample surface observed with the scanning force microscope of the present invention is, for example, atomic force, frictional force, electrostatic force, magnetic force, Maxwell stress, or the like.
【００１３】[0013]
【実施例１】図２は本発明の第１の実施例による原子間
力顕微鏡である。図２に示すように、原子間力を検出す
るためのカンチレバー２１は上面にカンチレバー長手方
向と直角に回折格子２２を形成しておく。そしてＸＹＺ
走査装置２５で試料２４表面を走査できるようになって
いる。Embodiment 1 FIG. 2 is an atomic force microscope according to the first embodiment of the present invention. As shown in FIG. 2, the cantilever 21 for detecting the atomic force has a diffraction grating 22 formed on the upper surface at a right angle to the longitudinal direction of the cantilever. And XYZ
The surface of the sample 24 can be scanned by the scanning device 25.
【００１４】回折格子２２面の法線方向とレーザー光源
１３からの入射光線を含む面が、回折格子２２を形成し
てある方向に対しほぼ直交するようにレーザー光源１３
を配置する。回折格子２２から出射される一次の回折光
は、カンチレバー２１のたわみによって、回折格子２２
面に対する法線方向と出射光線を含む面内を動く。そこ
で、二分割光検出器２３は、その平面と二分割光検出器
２３内の２つの光検出器の分割線が直交するように配置
する。この２つの光検出器からのそれぞれの出力信号は
差動増幅器２７に入力され、作動増幅器２７で二つの信
号の差をとり、その差信号を増幅して出力される。この
差動増幅器２７からの差信号は信号処理装置２８に入力
される。走査制御装置２６からの信号はＸＹＺ走査制御
装置２５にも入力される。The laser light source 13 is arranged so that the direction normal to the surface of the diffraction grating 22 and the surface containing the incident light from the laser light source 13 are substantially orthogonal to the direction in which the diffraction grating 22 is formed.
To place. The first-order diffracted light emitted from the diffraction grating 22 is deflected by the cantilever 21 so that the diffraction grating 22
It moves in the plane containing the outgoing ray and the direction normal to the plane. Therefore, the two-part photodetector 23 is arranged so that its plane and the dividing line of the two photodetectors in the two-part photodetector 23 are orthogonal to each other. The respective output signals from these two photodetectors are input to the differential amplifier 27, the difference between the two signals is calculated by the operational amplifier 27, and the difference signal is amplified and output. The difference signal from the differential amplifier 27 is input to the signal processing device 28. The signal from the scan controller 26 is also input to the XYZ scan controller 25.
【００１５】試料２４表面の上方からＸＹＺ走査装置２
５を用いてカンチレバー２１を接近させる。このときの
試料２４表面とカンチレバー２１との距離は原子間力が
検出できる程度とする。レーザー光源１３から出射され
るレーザー光は、不図示の光学系等によりカンチレバー
２１上面の回折格子２２に完全に焦点を結ばない程度
（光のスポット径を回折格子の格子間隔の１０倍より大
きくする）に入射される。このとき、回折格子２２面で
光の回折が起こるが、その一次の回折光を二分割光検出
器２３に入射する。From above the surface of the sample 24, the XYZ scanning device 2
5 is used to bring the cantilever 21 closer. At this time, the distance between the surface of the sample 24 and the cantilever 21 is set so that the interatomic force can be detected. The laser light emitted from the laser light source 13 is not completely focused on the diffraction grating 22 on the upper surface of the cantilever 21 by an unillustrated optical system or the like (the spot diameter of the light is made larger than 10 times the grating interval of the diffraction grating). ) Is incident on. At this time, light is diffracted on the surface of the diffraction grating 22, and the first-order diffracted light is incident on the two-split photodetector 23.
【００１６】試料２４表面からカンチレバー２１が受け
る原子間力に応じてカンチレバー２１には反る形のたわ
みが生じる。試料２４表面上をＸＹＺ走査装置２５によ
ってカンチレバー２１で相対的に走査することにより、
このたわみの大きさは変化する。このたわみの大きさの
変化に応じてレーザー光の入射角は変化する。この入射
角の変化は、上述の一次回折光を偏向させ、作動増幅器
２７からの差信号の変化としてとらえられる。この差信
号は、走査制御装置２６からのカンチレバーをどの様に
走査したかという走査信号情報と共に、信号処理装置２
８に送られ、図示しない表示装置に表示されるなど信号
処理が行われ、たとえば画像の再構成が行われる。The cantilever 21 is warped in accordance with the atomic force received by the cantilever 21 from the surface of the sample 24. By relatively scanning the surface of the sample 24 with the cantilever 21 by the XYZ scanning device 25,
The magnitude of this deflection changes. The incident angle of the laser light changes according to the change in the size of the deflection. This change in the incident angle deflects the above-described first-order diffracted light, and can be captured as a change in the difference signal from the operational amplifier 27. This difference signal, together with the scanning signal information indicating how the cantilever is scanned from the scanning control device 26, together with the signal processing device 2
Then, signal processing such as display on a display device (not shown) is performed, and image reconstruction is performed, for example.
【００１７】さらに、この得られた差信号が一定になる
ようにＸＹＺ走査装置２５にフィードバックをかけるな
どして、高さ方向に制御を行なってもよい。この場合
は、この制御信号を高さ方向の信号処理の対象とする。
レーザー光がどの様な位置から回折格子に入射される
か、または、レーザー光が、入射した回折格子からどの
様な位置に出射されるかは次の２つの角できまる。１つ
は、入射及び出射される面の法線方向と、入射方向又は
出射方向とのなす角である。もう１つは、入射光又は出
射光をＸＹ面（回折格子面）に垂直に投影した投影線
と、Ｘ軸又はＹ軸とのなす角である。Further, control may be performed in the height direction by giving feedback to the XYZ scanning device 25 so that the obtained difference signal becomes constant. In this case, this control signal is targeted for signal processing in the height direction.
The following two angles determine the position of the laser light entering the diffraction grating or the position of the laser light exiting from the incident diffraction grating. One is the angle between the normal direction of the incident and outgoing surfaces and the incident or outgoing direction. The other is the angle formed by the X-axis or the Y-axis and the projection line obtained by projecting the incident light or the emitted light perpendicularly to the XY plane (diffraction grating surface).
【００１８】図１ａに示すように、カンチレバー１１の
長手方向にＸ軸をとり、カンチレバー１１の長軸方向に
垂直にＹ軸をとり、カンチレバー１１の法線方向にＺ軸
をとる。このＺ軸は、カンチレバー１１表面及び回折格
子１２面の法線方向と同一であり、ＸＹ平面は、カンチ
レバー１１表面及び回折格子１２面と同一である。ま
た、Ｘ軸、Ｙ軸、Ｚ軸は、レーザー光１３が回折格子１
２に入射及び出射する点でそれぞれ直交していて、矢印
の方向を正とする。入射光及び出射光をＸＹ面に垂直に
投影したものを以下入射光の投影線及び出射光の投影線
と呼ぶ。図１ａでは、Ｘ軸と入射光の投影線及び反射光
の投影線は同一軸上にある。図１ｂは紙面の上側がＺ軸
の正の方向でありＸＹ平面を垂直に見た図である。図１
ｂに示す様に、Ｘ軸の正の方向から角度をはかり、矢印
Ｃの方向の角を正として、矢印Ｃと逆の方向の角を負と
する。以下例えば、入射光がＸＹ平面のＸ軸から４５度
で入射する、と記したとき、これは、入射光の投影線と
Ｘ軸とのなす角がＸ軸の正の方向から矢印Ｃの方向に４
５度の角度をなして、その方向から入射することを示
す。出射光の場合も、例えば、出射光がＸＹ平面のＸ軸
から４５度で出射する、と記したとき、これは、出射光
の投影線とＸ軸とのなす角がＸ軸の正の方向から矢印Ｃ
の方向に４５度の角度をなして、その方向へ出射するこ
とを示す。As shown in FIG. 1A, the X axis is taken in the longitudinal direction of the cantilever 11, the Y axis is taken perpendicularly to the long axis direction of the cantilever 11, and the Z axis is taken in the normal direction of the cantilever 11. The Z axis is the same as the normal direction of the surface of the cantilever 11 and the diffraction grating 12 surface, and the XY plane is the same as the surface of the cantilever 11 and the diffraction grating 12 surface. The laser beam 13 is used for the X-axis, Y-axis, and Z-axis of the diffraction grating 1.
2 are orthogonal to each other at the points of incidence and emission, and the direction of the arrow is positive. The projections of the incident light and the outgoing light perpendicular to the XY plane are hereinafter referred to as the incident light projection line and the outgoing light projection line. In FIG. 1a, the X axis and the incident light projection line and the reflected light projection line are on the same axis. FIG. 1b is a view in which the upper side of the paper surface is the positive direction of the Z axis and the XY plane is viewed vertically. Figure 1
As shown in b, the angle is measured from the positive direction of the X axis, the angle in the direction of arrow C is positive, and the angle in the direction opposite to arrow C is negative. Hereinafter, for example, when it is described that the incident light is incident at 45 degrees from the X axis of the XY plane, this means that the angle between the projection line of the incident light and the X axis is from the positive direction of the X axis to the direction of arrow C. To 4
It shows that the light is incident from that direction at an angle of 5 degrees. In the case of emitted light, for example, when it is noted that the emitted light is emitted at 45 degrees from the X axis of the XY plane, this means that the angle between the projection line of the emitted light and the X axis is the positive direction of the X axis. From arrow C
It indicates that the light is emitted in that direction at an angle of 45 degrees.
【００１９】本実施例においては、例えば、回折格子２
２の格子間隔ｄを１／１２００ｍｍとして、レーザー光
源１３のレーザー光の波長λを６７０ｎｍにして、レー
ザー光の入射方向と回折格子２２面の法線方向との角度
θが８．０度でＸＹ平面のＸ軸から１８０度になるよう
にレーザー光源１３からのレーザー光を入射すると、一
次の回折光は出射方向と回折格子２２面の法線方向との
角度φが７０．７度でＸＹ平面のＸ軸から０度になるよ
うに出射する。In the present embodiment, for example, the diffraction grating 2
The grating spacing d of 2 is 1/1200 mm, the wavelength λ of the laser light of the laser light source 13 is 670 nm, and the angle θ between the incident direction of the laser light and the normal direction of the diffraction grating 22 surface is 8.0 degrees. When the laser light from the laser light source 13 is incident so as to be 180 degrees from the X-axis of the plane, the first-order diffracted light has an angle φ between the emitting direction and the normal direction of the diffraction grating 22 surface of 70.7 degrees and the XY plane. The light is emitted from the X axis at 0 degree.
【００２０】この時、カンチレバー２１がたわんだとき
の一次の回折光の出射方向の変化は、０次光の場合の変
化に比べて、約２．０倍の大きさになる。従ってこれに
相当した分解能の向上が得られる。尚、回折格子２２を
形成してある面の反射率は一般にそうでない鏡面に比べ
ると低い傾向があるが、回折格子作製時に回折格子にブ
レーズ角を付けておけば、用いる回折光を金属膜の正反
射と遜色ない程度まで高めることができる。このことに
より、Ｓ／Ｎの悪化を防止できる。At this time, the change in the emission direction of the first-order diffracted light when the cantilever 21 bends is about 2.0 times as large as the change in the case of the zero-order light. Therefore, a corresponding improvement in resolution can be obtained. Incidentally, the reflectance of the surface on which the diffraction grating 22 is formed generally tends to be lower than that of a mirror surface which is not so. It can be increased to the level comparable to regular reflection. This can prevent the deterioration of S / N.
【００２１】本実施例ではＸ、Ｙ、Ｚ方向に走査するた
めにカンチレバーを動かしているが、試料をＸ、Ｙ、Ｚ
方向に動かしても良い。また、カンチレバー２１先端付
近下面にピラミッド型の針が形成してあるが、これはな
くてもよい。本実施例では１次の回折光を使用している
が、これは他の次数の回折光を使用してもよい。In this embodiment, the cantilever is moved for scanning in the X, Y, Z directions, but the sample is moved in the X, Y, Z directions.
You can move it in any direction. Further, although a pyramid-shaped needle is formed on the lower surface near the tip of the cantilever 21, this may be omitted. Although the diffracted light of the first order is used in this embodiment, diffracted light of other orders may be used.
【００２２】また、カンチレバー２１の先端を磁化させ
ておき、カンチレバー２１と試料２４表面との間に働く
力が主に磁気力であるようにすれば、走査型磁気力顕微
鏡を構成することもでき、カンチレバー２１と試料２４
表面との間に働く力が主に静電気力にすれば走査型静電
気力顕微鏡ができ、これらも同様に従来型のものよりも
分解能を高めることができる。If the tip of the cantilever 21 is magnetized so that the force acting between the cantilever 21 and the surface of the sample 24 is mainly a magnetic force, a scanning magnetic force microscope can be constructed. , Cantilever 21 and sample 24
If the force acting between the surface and the surface is mainly electrostatic force, a scanning electrostatic force microscope can be obtained, and these can similarly have higher resolution than the conventional type.
【００２３】[0023]
【実施例２】第２の実施例による摩擦力顕微鏡を図３に
示す。摩擦力を検出するカンチレバー３１には図３に示
すように上面に長手方向と平行に回折格子３２を形成し
ておく。そして、ＸＹＺ走査装置２５で試料２４表面を
走査できるようになっている。Second Embodiment A frictional force microscope according to the second embodiment is shown in FIG. As shown in FIG. 3, a diffraction grating 32 is formed on the upper surface of the cantilever 31 for detecting the frictional force in parallel with the longitudinal direction. Then, the surface of the sample 24 can be scanned by the XYZ scanning device 25.
【００２４】回折格子３２面の法線方向とレーザー光源
１３からの入射光線を含む面が、回折格子３２を形成し
てある方向に対してほぼ直角となるようにレーザー光源
１３をおく。回折格子３２から出射される一次の回折光
は回折格子３２面の法線方向と出射光線を含む面内を動
く。そこで、二分割光検出器３３は、その平面と二分割
光検出器３３内の２つの光検出器の分割線が直交するよ
うに配置する。The laser light source 13 is placed so that the direction normal to the surface of the diffraction grating 32 and the surface containing the incident light beam from the laser light source 13 are substantially perpendicular to the direction in which the diffraction grating 32 is formed. The first-order diffracted light emitted from the diffraction grating 32 moves in the normal direction of the surface of the diffraction grating 32 and in the plane including the emitted light beam. Therefore, the two-part photodetector 33 is arranged so that its plane and the dividing line of the two photodetectors in the two-part photodetector 33 are orthogonal to each other.
【００２５】試料２４表面から受ける摩擦力に応じてカ
ンチレバー３１には、ねじれるようにたわみが生じる。
試料２４表面上をＸＹＺ走査制御装置２５によってカン
チレバー３１をその長手方向と直交する方向に走査した
ときこのたわみの大きさは変化する。本実施例において
は、例えば、回折格子３２の格子間隔ｄを１／１２００
ｍｍとして、レーザー光源１３のレーザー光の波長λを
６７０ｎｍにして、レーザー光源１３からの入射方向と
回折格子３２面の法線方向との角度θが８．０度でＸＹ
平面のＸ軸から２７０度になるようにレーザー光を入射
すると、一次の回折光は出射光線と回折格子３２面の法
線方向との角度φが７０．７度でＸＹ平面のＸ軸から９
０度になるように出射する。The cantilever 31 is twisted and bent in response to the frictional force received from the surface of the sample 24.
When the XYZ scanning control device 25 scans the surface of the sample 24 with the cantilever 31 in a direction orthogonal to its longitudinal direction, the magnitude of this deflection changes. In the present embodiment, for example, the grating spacing d of the diffraction grating 32 is 1/1200.
mm, the wavelength λ of the laser light of the laser light source 13 is 670 nm, and the angle θ between the incident direction from the laser light source 13 and the normal direction of the diffraction grating 32 surface is 8.0 degrees.
When the laser light is incident so as to be 270 degrees from the X axis of the plane, the first-order diffracted light has an angle φ of 70.7 degrees between the outgoing ray and the normal line direction of the diffraction grating 32 surface and is 9 degrees from the X axis of the XY plane.
Emit so that it becomes 0 degree.
【００２６】この時、カンチレバー３１がたわんだとき
の一次の回折光の出射方向の変化は、０次光の場合の変
化に比べて、約２．０倍の大きさになる。従ってこれに
相当した分解能の向上が得られる。他の構成は実施例１
と同様である。At this time, the change in the emission direction of the first-order diffracted light when the cantilever 31 bends is about 2.0 times as large as the change in the case of the zero-order light. Therefore, a corresponding improvement in resolution can be obtained. The other configuration is the first embodiment.
Is the same as.
【００２７】[0027]
【実施例３】第３の実施例による原子間力・摩擦力顕微
鏡を図４に示す。原子間力及び摩擦力を検出するカンチ
レバー４１には図４に示すように上面にカンチレバー４
１の長軸方向にたいし、平行と直角に回折格子４２を形
成しておく。Third Embodiment FIG. 4 shows an atomic force / friction force microscope according to a third embodiment. As shown in FIG. 4, the cantilever 41 for detecting the atomic force and the frictional force has an upper surface, as shown in FIG.
The diffraction grating 42 is formed in parallel with the direction of the long axis of 1 at a right angle.
【００２８】回折格子４２面の法線方向とレーザー光源
１３からの入射光線を含む面が、回折格子４２のＸＹ平
面にＸ軸から−４５度の角度で入射するようにレーザー
光源１３を配置する。ここで、カンチレバーの長手方向
に直角な回折格子による回折光の次数をＭとして、カン
チレバーの長手方向に平行な回折格子による回折光の次
数をＮとするとき、以下これを（Ｍ，Ｎ）次と記す。The laser light source 13 is arranged such that the normal direction of the surface of the diffraction grating 42 and the surface containing the incident light from the laser light source 13 are incident on the XY plane of the diffraction grating 42 at an angle of −45 degrees from the X axis. . Here, when the order of the diffracted light by the diffraction grating perpendicular to the longitudinal direction of the cantilever is M and the order of the diffracted light by the diffraction grating parallel to the longitudinal direction of the cantilever is N, this is expressed as (M, N) Is written.
【００２９】レーザー光源１３により回折格子４２に光
が入射すると、回折格子４２面で光の回折が起こるが、
その（１，０）次の回折光が二分割光検出器４３に入射
され、（０，１）次の回折光が二分割光検出器４４に入
射されるように、二分割光検出器４３、４４を配置す
る。この時、回折格子からの出射光は、原子間力を感じ
たとき実施例１と同様な動き方をし、摩擦力を感じたと
き実施例２と同様な動き方をする。したがって、２分割
光検出器４３の２つの光検出器の分割線を実施例１と同
様に、２分割光検出器４４の２つの光検出器の分割線を
実施例２と同様になるように配置する。それぞれの２分
割光検出器の２つの検出器からの信号はそれぞれ差動増
幅器４５、４６に入力される。差動増幅器４５、４６は
入力された２つの信号レベルの差をとり、その差信号を
増幅して出力する。この差動増幅器４５、４６からの差
信号は信号処理装置２８に入力される。走査制御装置２
６からの信号はＸＹＺ走査制御装置２５にも入力され
る。When light is incident on the diffraction grating 42 by the laser light source 13, light is diffracted on the surface of the diffraction grating 42.
The (1,0) -th order diffracted light enters the two-split photodetector 43, and the (0,1) -th order diffracted light enters the two-split photodetector 44. , 44 are arranged. At this time, the emitted light from the diffraction grating moves in the same manner as in Example 1 when an interatomic force is felt, and moves in the same manner as in Example 2 when a frictional force is felt. Therefore, the dividing line of the two photodetectors of the two-divided photodetector 43 should be the same as that of the first embodiment, and the dividing line of the two photodetectors of the two-divided photodetector 44 should be the same as that of the second embodiment. Deploy. The signals from the two detectors of the two-divided photodetectors are input to the differential amplifiers 45 and 46, respectively. The differential amplifiers 45 and 46 take the difference between the two input signal levels, amplify the difference signal, and output it. The difference signals from the differential amplifiers 45 and 46 are input to the signal processing device 28. Scan control device 2
The signal from 6 is also input to the XYZ scan controller 25.
【００３０】試料２４表面上を、ＸＹＺ走査制御装置２
５を用いて、カンチレバー４１をその長手方向と直交す
る方向に走査したとき、カンチレバー４１には、試料２
４表面から受ける原子間力によって実施例１と同様な反
りの方向のたわみが生じる。このたわみの大きさの変化
は、主に二分割光検出器４３で検出される。この二分割
光検出器４３からの信号は原子間力によるものであるた
め、走査制御装置２６からの走査信号情報とともに、信
号処理装置２８に送り、図示しない表示装置に表示され
るなど信号処理を行なえば、原子間力分布画像が得られ
る。On the surface of the sample 24, the XYZ scanning control device 2
5, when the cantilever 41 was scanned in a direction orthogonal to its longitudinal direction, the sample 2 was
4 Deflection in the direction of warpage similar to that in Example 1 occurs due to the interatomic force received from the surface. The change in the size of the deflection is mainly detected by the two-part photodetector 43. Since the signal from the two-divided photodetector 43 is due to the interatomic force, it is sent to the signal processing device 28 together with the scanning signal information from the scanning control device 26, and is subjected to signal processing such as being displayed on a display device (not shown). If done, an atomic force distribution image can be obtained.
【００３１】一方、摩擦力によってもカンチレバー４１
はたわむ。このたわみは、実施例２と同様にねじれるよ
うに生じる。このたわみの大きさの変化は、主に二分割
光検出器４４で検出される。この二分割光検出器４４か
らの信号は摩擦力によるものであるため、走査制御装置
２６からの走査信号情報とともに、信号処理装置２８に
送り、図示しない表示装置に表示されるなど信号処理を
行なえば、摩擦力分布画像が得られる。On the other hand, the cantilever 41 is also caused by frictional force.
I bend. This flexure is twisted as in the second embodiment. This change in the size of the deflection is mainly detected by the two-part photodetector 44. Since the signal from the two-divided photodetector 44 is due to frictional force, it is sent to the signal processing device 28 together with the scanning signal information from the scanning control device 26 so that signal processing such as display on a display device (not shown) can be performed. Thus, a frictional force distribution image can be obtained.
【００３２】得られた二種類の信号あるいは二種類の画
像は、試料の同一の領域における原子間力と摩擦力の情
報であり、比較することにより試料２４表面における形
状と摩擦すなわち吸着性との情報が同時に得られる。本
実施例において、二分割光検出器４３に摩擦力の信号が
ノイズとして入ることがあるが、二分割光検出器４４か
らの信号を用いて補正をすることができる。また、二分
割光検出器４４に原子間力の信号がノイズとして入るこ
とがあるが、二分割光検出器４３からの信号を用いて補
正をすればよい。The obtained two kinds of signals or two kinds of images are information of the atomic force and the frictional force in the same region of the sample, and by comparison, the shape and the friction, that is, the adsorptive property on the surface of the sample 24 are compared. Information is obtained at the same time. In the present embodiment, the frictional force signal may enter the two-divided photodetector 43 as noise, but the signal from the two-divided photodetector 44 can be used for correction. Further, the signal of the interatomic force may enter the two-divided photodetector 44 as noise, but the signal from the two-divided photodetector 43 may be used for correction.
【００３３】さらに、原子間力の信号強度が一定になる
ようにＸＹＺ走査装置２５にフィードバックをかけるこ
とにより、試料２４表面からのプローブの高さを一定に
したまま摩擦力の測定をすることもできる。本実施例に
おいて、例えば、回折格子４２の格子間隔ｄを１／１２
００ｍｍとして、レーザー光源１３のレーザー光の波長
λを６７０ｎｍにして、レーザー光源１３からの入射方
向がＸＹ平面の法線方向から１３．０度で、ＸＹ平面の
Ｘ軸から−４５度になるように入射する。この時、
（１，０）次の回折光は、ＸＹ平面のＸ軸から９．４度
の角度で、ＸＹ平面の法線方向と（１，０）次の回折光
とのなす角が７７．５度で出射され、（０，１）次の回
折光はＸＹ平面のＸ軸から８０．６度の角度で、ＸＹ平
面の法線方向と（０，１）次の回折光とのなす角が７
７．５度で出射される。Further, by feeding back the XYZ scanning device 25 so that the signal intensity of the atomic force becomes constant, the frictional force can be measured while the height of the probe from the surface of the sample 24 is constant. it can. In this embodiment, for example, the grating spacing d of the diffraction grating 42 is set to 1/12.
The laser light source 13 has a wavelength λ of 670 nm and the incident direction from the laser light source 13 is 13.0 degrees from the normal direction of the XY plane and −45 degrees from the X axis of the XY plane. Incident on. At this time,
The (1,0) th order diffracted light is at an angle of 9.4 degrees from the X axis of the XY plane, and the angle between the normal direction of the XY plane and the (1,0) th order diffracted light is 77.5 degrees. And the (0,1) -th order diffracted light is at an angle of 80.6 degrees from the X-axis of the XY plane, and the angle between the normal direction of the XY plane and the (0,1) -th order diffracted light is 7
It is emitted at 7.5 degrees.
【００３４】ＸＺ平面に垂直に投影した入射方向と法線
方向との角度θは９．２０度であり、ＸＺ平面に垂直に
投影した（１，０）次の回折光の出射方向と法線方向と
の角度φは７７．３度になる。また、ＹＺ平面に垂直に
投影した入射方向と法線方向との角度θは９．２０度で
あり、ＹＺ平面に垂直に投影した（０，１）次の回折光
の出射方向と法線方向との角度φは７７．３度になる。
この場合は回折によって生じる出射光の振れは単なる反
射光の場合の振れに比べ約２．７４倍であり、これに相
当した分解能の向上が得られる。The angle θ between the incident direction projected perpendicularly to the XZ plane and the normal direction is 9.20 degrees, and the outgoing direction and the normal line of the (1,0) th order diffracted light projected perpendicularly to the XZ plane. The angle φ with the direction is 77.3 degrees. Further, the angle θ between the incident direction and the normal direction projected perpendicularly to the YZ plane is 9.20 degrees, and the outgoing direction and the normal direction of the (0, 1) -th order diffracted light projected perpendicularly to the YZ plane. The angle φ with is 77.3 degrees.
In this case, the shake of the emitted light caused by diffraction is about 2.74 times the shake of the simply reflected light, and a corresponding improvement in resolution can be obtained.
【００３５】また、原子間力、摩擦力の変わりにマクス
ウェル応力にすれば走査型マクスウェル応力顕微鏡にな
る。他の構成は実施例１と同様である。If the Maxwell stress is used instead of the atomic force and the frictional force, a scanning Maxwell stress microscope is obtained. Other configurations are similar to those of the first embodiment.
【００３６】[0036]
【発明の効果】本発明によれば、分解能を高くすること
ができるカンチレバーと、高い分解能を有する走査型フ
ォース顕微鏡を得ることができる。According to the present invention, it is possible to obtain a cantilever having a high resolution and a scanning force microscope having a high resolution.
【図１】本発明にもとづくカンチレバーの構成図FIG. 1 is a block diagram of a cantilever according to the present invention.
【図２】本発明の第１の実施例による走査型原子間力顕
微鏡の構成図FIG. 2 is a configuration diagram of a scanning atomic force microscope according to a first embodiment of the present invention.
【図３】本発明の第１の実施例による走査型摩擦力顕微
鏡の構成図FIG. 3 is a block diagram of a scanning frictional force microscope according to the first embodiment of the present invention.
【図４】本発明の第１の実施例による走査型原子間力・
摩擦力顕微鏡の構成図FIG. 4 is a scanning atomic force according to the first embodiment of the present invention.
Friction force microscope configuration diagram
【図５】従来技術の走査型フォース顕微鏡の構成図FIG. 5 is a configuration diagram of a conventional scanning force microscope.
１１、２１、３１、４１・・・カンチレバー １２、２２、３２、４２・・・回折格子 １３・・・レーザー光源 ２３、３３、４３、４４・・・二分割光検出器 ２４・・・試料 ２５・・・ＸＹＺ走査装置 ２６・・・走査制御装置 ２７、４５、４６・・・作動増幅器 ２８・・・信号処理装置 11, 21, 31, 41 ... Cantilever 12, 22, 32, 42 ... Diffraction grating 13 ... Laser light source 23, 33, 43, 44 ... Two-part photodetector 24 ... Sample 25 ... XYZ scanning device 26 ... Scanning control device 27, 45, 46 ... Operational amplifier 28 ... Signal processing device
Claims (2)
したことを特徴とするカンチレバー。1. A cantilever characterized in that a diffraction grating is formed on a surface on which laser light is incident.
チレバーと、 試料表面に対する前記カンチレバーの位置を変える走査
手段と、 前記回折格子面からの前記レーザー光の１次以上の回折
光の変化を検出する検出手段とを有し、 前記レーザー光の前記回折格子への入射方向と前記回折
格子面の法線方向とのなす角θと前記レーザー光の前記
回折格子面からの１次以上の回折光の出射方向と前記回
折格子面の法線方向とのなす角φがｃｏｓθ／ｃｏｓφ
＞１を満たすようにしたことを特徴とする走査型フォー
ス顕微鏡。2. A light source for emitting laser light, a cantilever having a diffraction grating formed on a surface on which the laser light is incident, a scanning means for changing the position of the cantilever with respect to a sample surface, and the laser from the diffraction grating surface. A detection means for detecting a change in the diffracted light of the first or higher order of the light, and an angle θ between the incident direction of the laser light to the diffraction grating and the normal direction of the diffraction grating surface and the laser light The angle φ formed by the outgoing direction of the diffracted light of the first or higher order from the diffraction grating surface and the normal direction of the diffraction grating surface is cos θ / cos φ
A scanning force microscope characterized by satisfying> 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5072033A JPH06289036A (en) | 1993-03-30 | 1993-03-30 | Cantilever and scanning force microscope |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5072033A JPH06289036A (en) | 1993-03-30 | 1993-03-30 | Cantilever and scanning force microscope |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06289036A true JPH06289036A (en) | 1994-10-18 |
Family
ID=13477696
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5072033A Pending JPH06289036A (en) | 1993-03-30 | 1993-03-30 | Cantilever and scanning force microscope |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06289036A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6279389B1 (en) * | 1998-11-05 | 2001-08-28 | Nanodevices, Inc. | AFM with referenced or differential height measurement |
| CN1333271C (en) * | 2006-03-10 | 2007-08-22 | 清华大学 | Method for making high dencity grating utilizing laser scanning cofocal microscope |
| JP2020512563A (en) * | 2017-03-31 | 2020-04-23 | カール・ツァイス・エスエムティー・ゲーエムベーハー | Apparatus and method for scanning probe microscope |
-
1993
- 1993-03-30 JP JP5072033A patent/JPH06289036A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6279389B1 (en) * | 1998-11-05 | 2001-08-28 | Nanodevices, Inc. | AFM with referenced or differential height measurement |
| CN1333271C (en) * | 2006-03-10 | 2007-08-22 | 清华大学 | Method for making high dencity grating utilizing laser scanning cofocal microscope |
| JP2020512563A (en) * | 2017-03-31 | 2020-04-23 | カール・ツァイス・エスエムティー・ゲーエムベーハー | Apparatus and method for scanning probe microscope |
| US11237185B2 (en) | 2017-03-31 | 2022-02-01 | Carl Zeiss Smt Gmbh | Apparatus and method for a scanning probe microscope |
| JP2022070996A (en) * | 2017-03-31 | 2022-05-13 | カール・ツァイス・エスエムティー・ゲーエムベーハー | Apparatus and method for scanning probe microscope |
| US11796563B2 (en) | 2017-03-31 | 2023-10-24 | Carl Zeiss Smt Gmbh | Apparatus and method for a scanning probe microscope |
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