JP2004132823A

JP2004132823A - Sampling scanning probe microscope and scanning method

Info

Publication number: JP2004132823A
Application number: JP2002297363A
Authority: JP
Inventors: Shu Kitajima; 北島　周; Akira Inoue; 井上　明; Masatoshi Yasutake; 安武　正敏; Kazutoshi Watanabe; 渡辺　和俊; Shigeru Wakiyama; 脇山　茂
Original assignee: Seiko Instruments Inc
Current assignee: Seiko Instruments Inc
Priority date: 2002-10-10
Filing date: 2002-10-10
Publication date: 2004-04-30
Anticipated expiration: 2022-10-10
Also published as: JP4021298B2

Abstract

<P>PROBLEM TO BE SOLVED: To implement a sampling scanning probe microscope capable of preventing a probe and a sample from being damaged due to the collision between the probe and the sample. <P>SOLUTION: The sampling scanning probe microscope is provided with both an amplitude attenuation detecting part 41 and a control part 24. The amplitude attenuation detecting part 41 detects the degree of attenuation of an amplitude by vibrations in the probe 5 at a point in time when the probe 5 comes close to or into contact with the surface of the sample 2. The control part 24 controls movements in a z-direction in such a way as to halt the probe 5 from coming close to the surface of the sample 2 when the detected degree of attenuation reaches a previously set threshold value and to separate the probe 5 from the surface of the sample 2 by a prescribed distance at which the probe 5 does not come into contact with the surface of the sample 2 during the next scanning period in an x- or y-direction after the halting. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、サンプリング走査プローブ顕微鏡に係り、特に探針を試料表面上で、上下に往復動させることにより、試料表面の形状情報、物理情報等を得ることのできるサンプリング走査プローブ顕微鏡および走査方法に関する。
【０００２】
【従来の技術】
従来のサンプリング走査型のプローブ顕微鏡（サンプリング走査プローブ顕微鏡）は、試料面に平行なｘ、ｙ方向の走査と、該試料面に垂直なｚ方向の移動とを該試料面に対して相対的に行える探針を備え、試料を走査する際に該探針が試料の表面を軽く叩くように、該探針を、これに共振するあるいは強制振動する振動用周波数で振動させる。さらに、ｘ方向の走査時間とｘ方向の画素数とで決まるｚ方向移動用周波数で探針をｚ方向に移動させる。これにより、探針が試料表面を叩く回数を減らして、試料の損傷を低減させるとともに、探針の長寿命化を図っている（例えば、特許文献１参照）。
【０００３】
【特許文献１】
特許第３２８６５６５号公報
【０００４】
【発明が解決しようとする課題】
しかし、上述した従来のサンプリング走査プローブ顕微鏡では、ｚ方向移動用周波数で探針を試料から引き離すが、試料形状が急峻な部分では探針と試料が衝突して大きな力が加わり、探針や試料を損傷する虞がある。
【０００５】
本発明は、このような事情を考慮してなされたもので、その目的は、探針と試料が衝突することによって探針や試料が損傷することを防止することができるサンプリング走査プローブ顕微鏡および走査方法を提供することにある。
【０００６】
【課題を解決するための手段】
上記の課題を解決するために、本発明のサンプリング走査プローブ顕微鏡は、試料面に平行なｘ、ｙ方向の走査と、該試料面に垂直なｚ方向の移動とを該試料面に対して相対的に行える探針を備えたサンプリング走査プローブ顕微鏡において、前記探針を、これに共振するあるいは強制振動する振動用周波数で振動させる手段と、前記探針が試料の表面に近接または接触した時点における観測データを採取する手段と、前記探針が前記試料表面に近接または接触した時点における該探針の振動振幅の減衰度合いを検出する手段と、前記ｚ方向の移動を制御する制御手段とを具備し、前記制御手段は、前記検出された減衰度合いが予め設定されている閾値に達すると、前記探針と前記試料表面の接近を停止させ、この接近停止後に、前記ｘまたはｙ方向の次回の走査期間中に前記探針と前記試料表面が接触することのない所定距離まで前記探針を前記試料表面から離すことを特徴としている。
【０００７】
また、本発明のサンプリング走査プローブ顕微鏡において、前記制御手段は、前記接近停止後、該探針の振動振幅の減衰度合いが前記閾値で一定となるように、前記ｚ方向の移動を制御することを特徴とする。
【０００８】
上記の課題を解決するために、本発明のサンプリング走査プローブ顕微鏡は、試料面に平行なｘ、ｙ方向の走査と、該試料面に垂直なｚ方向の移動とを該試料面に対して相対的に行える探針を備えたサンプリング走査プローブ顕微鏡において、前記探針を、これに共振するあるいは強制振動する振動用周波数で振動させる手段と、前記探針が試料の表面に近接または接触した時点における観測データを採取する手段と、前記探針が前記試料表面に近接または接触した時点における該探針の振動の位相の変化度合いを検出する手段と、前記ｚ方向の移動を制御する制御手段とを具備し、前記制御手段は、前記検出された変化度合いが予め設定されている閾値に達すると、前記探針と前記試料表面の接近を停止させ、この接近停止後に、前記ｘまたはｙ方向の次回の走査期間中に前記探針と前記試料表面が接触することのない所定距離まで前記探針を前記試料表面から離すことを特徴としている。
【０００９】
また、本発明のサンプリング走査プローブ顕微鏡において、前記制御手段は、前記接近停止後、該探針の振動の位相の変化度合いが前記閾値で一定となるように、前記ｚ方向の移動を制御することを特徴とする。
【００１０】
上記の課題を解決するために、本発明のサンプリング走査プローブ顕微鏡は、試料面に平行なｘ、ｙ方向の走査と、該試料面に垂直なｚ方向の移動とを該試料面に対して相対的に行える探針を備えたサンプリング走査プローブ顕微鏡において、前記探針を、これに共振するあるいは強制振動する振動用周波数で振動させる手段と、前記探針が試料の表面に近接または接触した時点における観測データを採取する手段と、前記探針が前記試料表面に近接または接触した時点における該探針の振動の周波数の変化度合いを検出する手段と、前記ｚ方向の移動を制御する制御手段とを具備し、前記制御手段は、前記検出された変化度合いが予め設定されている閾値に達すると、前記探針と前記試料表面の接近を停止させ、この接近停止後に、前記ｘまたはｙ方向の次回の走査期間中に前記探針と前記試料表面が接触することのない所定距離まで前記探針を前記試料表面から離すことを特徴としている。
【００１１】
また、本発明のサンプリング走査プローブ顕微鏡において、前記制御手段は、前記接近停止後、該探針の振動の周波数の変化度合いが前記閾値で一定となるように、前記ｚ方向の移動を制御することを特徴とする。
【００１２】
また、本発明のサンプリング走査プローブ顕微鏡において、前記探針と前記試料表面の接近を停止させた時点の該探針のｚ方向の位置を検出し、この位置データをｚ方向の観測データとすることを特徴とする。
【００１３】
また、本発明のサンプリング走査プローブ顕微鏡において、前記探針と前記試料表面の接近を停止させた時点の該探針のｚ方向の位置を検出し、該停止させた時点における該探針の振動振幅の減衰度合いと前記閾値との差分に基づいて前記検出した位置を補正する手段を備え、前記補正後の位置データをｚ方向の観測データとすることを特徴とする。
【００１４】
また、本発明のサンプリング走査プローブ顕微鏡において、前記ｚ方向の観測データと、前記ｘおよびｙ方向の走査に使用された駆動データとを組み合わせて三次元のイメージデータを生成し、該イメージデータにより画像表示することを特徴とする。
【００１５】
また、本発明のサンプリング走査プローブ顕微鏡において、前記探針と前記試料表面を接近させる動作および離す動作が直線移動であることを特徴とする。
【００１６】
また、本発明のサンプリング走査プローブ顕微鏡において、前記探針と前記試料表面を接近させるときの前記直線移動の速度が、前記離すときの該速度と異なることを特徴とする。
【００１７】
また、本発明のサンプリング走査プローブ顕微鏡において、前記離すときの速度が、前記接近するときの速度よりも大きいことを特徴とする。
【００１８】
また、本発明のサンプリング走査プローブ顕微鏡において、前記直線移動の速度が、前記探針と前記試料表面を接近させる動作および離す動作の少なくとも一方において減速制御されることを特徴とする。
【００１９】
また、本発明のサンプリング走査プローブ顕微鏡において、前記直線移動の速度が毎秒１マイクロメートル以上であることを特徴とする。
また、本発明のサンプリング走査プローブ顕微鏡において、前記直線移動の速度が毎秒２マイクロメートル以上であることを特徴とする。
また、本発明のサンプリング走査プローブ顕微鏡において、前記直線移動の速度が毎秒４マイクロメートル以上であることを特徴とする。
また、本発明のサンプリング走査プローブ顕微鏡において、前記直線移動の速度が毎秒６マイクロメートル以上であることを特徴とする。
【００２０】
上記の課題を解決するために、本発明の走査方法は、試料面に平行なｘ、ｙ方向の走査と、該試料面に垂直なｚ方向の移動とを該試料面に対して相対的に行える探針を備え、該探針を、これに共振するあるいは強制振動する振動用周波数で振動させ、該探針が試料の表面に近接または接触した時点における観測データを採取するサンプリング走査プローブ顕微鏡における走査方法であって、前記探針が前記試料表面に近接または接触した時点における該探針の振動振幅の減衰度合いを検出する過程と、前記検出された減衰度合いが予め設定されている閾値に達すると、前記探針と前記試料表面の接近を停止させる過程と、この接近停止後に、前記ｘまたはｙ方向の次回の走査期間中に前記探針と前記試料表面が接触することのない所定距離まで前記探針を前記試料表面から離す過程と、を含むことを特徴としている。
【００２１】
上記の課題を解決するために、本発明の走査方法は、試料面に平行なｘ、ｙ方向の走査と、該試料面に垂直なｚ方向の移動とを該試料面に対して相対的に行える探針を備え、該探針を、これに共振するあるいは強制振動する振動用周波数で振動させ、該探針が試料の表面に近接または接触した時点における観測データを採取するサンプリング走査プローブ顕微鏡における走査方法であって、前記探針が前記試料表面に近接または接触した時点における該探針の振動の位相の変化度合いを検出する過程と、前記検出された変化度合いが予め設定されている閾値に達すると、前記探針と前記試料表面の接近を停止させる過程と、この接近停止後に、前記ｘまたはｙ方向の次回の走査期間中に前記探針と前記試料表面が接触することのない所定距離まで前記探針を前記試料表面から離す過程と、を含むことを特徴としている。
【００２２】
上記の課題を解決するために、本発明の走査方法は、試料面に平行なｘ、ｙ方向の走査と、該試料面に垂直なｚ方向の移動とを該試料面に対して相対的に行える探針を備え、該探針を、これに共振するあるいは強制振動する振動用周波数で振動させ、該探針が試料の表面に近接または接触した時点における観測データを採取するサンプリング走査プローブ顕微鏡における走査方法であって、前記探針が前記試料表面に近接または接触した時点における該探針の振動の周波数の変化度合いを検出する過程と、前記検出された変化度合いが予め設定されている閾値に達すると、前記探針と前記試料表面の接近を停止させる過程と、この接近停止後に、前記ｘまたはｙ方向の次回の走査期間中に前記探針と前記試料表面が接触することのない所定距離まで前記探針を前記試料表面から離す過程と、を含むことを特徴としている。
【００２３】
【発明の実施の形態】
以下、図面を参照し、本発明の実施形態について説明する。
図１は、本発明の第１の実施形態によるサンプリング走査プローブ顕微鏡の構成を示すブロック図である。この図１のサンプリング走査プローブ顕微鏡において、観察される試料２は試料台４の上面に載置される。該試料２の上方には、該試料２と対向する探針５を一端に有するカンチレバー６が設けられ、該カンチレバー６の他の一端にはバイモルフ８が固定されている。バイモルフ８は、加振電源１８によりカンチレバー６を共振または強制振動させる。この振動用周波数は、例えば１００ｋＨｚである。これにより、探針５が振動用周波数で振動する。
【００２４】
カンチレバー６のバイモルフ８側の一端は３次元アクチュエータ１４に固定されている。３次元アクチュエータ１４は、試料２の試料面に平行なｘおよびｙ方向に走査する動作と、該試料面に垂直なｚ方向に移動する動作を行う。これにより、探針５は、試料２の試料面に対して該ｘ、ｙ方向の走査と、該ｚ方向の移動が可能となる。
【００２５】
３次元アクチュエータ１４には、探針５と対向する位置にカンチレバー変位検出器１０が設けられている。カンチレバー６の探針５部分の変位量は、レーザ発生器１２から出力されたレーザ光９の入射位置をカンチレバー変位検出器１０で測定することにより検出される。この検出された変位量は振幅減衰検出部１６へ出力される。振幅減衰検出部１６は、該変位量に基づいて探針５の振動振幅を求め、さらに該振動振幅の減衰度合いを求める。振動振幅の減衰度合いとしては、実際の減衰量を使用してもよく、あるいは減衰率を使用してもよい。
【００２６】
ＸＹ駆動部２０は、３次元アクチュエータ１４を駆動して試料２の試料面に平行なｘまたはｙ方向の走査を行う。Ｚ駆動部２２は、３次元アクチュエータ１４を駆動して試料２の試料面に垂直なｚ方向の移動を行う。制御部２４は、振幅減衰検出部１６によって検出された探針５の振動振幅の減衰度合いに基づいて、Ｚ駆動部２２に対して該ｚ方向の移動の制御を行う。
【００２７】
図２、図３を参照して、上記制御部２４の動作および本実施形態の走査方法を説明する。図２は本実施形態の走査方法を説明するための概念図である。図３は、探針５の振動振幅の減衰度合いを説明するための振動波形図である。図２には、探針５の移動軌跡と、試料表面２ａ上の測定点２０１を示している。探針５の移動軌跡は、ｘ、ｙ方向の軌跡１０１＿ｘｙとｚ方向の軌跡１０１＿ｚとからなる。
【００２８】
初めに、探針５は、バイモルフ８によって振動用周波数で振動している。この状態で、図２に示すように、ＸＹ駆動部２０は、探針５をｘ、ｙ方向に走査させて、ある測定点２０１の上方に到達した時に該走査を停止する。このｘ、ｙ方向走査時には探針５は、試料表面２ａと衝突することのないように、試料表面２ａからｚ方向に所定距離だけ離れている。該所定距離だけ試料表面２ａから離れたｚ方向の位置Ｚａは予め設定されている。ｘ、ｙ方向走査時の探針５は、図３（ａ）に示す振動波形Ｗ１のように、振動振幅Ａで振動している。
【００２９】
次いで、Ｚ駆動部２２は、測定点２０１の上方にある探針５をｚ方向に移動させて試料表面２ａに接近させる。これにより探針５が試料表面２ａに近接もしくは接触すると、該探針５の振動振幅は、図３（ｂ）に示す振動波形Ｗ２のように、振動振幅Ａ’に減衰する。振幅減衰検出部１６は、この振動振幅の減衰度合い「Ａ−Ａ’」を算出して予め設定されている閾値Ｔｈ１と比較し、減衰度合い「Ａ−Ａ’」が該閾値Ｔｈ１に達すると、その旨を制御部２４へ通知する。制御部２４は、この通知を受けると、Ｚ駆動部２２へ移動停止を指示する。これにより、探針５と試料２に損傷を与えるほど大きな力が加わる前に探針５が停止するので、該探針５や試料２が損傷することはない。上記探針５の移動を停止指示した時点で、当該測定点２０１のｚ方向の観測データが採取される。
【００３０】
次いで、制御部２４は、上記位置Ｚａまで探針５をｚ方向に移動させる。探針５が位置Ｚａに到達すると、ＸＹ駆動部２０は、探針５を次の測定点２０１の上方までｘ、ｙ方向に走査させる。
上記ｘ、ｙ方向の走査とｚ方向の移動を繰り返し実行することにより、試料表面２ａの走査が行われ、各測定点２０１の観測データが採取される。
【００３１】
次に、上記走査により観測データを採取する構成と動作を説明する。
図１において、補正量算出部２６は、ｚ方向の探針５の位置データを補正するための補正量を求める。Ｚデータ演算部２８は、Ｚ駆動部２２の駆動データを元に、探針５が停止した時点の該探針５のｚ方向の位置を検出し、この位置データに補正量算出部２６で求めた補正量を合算して、ｚ方向の観測データとする。
【００３２】
イメージデータ生成部３０は、Ｚデータ演算部２８により求められたｚ方向の観測データと、ＸＹ駆動部２０によりｘおよびｙ方向の走査に使用された駆動データとを組み合わせて、三次元のイメージデータを生成する。このイメージデータは、表示部３２により三次元の画像として再生および表示される。
【００３３】
図４を参照して、上記補正量算出部２６およびＺデータ演算部２８の補正処理について説明する。図４には、探針５のｚ方向の位置に対応する変位の波形を示している。
図４に示すように、探針５が試料表面２ａ近傍の位置Ｚ０まで到達すると、探針５に力が作用し、振動振幅が減衰し始める。そして、位置Ｚ１にて、振動振幅の減衰度合いが予め設定されている閾値Ｔｈ１に達したとする。この時点で制御部２４はＺ駆動部２２へｚ方向の移動停止を指示し、これにより探針５の試料表面２ａへの接近動作は停止する。しかし、該移動停止の指示時点から探針５が停止するまでの応答時間の分だけ、探針５の接近動作は継続するので、実際には探針５は位置Ｚ２で停止する。この位置Ｚ２の位置データをそのままｚ方向の観測データとすると、位置Ｚ１とＺ２の差ΔＺが「接近量のブレ」となり、これがｚ方向の観測データの誤差要因となる。本実施形態では、位置Ｚ２の位置データに対して上記差ΔＺ分を補正することによって、正確なｚ方向の観測データを得るようにする。
【００３４】
図４において、位置Ｚ１の振幅Ａ１と位置Ｚ２の振幅Ａ２との差ΔＡは、ｚ方向の長さであるので、上記差ΔＺに等しい。従って、差ΔＡが得られれば位置Ｚ２の位置データの上記補正が可能である。そこで、振幅減衰検出部１６は、振動振幅の減衰度合いが閾値Ｔｈ１に達したときの振動振幅、すなわち位置Ｚ１の振幅Ａ１を補正量算出部２６へ出力する。さらに、探針５の接近動作が停止したときの振動振幅、すなわち位置Ｚ２の振幅Ａ２を補正量算出部２６へ出力する。これにより、補正量算出部２６は、位置Ｚ１の振幅Ａ１と位置Ｚ２の振幅Ａ２を得ることができ、該振幅Ａ１とＡ２の差ΔＡを求めて補正量ΔＺとし、この補正量ΔＺをＺデータ演算部２８へ出力する。Ｚデータ演算部２８は、該補正量ΔＺとＺ駆動部２２から得た位置Ｚ２の位置データとを合算し、この合算値をｚ方向の観測データとする。これにより、補正された正確なｚ方向の観測データが採取可能となる。
【００３５】
なお、制御部２４は、探針５の接近停止後、該探針５の振動振幅の減衰度合いが閾値Ｔｈ１で一定となるように、ｚ方向の移動を制御するようにしてもよい。このようにすれば、探針５は、振動振幅の減衰度合いが閾値Ｔｈ１に達した位置Ｚ１を略維持するので、上記補正なしでも正確なｚ方向の観測データを採取することができる。また、ｚ方向の観測データの精度を更に向上するために、上記補正と組み合わせてもよい。
【００３６】
次に、図５を参照して第２の実施形態を説明する。図５は、本発明の第２の実施形態によるサンプリング走査プローブ顕微鏡の構成を示すブロック図である。この図５において図１の各部に対応する部分には同一の符号を付け、その説明を省略する。
第２の実施形態によるサンプリング走査プローブ顕微鏡においては、探針５の振動の位相の変化度合いに基づいて該探針５のｚ方向の移動を制御する。図５に示すように、第２の実施形態によるサンプリング走査プローブ顕微鏡は位相変化検出部４１を備える。この位相変化検出部４１は、探針５の振動の位相の変化度合いを検出する。位相の変化度合いとしては、実際の変化量を使用してもよく、あるいは変化率を使用してもよい。位相変化検出部４１は、該位相の変化度合いと予め設定されている閾値Ｔｈ２とを比較し、該変化度合いが該閾値Ｔｈ２に達すると、その旨を制御部２４へ通知する。これにより制御部２４は、上記第１の実施形態と同様に、Ｚ駆動部２２に対してｚ方向の移動の制御を行う。
【００３７】
この第２の実施形態では、イメージデータ生成部３０は、探針５と試料表面２ａの接近停止時点のＺデータ駆動部２２の駆動データを元に、該探針５のｚ方向の位置を検出し、この位置データをｚ方向の観測データとする。
【００３８】
なお、第２の実施形態において制御部２４が、探針５の接近停止後、該探針５の振動の位相の変化度合いが上記閾値Ｔｈ２で一定となるように、ｚ方向の移動を制御するのが好ましい。このようにすれば、探針５は、振動の位相の変化度合いが閾値Ｔｈ２に達した位置を略維持するので、正確なｚ方向の観測データを採取することができる。
【００３９】
次に、図６を参照して第３の実施形態を説明する。図６は、本発明の第３の実施形態によるサンプリング走査プローブ顕微鏡の構成を示すブロック図である。この図６において図１の各部に対応する部分には同一の符号を付け、その説明を省略する。
第３の実施形態によるサンプリング走査プローブ顕微鏡においては、探針５の振動の周波数の変化度合いに基づいて該探針５のｚ方向の移動を制御する。図６に示すように、第３の実施形態によるサンプリング走査プローブ顕微鏡は、位相調整器５１と増幅器５２と周波数／電圧変換器（Ｆ−Ｖ変換器）５３を備える。位相調整器５１は、カンチレバー変位検出器１０の出力を、カンチレバー６が共振周波数で振動するように調整して増幅器５２に出力する。増幅器５２はこの入力信号を所定の増幅度で増幅して、バイモルフ８とＦ−Ｖ変換器５３へ出力する。バイモルフ８はこの入力信号によりカンチレバー６および探針５を振動させる。
【００４０】
Ｆ−Ｖ変換器５３は、増幅器５２から入力された信号の周波数を対応する電圧信号に変換して制御部２４へ出力する。制御部２４は、この入力された電圧信号に基づいて、探針５の振動の周波数の変化度合いを検出する。周波数の変化度合いとしては、実際の変化量を使用してもよく、あるいは変化率を使用してもよい。制御部２４は、該周波数の変化度合いと予め設定されている閾値Ｔｈ３とを比較し、該変化度合いが該閾値Ｔｈ３に達すると、上記第１の実施形態と同様に、Ｚ駆動部２２に対してｚ方向の移動の制御を行う。
【００４１】
この第３の実施形態では、上記第２の実施形態と同様に、イメージデータ生成部３０は、探針５と試料表面２ａの接近停止時点のＺデータ駆動部２２の駆動データを元に、該探針５のｚ方向の位置を検出し、この位置データをｚ方向の観測データとする。
【００４２】
なお、第３の実施形態において制御部２４が、探針５の接近停止後、該探針５の振動の周波数の変化度合いが上記閾値Ｔｈ３で一定となるように、ｚ方向の移動を制御するのが好ましい。このようにすれば、探針５は、振動の周波数の変化度合いが閾値Ｔｈ３に達した位置を略維持するので、正確なｚ方向の観測データを採取することができる。
【００４３】
なお、上述した第１〜第３の実施形態においては、３次元アクチュエータ１４により探針５のｘ、ｙ方向の走査とｚ方向の移動を行ったが、これらｘ、ｙ方向の走査とｚ方向の移動は試料２の試料面に対して相対的に行われればよい。例えば、試料台４を動かすことによって該ｘ、ｙ方向の走査とｚ方向の移動を行うようにしてもよい。
【００４４】
また、図２に示すように、探針５と試料表面２ａを接近させる動作および離す動作を直線移動としたが、ｘ、ｙ方向に移動中に該接近または離す動作を行って探針５がｚ方向に曲線移動するようにしてもよい。但し、探針５の振動の振幅、位相、周波数の変化を精度よく検出するために、直線移動とするのが好ましい。
【００４５】
また、探針５と試料表面２ａを接近させるときの直線移動の速度が、探針５を試料表面２ａから離すときの直線移動の速度と異なるようにしてもよい。この場合、離すときの速度を、接近するときの速度よりも大きくするのが好ましい。この理由は、接近するときには探針５の振動の振幅、位相、周波数の変化を精度よく検出可能な速度としても、離すときに速度を上げることで測定時間を短縮することが可能なためである。
【００４６】
なお、探針５のｚ方向の直線移動の速度について、探針５と試料表面２ａを接近させる動作および離す動作の少なくとも一方において減速制御するようにしてもよい。好ましくは接近するときに減速制御するのが、探針５の振動の振幅、位相、周波数の変化を精度よく検出する上でよい。
【００４７】
なお、探針５のｚ方向の直線移動の速度については、毎秒１マイクロメートル以上とするのが測定時間を短縮する観点から好ましい。さらには、毎秒２マイクロメートル以上とするのが好ましく、毎秒４マイクロメートル以上とすればより好ましい。さらに、毎秒６マイクロメートル以上とすれば測定時間を大幅に短縮することが可能となる。
【００４８】
なお、上述した第１〜第３の実施形態においては、光検知式のカンチレバーによって探針部分の変位量を検出するようにしたが、光検知式以外のカンチレバーを用いてもよい。例えば自己の変位量を検知する自己検知レバーを用いることも可能である。
【００４９】
以上、本発明の実施形態を図面を参照して詳述してきたが、具体的な構成はこの実施形態に限られるものではなく、本発明の要旨を逸脱しない範囲の設計変更等も含まれる。
【００５０】
【発明の効果】
以上説明したように、本発明によれば、探針と試料が衝突することによって探針や試料が損傷することを防止することができる。また、高速に探針を試料に近接または接触させることができるので、測定時間を短縮することが可能となる。これにより、凹凸が激しい試料の測定や大領域の測定が容易に実施可能となる。
【００５１】
また、探針と試料表面との接近停止時における応答時間分の「接近量のブレ」を補正して観測データを採取するので、より高精度の測定を行うことができる。
【図面の簡単な説明】
【図１】本発明の第１の実施形態によるサンプリング走査プローブ顕微鏡の構成を示すブロック図である。
【図２】本発明の走査方法を説明するための概念図である。
【図３】探針５の振動振幅の減衰度合いを説明するための振動波形図である。
【図４】図１に示す補正量算出部２６およびＺデータ演算部２８の補正処理を説明するための振動波形図である。
【図５】本発明の第２の実施形態によるサンプリング走査プローブ顕微鏡の構成を示すブロック図である。
【図６】本発明の第３の実施形態によるサンプリング走査プローブ顕微鏡の構成を示すブロック図である。
【符号の説明】
２…試料、２ａ…試料表面、４…試料台、５…探針、６…カンチレバー、８…バイモルフ、９…レーザ光、１０…カンチレバー変位検出器、１２…レーザ発生器、１４…３次元アクチュエータ、１６…振幅減衰検出部、１８…加振電源、２０…ＸＹ駆動部、２２…Ｚ駆動部、２４…制御部、２６…補正量算出部、２８…Ｚデータ演算部、３０…イメージデータ生成部、３２…表示部、４１…位相変化検出部、５１…位相調整器、５２…増幅器、５３…周波数／電圧変換器（Ｆ−Ｖ変換器）[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a sampling scanning probe microscope, and more particularly, to a sampling scanning probe microscope and a scanning method capable of obtaining shape information, physical information, and the like of a sample surface by reciprocating a probe up and down on the sample surface. .
[0002]
[Prior art]
A conventional sampling scanning probe microscope (sampling scanning probe microscope) performs scanning in x and y directions parallel to a sample surface and movement in a z direction perpendicular to the sample surface relative to the sample surface. The probe is made vibrating at a vibration frequency that resonates with or forcibly vibrates the probe so that the probe slightly taps the surface of the sample when scanning the sample. You. Further, the probe is moved in the z direction at a z direction movement frequency determined by the scanning time in the x direction and the number of pixels in the x direction. This reduces the number of times the probe hits the sample surface, thereby reducing damage to the sample and extending the life of the probe (for example, see Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent No. 3286565
[0004]
[Problems to be solved by the invention]
However, in the conventional sampling scanning probe microscope described above, the probe is separated from the sample at the frequency for moving in the z direction, but in a portion where the sample shape is steep, the probe and the sample collide and a large force is applied, and the probe and the sample are moved. May be damaged.
[0005]
The present invention has been made in view of such circumstances, and a purpose thereof is to provide a sampling scanning probe microscope and a scanning microscope capable of preventing a probe and a sample from being damaged by collision between the probe and the sample. It is to provide a method.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, a sampling scanning probe microscope according to the present invention provides scanning in x and y directions parallel to a sample surface and movement in a z direction perpendicular to the sample surface relative to the sample surface. In a sampling scanning probe microscope equipped with a probe that can be performed, the probe vibrates at a vibration frequency that resonates or forcibly vibrates with the probe, and the probe at the time when the probe approaches or comes into contact with the surface of the sample. Means for collecting observation data, means for detecting the degree of attenuation of the vibration amplitude of the probe when the probe approaches or comes into contact with the sample surface, and control means for controlling movement in the z direction. When the detected degree of attenuation reaches a predetermined threshold value, the control means stops the approach between the probe and the sample surface. Is characterized by a predetermined distance not to the probe and the surface of the sample during the next scanning period in the y direction are in contact releases the probe from the sample surface.
[0007]
Further, in the sampling scanning probe microscope of the present invention, the control means controls the movement in the z direction such that the degree of attenuation of the vibration amplitude of the probe becomes constant at the threshold after the approach stop. Features.
[0008]
In order to solve the above problems, a sampling scanning probe microscope according to the present invention provides scanning in x and y directions parallel to a sample surface and movement in a z direction perpendicular to the sample surface relative to the sample surface. In a sampling scanning probe microscope equipped with a probe that can be performed, the probe vibrates at a vibration frequency that resonates or forcibly vibrates with the probe, and the probe at the time when the probe approaches or comes into contact with the surface of the sample. Means for collecting observation data, means for detecting the degree of change in the phase of vibration of the probe when the probe approaches or comes into contact with the sample surface, and control means for controlling movement in the z direction. The control means stops the approach between the probe and the sample surface when the detected degree of change reaches a preset threshold value, and after stopping the approach, the x or Is characterized by separating the said probe to a predetermined distance not to contact the probe and the surface of the sample during the next scanning period in the y direction from the sample surface.
[0009]
Further, in the sampling scanning probe microscope according to the present invention, the control unit controls the movement in the z direction such that the degree of change in the phase of vibration of the probe after the approach stop is constant at the threshold. It is characterized by.
[0010]
In order to solve the above problems, a sampling scanning probe microscope according to the present invention provides scanning in x and y directions parallel to a sample surface and movement in a z direction perpendicular to the sample surface relative to the sample surface. In a sampling scanning probe microscope equipped with a probe that can be performed, the probe vibrates at a vibration frequency that resonates or forcibly vibrates with the probe, and the probe at the time when the probe approaches or comes into contact with the surface of the sample. Means for collecting observation data, means for detecting the degree of change in the frequency of vibration of the probe when the probe approaches or comes into contact with the sample surface, and control means for controlling movement in the z direction. When the detected degree of change reaches a preset threshold value, the control means stops the approach between the probe and the sample surface, and after the approach stop, the x Others are characterized by separating the said probe to a predetermined distance not to contact the probe and the surface of the sample during the next scanning period in the y direction from the sample surface.
[0011]
Further, in the sampling scanning probe microscope according to the present invention, the control means controls the movement in the z direction such that the degree of change in the frequency of vibration of the probe after the approach stop is constant at the threshold. It is characterized by.
[0012]
In the sampling scanning probe microscope of the present invention, the position of the probe in the z direction at the time when the approach between the probe and the sample surface is stopped is detected, and the position data is used as observation data in the z direction. It is characterized by.
[0013]
In the sampling scanning probe microscope of the present invention, the position of the probe in the z direction at the time when the approach between the probe and the sample surface is stopped is detected, and the vibration amplitude of the probe at the time of the stop is detected. Means for correcting the detected position based on a difference between the degree of attenuation and the threshold value, and the corrected position data is used as observation data in the z direction.
[0014]
In the sampling scanning probe microscope of the present invention, the observation data in the z direction and the driving data used in the scanning in the x and y directions are combined to generate three-dimensional image data, and the image data is used to generate an image. It is characterized by displaying.
[0015]
Further, in the sampling scanning probe microscope according to the present invention, the operation of approaching and separating the probe from the surface of the sample is a linear movement.
[0016]
Further, in the sampling scanning probe microscope of the present invention, the speed of the linear movement when the probe and the sample surface are approached is different from the speed when the probe is separated.
[0017]
Further, in the sampling scanning probe microscope according to the present invention, the speed at the time of separation is higher than the speed at the time of approach.
[0018]
Further, in the sampling scanning probe microscope according to the present invention, the speed of the linear movement is controlled to be decelerated in at least one of an operation of bringing the probe and the sample surface closer to or away from the sample surface.
[0019]
Further, in the sampling scanning probe microscope according to the present invention, the speed of the linear movement is at least 1 micrometer per second.
Further, in the sampling scanning probe microscope according to the present invention, the speed of the linear movement is 2 micrometers or more per second.
In the sampling scanning probe microscope according to the present invention, the speed of the linear movement is 4 micrometers or more per second.
In the sampling scanning probe microscope according to the present invention, the speed of the linear movement is 6 micrometers or more per second.
[0020]
In order to solve the above-mentioned problem, the scanning method of the present invention provides scanning in x and y directions parallel to a sample surface and movement in a z direction perpendicular to the sample surface relative to the sample surface. In a sampling scanning probe microscope, the probe is provided with a probe capable of being vibrated, and the probe is vibrated at a vibration frequency that resonates with or forcibly vibrates to obtain observation data when the probe approaches or touches the surface of the sample. A scanning method, wherein a step of detecting the degree of attenuation of the vibration amplitude of the probe at the time when the probe approaches or contacts the sample surface, and wherein the detected degree of attenuation reaches a predetermined threshold value Then, a step of stopping the approach between the probe and the sample surface, and after stopping the approach, to a predetermined distance where the probe and the sample surface do not come into contact during the next scanning period in the x or y direction. It is characterized in that it comprises the steps of releasing the probe from the sample surface.
[0021]
In order to solve the above-mentioned problem, the scanning method of the present invention provides scanning in x and y directions parallel to a sample surface and movement in a z direction perpendicular to the sample surface relative to the sample surface. In a sampling scanning probe microscope, the probe is provided with a probe capable of being vibrated, and the probe is vibrated at a vibration frequency that resonates with or forcibly vibrates to obtain observation data when the probe approaches or touches the surface of the sample. In the scanning method, a step of detecting a degree of change in the phase of vibration of the probe at the time when the probe approaches or contacts the sample surface, and the detected degree of change corresponds to a predetermined threshold. Upon reaching, a step of stopping the approach between the probe and the sample surface, and after this stop, a predetermined distance such that the probe and the sample surface do not come into contact during the next scanning period in the x or y direction. In it is characterized in that it comprises the steps of releasing the probe from the sample surface.
[0022]
In order to solve the above-mentioned problem, the scanning method of the present invention provides scanning in x and y directions parallel to a sample surface and movement in a z direction perpendicular to the sample surface relative to the sample surface. In a sampling scanning probe microscope, the probe is provided with a probe capable of being vibrated, and the probe is vibrated at a vibration frequency that resonates with or forcibly vibrates to obtain observation data when the probe approaches or touches the surface of the sample. A scanning method, wherein the step of detecting the degree of change in the frequency of vibration of the probe at the time when the probe approaches or comes into contact with the sample surface, and the detected degree of change is a predetermined threshold Upon reaching, stopping the approach between the probe and the sample surface, and after the approach stop, a predetermined distance such that the probe does not come into contact with the sample surface during the next scanning period in the x or y direction. It is characterized in that it comprises the steps of releasing the probe from the sample surface to.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of a sampling scanning probe microscope according to the first embodiment of the present invention. In the sampling scanning probe microscope of FIG. 1, the sample 2 to be observed is placed on the upper surface of the sample stage 4. A cantilever 6 having a probe 5 at one end facing the sample 2 is provided above the sample 2, and a bimorph 8 is fixed to the other end of the cantilever 6. The bimorph 8 causes the cantilever 6 to resonate or forcibly vibrate by the vibration power supply 18. This vibration frequency is, for example, 100 kHz. Thus, the probe 5 vibrates at the vibration frequency.
[0024]
One end of the cantilever 6 on the bimorph 8 side is fixed to the three-dimensional actuator 14. The three-dimensional actuator 14 performs an operation of scanning in the x and y directions parallel to the sample surface of the sample 2 and an operation of moving in the z direction perpendicular to the sample surface. Thus, the probe 5 can scan in the x and y directions with respect to the sample surface of the sample 2 and move in the z direction.
[0025]
The three-dimensional actuator 14 is provided with a cantilever displacement detector 10 at a position facing the probe 5. Cantilever 6 Is detected by measuring the incident position of the laser beam 9 output from the laser generator 12 with the cantilever displacement detector 10. The detected displacement amount is output to the amplitude attenuation detection unit 16. The amplitude attenuation detection unit 16 obtains the vibration amplitude of the probe 5 based on the displacement amount, and further obtains the degree of attenuation of the vibration amplitude. As the degree of attenuation of the vibration amplitude, an actual amount of attenuation may be used, or an attenuation rate may be used.
[0026]
The XY drive unit 20 drives the three-dimensional actuator 14 to perform scanning in the x or y direction parallel to the sample surface of the sample 2. The Z drive unit 22 drives the three-dimensional actuator 14 to move the sample 2 in the z direction perpendicular to the sample surface. The control unit 24 controls the Z drive unit 22 to move in the z direction based on the attenuation degree of the vibration amplitude of the probe 5 detected by the amplitude attenuation detection unit 16.
[0027]
The operation of the control unit 24 and the scanning method of the present embodiment will be described with reference to FIGS. FIG. 2 is a conceptual diagram for explaining the scanning method according to the present embodiment. FIG. 3 is a vibration waveform diagram for explaining the degree of attenuation of the vibration amplitude of the probe 5. FIG. 2 shows a movement locus of the probe 5 and a measurement point 201 on the sample surface 2a. The movement trajectory of the probe 5 includes a trajectory 101_xy in the x and y directions and a trajectory 101_z in the z direction.
[0028]
First, the probe 5 is vibrating at the vibration frequency by the bimorph 8. In this state, as shown in FIG. 2, the XY drive section 20 causes the probe 5 to scan in the x and y directions, and stops the scanning when the probe 5 reaches a position above a certain measurement point 201. During scanning in the x and y directions, the probe 5 is separated from the sample surface 2a by a predetermined distance in the z direction so as not to collide with the sample surface 2a. The position Za in the z direction that is separated from the sample surface 2a by the predetermined distance is set in advance. The probe 5 at the time of scanning in the x and y directions is vibrating at the vibration amplitude A as shown by the vibration waveform W1 shown in FIG.
[0029]
Next, the Z drive unit 22 moves the probe 5 above the measurement point 201 in the z direction to approach the sample surface 2a. Thus, when the probe 5 approaches or comes into contact with the sample surface 2a, the vibration amplitude of the probe 5 attenuates to the vibration amplitude A 'as shown in a vibration waveform W2 shown in FIG. The amplitude attenuation detection unit 16 calculates the degree of attenuation “A−A ′” of the vibration amplitude and compares it with a preset threshold Th1, and when the degree of attenuation “AA ′” reaches the threshold Th1, This is notified to the control unit 24. Upon receiving this notification, the control unit 24 instructs the Z drive unit 22 to stop moving. Thus, the probe 5 stops before a force large enough to damage the probe 5 and the sample 2, so that the probe 5 and the sample 2 are not damaged. When the movement of the probe 5 is instructed to stop, observation data in the z direction of the measurement point 201 is collected.
[0030]
Next, the control unit 24 moves the probe 5 in the z direction to the position Za. When the probe 5 reaches the position Za, the XY drive unit 20 causes the probe 5 to scan in the x and y directions to a position above the next measurement point 201.
By repeatedly performing the scanning in the x and y directions and the movement in the z direction, scanning of the sample surface 2a is performed, and observation data of each measurement point 201 is collected.
[0031]
Next, the configuration and operation of collecting observation data by the above scanning will be described.
In FIG. 1, the correction amount calculation unit 26 calculates a correction amount for correcting the position data of the probe 5 in the z direction. The Z data calculation unit 28 detects the position of the probe 5 in the z direction at the time when the probe 5 stops based on the drive data of the Z drive unit 22, and obtains the position data by the correction amount calculation unit 26. The corrected amounts are summed to obtain observation data in the z direction.
[0032]
The image data generation unit 30 combines the observation data in the z direction obtained by the Z data calculation unit 28 with the drive data used for scanning in the x and y directions by the XY drive unit 20 to generate three-dimensional image data. Generate This image data is reproduced and displayed as a three-dimensional image by the display unit 32.
[0033]
With reference to FIG. 4, the correction processing of the correction amount calculation unit 26 and the Z data calculation unit 28 will be described. FIG. 4 shows a waveform of a displacement corresponding to the position of the probe 5 in the z direction.
As shown in FIG. 4, when the probe 5 reaches the position Z0 near the sample surface 2a, a force acts on the probe 5, and the vibration amplitude starts to attenuate. Then, it is assumed that the degree of attenuation of the vibration amplitude reaches a preset threshold Th1 at the position Z1. At this point, the control unit 24 instructs the Z drive unit 22 to stop the movement in the z direction, whereby the operation of the probe 5 approaching the sample surface 2a is stopped. However, the approach operation of the probe 5 continues for the response time from the time of the movement stop instruction to the stop of the probe 5, so that the probe 5 actually stops at the position Z2. If the position data of the position Z2 is used as the observation data in the z direction as it is, the difference ΔZ between the positions Z1 and Z2 becomes “fluctuation in the amount of approach”, which is an error factor of the observation data in the z direction. In the present embodiment, correct observation data in the z direction is obtained by correcting the difference ΔZ by the position data of the position Z2.
[0034]
In FIG. 4, the difference ΔA between the amplitude A1 at the position Z1 and the amplitude A2 at the position Z2 is equal to the difference ΔZ because it is the length in the z direction. Accordingly, if the difference ΔA is obtained, the above correction of the position data of the position Z2 can be performed. Therefore, the amplitude attenuation detection unit 16 outputs the vibration amplitude when the degree of attenuation of the vibration amplitude reaches the threshold Th1, that is, the amplitude A1 at the position Z1, to the correction amount calculation unit 26. Further, the vibration amplitude when the approaching operation of the probe 5 is stopped, that is, the amplitude A2 of the position Z2 is output to the correction amount calculation unit 26. As a result, the correction amount calculation unit 26 can obtain the amplitude A1 of the position Z1 and the amplitude A2 of the position Z2, obtain the difference ΔA between the amplitudes A1 and A2, set the correction amount ΔZ, and use the correction amount ΔZ as Z data. Output to the calculation unit 28. The Z data calculation unit 28 sums the correction amount ΔZ and the position data of the position Z2 obtained from the Z drive unit 22, and uses the sum as observation data in the z direction. This makes it possible to collect corrected observation data in the accurate z direction.
[0035]
Note that the control unit 24 may control the movement in the z direction such that the degree of attenuation of the vibration amplitude of the probe 5 after the approach stop of the probe 5 is constant at the threshold Th1. By doing so, the probe 5 substantially maintains the position Z1 at which the degree of attenuation of the vibration amplitude has reached the threshold Th1, so that accurate observation data in the z direction can be collected without the above correction. Further, in order to further improve the accuracy of the observation data in the z direction, it may be combined with the above correction.
[0036]
Next, a second embodiment will be described with reference to FIG. FIG. 5 is a block diagram showing a configuration of a sampling scanning probe microscope according to the second embodiment of the present invention. In FIG. 5, portions corresponding to the respective portions in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.
In the sampling scanning probe microscope according to the second embodiment, the movement of the probe 5 in the z direction is controlled based on the degree of change in the phase of the vibration of the probe 5. As shown in FIG. 5, the sampling scanning probe microscope according to the second embodiment includes a phase change detection unit 41. The phase change detection unit 41 detects the degree of change in the phase of the vibration of the probe 5. As the phase change degree, an actual change amount may be used, or a change rate may be used. The phase change detection unit 41 compares the degree of change of the phase with a preset threshold Th2, and notifies the control unit 24 when the degree of change reaches the threshold Th2. Thus, the control unit 24 controls the movement of the Z drive unit 22 in the z direction, as in the first embodiment.
[0037]
In the second embodiment, the image data generator 30 detects the position of the probe 5 in the z direction based on the drive data of the Z data driver 22 at the time when the approach between the probe 5 and the sample surface 2a stops. Then, this position data is used as observation data in the z direction.
[0038]
In the second embodiment, the control unit 24 controls the movement in the z direction after the approach and stop of the probe 5 so that the degree of change in the phase of the vibration of the probe 5 is constant at the threshold Th2. Is preferred. By doing so, the probe 5 substantially maintains the position where the degree of change in the phase of the vibration has reached the threshold Th2, so that accurate observation data in the z direction can be collected.
[0039]
Next, a third embodiment will be described with reference to FIG. FIG. 6 is a block diagram showing a configuration of a sampling scanning probe microscope according to the third embodiment of the present invention. In FIG. 6, parts corresponding to the respective parts in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.
In the sampling scanning probe microscope according to the third embodiment, the movement of the probe 5 in the z direction is controlled based on the degree of change in the frequency of vibration of the probe 5. As shown in FIG. 6, the sampling scanning probe microscope according to the third embodiment includes a phase adjuster 51, an amplifier 52, and a frequency / voltage converter (FV converter) 53. The phase adjuster 51 adjusts the output of the cantilever displacement detector 10 so that the cantilever 6 vibrates at the resonance frequency and outputs the output to the amplifier 52. The amplifier 52 amplifies the input signal with a predetermined amplification degree and outputs the signal to the bimorph 8 and the FV converter 53. The bimorph 8 vibrates the cantilever 6 and the probe 5 according to the input signal.
[0040]
The FV converter 53 converts the frequency of the signal input from the amplifier 52 into a corresponding voltage signal and outputs the voltage signal to the control unit 24. The control unit 24 detects the degree of change in the vibration frequency of the probe 5 based on the input voltage signal. As the frequency change degree, an actual change amount may be used, or a change rate may be used. The control unit 24 compares the degree of change of the frequency with a preset threshold Th3, and when the degree of change reaches the threshold Th3, the control unit 24 sends a signal to the Z drive unit 22 in the same manner as in the first embodiment. To control the movement in the z direction.
[0041]
In the third embodiment, similarly to the second embodiment, the image data generating unit 30 generates the image data based on the drive data of the Z data drive unit 22 at the time when the approach between the probe 5 and the sample surface 2a stops. The position of the probe 5 in the z direction is detected, and this position data is used as observation data in the z direction.
[0042]
In the third embodiment, the control unit 24 controls the movement in the z direction after the approach and stop of the probe 5 so that the degree of change in the frequency of the vibration of the probe 5 becomes constant at the threshold Th3. Is preferred. By doing so, the probe 5 substantially maintains the position where the degree of change in the vibration frequency has reached the threshold value Th3, so that accurate observation data in the z direction can be collected.
[0043]
In the above-described first to third embodiments, the scanning of the probe 5 in the x and y directions and the movement in the z direction are performed by the three-dimensional actuator 14. However, the scanning in the x and y directions and the movement in the z direction are performed. May be performed relatively to the sample surface of the sample 2. For example, the scanning in the x and y directions and the movement in the z direction may be performed by moving the sample table 4.
[0044]
Also, as shown in FIG. 2, the operation of approaching and separating the probe 5 and the sample surface 2a is linear movement, but the operation of approaching or separating is performed during movement in the x and y directions, so that the probe 5 A curve may be moved in the z direction. However, in order to accurately detect changes in amplitude, phase, and frequency of vibration of the probe 5, it is preferable to perform linear movement.
[0045]
Further, the speed of the linear movement when the probe 5 approaches the sample surface 2a may be different from the speed of the linear movement when the probe 5 is separated from the sample surface 2a. In this case, it is preferable that the speed at the time of separation be higher than the speed at the time of approach. The reason for this is that the measurement time can be shortened by increasing the speed when the probe 5 is separated, even if the change in amplitude, phase, and frequency of the vibration of the probe 5 can be accurately detected when approaching. .
[0046]
Note that the speed of the linear movement of the probe 5 in the z direction may be decelerated in at least one of the operation of moving the probe 5 closer to and the distance from the sample surface 2a. Preferably, deceleration control when approaching is good for accurately detecting changes in amplitude, phase, and frequency of vibration of the probe 5.
[0047]
The linear movement speed of the probe 5 in the z-direction is preferably set to 1 micrometer or more per second from the viewpoint of shortening the measurement time. Further, the thickness is preferably 2 micrometers or more per second, and more preferably 4 micrometers or more per second. Further, when the thickness is 6 micrometers or more per second, the measurement time can be significantly reduced.
[0048]
In the above-described first to third embodiments, the displacement of the probe portion is detected by the light detection type cantilever, but a cantilever other than the light detection type may be used. For example, it is also possible to use a self-detection lever for detecting the amount of displacement of the self.
[0049]
As described above, the embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes a design change or the like without departing from the gist of the present invention.
[0050]
【The invention's effect】
As described above, according to the present invention, it is possible to prevent the probe and the sample from being damaged by collision between the probe and the sample. In addition, since the probe can be brought close to or in contact with the sample at a high speed, the measurement time can be reduced. This makes it possible to easily perform measurement of a sample having severe irregularities and measurement of a large area.
[0051]
In addition, since the observation data is collected by correcting the "fluctuation of the approach amount" corresponding to the response time when the approach between the probe and the sample surface is stopped, more accurate measurement can be performed.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a sampling scanning probe microscope according to a first embodiment of the present invention.
FIG. 2 is a conceptual diagram for explaining a scanning method according to the present invention.
FIG. 3 is a vibration waveform diagram for explaining a degree of attenuation of a vibration amplitude of a probe 5;
FIG. 4 is a vibration waveform diagram for explaining a correction process of a correction amount calculation unit 26 and a Z data calculation unit 28 shown in FIG.
FIG. 5 is a block diagram showing a configuration of a sampling scanning probe microscope according to a second embodiment of the present invention.
FIG. 6 is a block diagram showing a configuration of a sampling scanning probe microscope according to a third embodiment of the present invention.
[Explanation of symbols]
2 ... sample, 2a ... sample surface, 4 ... sample stage, 5 ... probe, 6 ... cantilever, 8 ... bimorph, 9 ... laser beam, 10 ... cantilever displacement detector, 12 ... laser generator, 14 ... 3D actuator , 16: Amplitude attenuation detection unit, 18: excitation power supply, 20: XY drive unit, 22: Z drive unit, 24: control unit, 26: correction amount calculation unit, 28: Z data calculation unit, 30: image data generation Unit, 32 display unit, 41 phase change detection unit, 51 phase adjuster, 52 amplifier, 53 frequency / voltage converter (FV converter)

Claims

In a sampling scanning probe microscope equipped with a probe capable of scanning in the x and y directions parallel to the sample surface and moving in the z direction perpendicular to the sample surface relative to the sample surface,
Means for vibrating the probe at a vibration frequency that resonates or forcibly vibrates the probe,
Means for collecting observation data at the time when the probe approaches or contacts the surface of the sample,
Means for detecting the degree of attenuation of the vibration amplitude of the probe at the time when the probe approaches or contacts the sample surface,
Control means for controlling the movement in the z direction,
The control means stops the approach between the probe and the sample surface when the detected degree of attenuation reaches a preset threshold value, and after the approach stop, the next scanning period in the x or y direction. A sampling scanning probe microscope, wherein the probe is separated from the sample surface by a predetermined distance such that the probe does not come into contact with the sample surface.

The sampling scan according to claim 1, wherein the control unit controls the movement in the z direction such that the degree of attenuation of the vibration amplitude of the probe becomes constant at the threshold after the approach stop. Probe microscope.

In a sampling scanning probe microscope equipped with a probe capable of scanning in the x and y directions parallel to the sample surface and moving in the z direction perpendicular to the sample surface relative to the sample surface,
Means for vibrating the probe at a vibration frequency that resonates or forcibly vibrates the probe,
Means for collecting observation data at the time when the probe approaches or contacts the surface of the sample,
Means for detecting the degree of change in the phase of vibration of the probe at the time when the probe approaches or comes into contact with the sample surface,
Control means for controlling the movement in the z direction,
The control means stops the approach between the probe and the sample surface when the detected degree of change reaches a preset threshold value, and after the approach stop, the next scanning period in the x or y direction. A sampling scanning probe microscope, wherein the probe is separated from the sample surface by a predetermined distance such that the probe does not come into contact with the sample surface.

4. The sampling according to claim 3, wherein the control unit controls the movement in the z direction so that a degree of change in the phase of vibration of the probe after the approach stop is constant at the threshold value. Scanning probe microscope.

In a sampling scanning probe microscope equipped with a probe capable of scanning in the x and y directions parallel to the sample surface and moving in the z direction perpendicular to the sample surface relative to the sample surface,
Means for vibrating the probe at a vibration frequency that resonates or forcibly vibrates the probe,
Means for collecting observation data at the time when the probe approaches or contacts the surface of the sample,
Means for detecting the degree of change in the frequency of vibration of the probe at the time when the probe approaches or comes into contact with the sample surface,
Control means for controlling the movement in the z direction,
The control means stops the approach between the probe and the sample surface when the detected degree of change reaches a preset threshold value, and after the approach stop, the next scanning period in the x or y direction. A sampling scanning probe microscope, wherein the probe is separated from the sample surface by a predetermined distance such that the probe does not come into contact with the sample surface.

6. The sampling according to claim 5, wherein the control unit controls the movement in the z direction such that the degree of change in the frequency of vibration of the probe after the approach stop is constant at the threshold. Scanning probe microscope.

7. The method according to claim 1, wherein a position in the z direction of the probe at the time when the approach between the probe and the sample surface is stopped is detected, and the position data is used as observation data in the z direction. The sampling scanning probe microscope according to any one of the above items.

Detecting the position of the probe in the z direction at the time when the approach between the probe and the sample surface is stopped, based on the difference between the attenuation degree of the vibration amplitude of the probe at the time of the stop and the threshold. Means for correcting the detected position,
The sampling scanning probe microscope according to claim 1, wherein the corrected position data is observation data in a z direction.

The three-dimensional image data is generated by combining the observation data in the z direction and the driving data used in the scanning in the x and y directions, and an image is displayed using the image data. A sampling scanning probe microscope according to claim 8.

The sampling scanning probe microscope according to any one of claims 1 to 9, wherein the operation of bringing the probe and the surface of the sample closer and the operation of separating the probe are linear movements.

The sampling scanning probe microscope according to claim 10, wherein a speed of the linear movement when approaching the probe and the sample surface is different from the speed when separating the probe.

The sampling scanning probe microscope according to claim 11, wherein the speed at the time of separation is higher than the speed at the time of approach.

The sampling scanning probe microscope according to claim 10, wherein a speed of the linear movement is controlled to be reduced in at least one of an operation of moving the probe and the surface of the sample closer to or away from the surface of the sample.

13. The sampling scanning probe microscope according to claim 10, wherein a speed of the linear movement is 1 micrometer per second or more.

The sampling scanning probe microscope according to any one of claims 10 to 12, wherein the speed of the linear movement is 2 micrometers or more per second.

13. The sampling scanning probe microscope according to claim 10, wherein the speed of the linear movement is 4 micrometers or more per second.

The sampling scanning probe microscope according to any one of claims 10 to 12, wherein a speed of the linear movement is 6 micrometers or more per second.

A probe for performing scanning in the x and y directions parallel to the sample surface and movement in the z direction perpendicular to the sample surface relative to the sample surface, and resonating the probe with the probe or Vibration at a vibration frequency forcibly vibrating, a scanning method in a sampling scanning probe microscope to collect observation data at the time when the probe approaches or contacts the surface of the sample,
A step of detecting the degree of attenuation of the vibration amplitude of the probe at the time when the probe approaches or contacts the sample surface,
When the detected degree of attenuation reaches a preset threshold, a step of stopping the approach between the probe and the sample surface,
After stopping the approach, separating the probe from the sample surface to a predetermined distance such that the probe does not contact the sample surface during the next scanning period in the x or y direction,
A scanning method comprising:

A probe for performing scanning in the x and y directions parallel to the sample surface and movement in the z direction perpendicular to the sample surface relative to the sample surface, and resonating the probe with the probe or Vibration at a vibration frequency forcibly vibrating, a scanning method in a sampling scanning probe microscope to collect observation data at the time when the probe approaches or contacts the surface of the sample,
A step of detecting the degree of change in the phase of vibration of the probe when the probe approaches or comes into contact with the sample surface;
When the detected degree of change reaches a preset threshold, stopping the approach between the probe and the sample surface,
After stopping the approach, separating the probe from the sample surface to a predetermined distance such that the probe does not contact the sample surface during the next scanning period in the x or y direction,
A scanning method comprising:

A probe for performing scanning in the x and y directions parallel to the sample surface and movement in the z direction perpendicular to the sample surface relative to the sample surface, and resonating the probe with the probe or Vibration at a vibration frequency forcibly vibrating, a scanning method in a sampling scanning probe microscope to collect observation data at the time when the probe approaches or contacts the surface of the sample,
Detecting the degree of change in the frequency of vibration of the probe at the time when the probe approaches or comes into contact with the sample surface,
When the detected degree of change reaches a preset threshold, stopping the approach between the probe and the sample surface,
After stopping the approach, separating the probe from the sample surface to a predetermined distance such that the probe does not contact the sample surface during the next scanning period in the x or y direction,
A scanning method comprising: