JP2611200B2

JP2611200B2 - Particle beam mapping equipment

Info

Publication number: JP2611200B2
Application number: JP61128761A
Authority: JP
Inventors: 暉士平居
Original assignee: Shimadzu Corp
Current assignee: Shimadzu Corp
Priority date: 1986-06-03
Filing date: 1986-06-03
Publication date: 1997-05-21
Anticipated expiration: 2012-05-21
Also published as: JPS62285353A

Description

【発明の詳細な説明】イ．産業上の利用分野本発明は、電子線，イオンビーム，中性子ビーム等の
粒子線で試料を励起し、試料より発生する信号を用い
て、試料表面の元素分布等の特性を分析する粒子線マッ
ピング装置に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to particle beam mapping in which a sample is excited by a particle beam such as an electron beam, an ion beam, or a neutron beam, and characteristics such as element distribution on a sample surface are analyzed using a signal generated from the sample. Related to the device.

ロ．従来の技術粒子線で試料面を走査して、試料面を構成する各画素
毎に、試料から発生する信号を計測し、これを処理表示
するマッピング法は、分析方法として非常に有効な手法
であるが、点分析や線分析法等他の分析法とは異なっ
て、面分析であるから測定に長時間を要する。通常これ
らの手法は市販のマイクロアナライザ等で行う場合が多
く、数時間以上の測定では、粒子線の照射強度の安定度
が分析結果に影響する場合が多い。B. 2. Description of the Related Art A mapping method that scans a sample surface with a particle beam, measures a signal generated from the sample for each pixel constituting the sample surface, and processes and displays the signal is a very effective analysis method. However, unlike other analysis methods such as point analysis and line analysis, measurement requires a long time because it is a surface analysis. Usually, these methods are often performed with a commercially available microanalyzer or the like, and in the case of measurement for several hours or more, the stability of the irradiation intensity of the particle beam often affects the analysis result.

従来、粒子線の照射強度の変動が分析結果に影響する
場合、測定誤差の補正法としては２通りの方法が行われ
ている。即ち、照射ビームそのものを測定して照射強度
の変化を検出する方法（照射ビーム電流等）と照射され
た試料が受けた量（吸収電流等）を測定して照射強度の
変化を検出する方法である。Conventionally, when a variation in the irradiation intensity of a particle beam affects the analysis result, two methods are used as a method for correcting a measurement error. That is, a method of measuring a change in irradiation intensity by measuring the irradiation beam itself (irradiation beam current and the like) and a method of measuring a change in irradiation intensity by measuring the amount (absorption current and the like) received by an irradiated sample. is there.

前者の場合には、正しい補正が行えるが、照射ビーム
の照射強度の測定中には、そのビームを試料へ照射する
ことは出来ず、試料への照射率が低下して、分析効率の
低下を招く。また後者は試料照射中も平行して測定でき
るが、試料の組成の変化によって吸収電流等は変動する
為に、正確に補正が出来ない。In the former case, correct correction can be performed, but during the measurement of the irradiation intensity of the irradiation beam, the beam cannot be irradiated on the sample, and the irradiation rate on the sample decreases, and the analysis efficiency decreases. Invite. The latter can be measured in parallel during irradiation of the sample, but cannot be accurately corrected because the absorption current and the like fluctuate due to a change in the composition of the sample.

また、前者の方法では本測定と較正測定との間に時間
的ズレが発生し、後者の方法では間接的測定であるため
に、どちらの測定方法においても、照射強度の変化を正
確に把握出来ないために、試料面の微量な変化を測定す
ることが出来ないと云う問題があった。In addition, the former method causes a time lag between the main measurement and the calibration measurement, and the latter method is an indirect measurement. For this reason, there is a problem that it is not possible to measure a minute change on the sample surface.

ハ．発明が解決しようとする問題点本発明は、測定時間中の照射強度の変化を正確に把握
することにより、試料面の微量な変化でも正確に測定で
きるようにすることを目的とする。C. Problems to be Solved by the Invention It is an object of the present invention to accurately grasp even a minute change in a sample surface by accurately grasping a change in irradiation intensity during a measurement time.

ニ．問題点解決のための手段電子線，イオンビーム，中性子ビーム等の粒子線で試
料を励起し、試料より発生する信号を用いて、試料表面
の元素分布等の特性を分析する粒子線マッピング装置に
おいて、試料を励起する手段と、上記励起線による試料
面走査の走査線と交差する方向に延びて、被測定試料の
走査域に臨むよう、表面の材質が均一な基準試料を保持
する手段と、上記２つの試料から放出される信号を検出
する手段と、被測定試料の測定期間中の励起線走査の一
走査線毎に得られる上記基準試料から放出される信号の
検出値から走査線毎に励起線の強度に対応するデータを
得て、上記走査線に沿う被測定試料から放出される信号
の検出値を励起線強度の一定値に対応する値に変換する
補正手段を設けた。D. Means for solving problems In a particle beam mapping device that excites a sample with a particle beam such as an electron beam, ion beam, or neutron beam, and analyzes characteristics such as element distribution on the sample surface using signals generated from the sample. Means for exciting the sample, means for extending a direction intersecting with the scanning line for scanning the sample surface by the excitation line, and means for holding a reference sample having a uniform surface material so as to face the scanning area of the sample to be measured, Means for detecting signals emitted from the two samples, and for each scan line from a detection value of a signal emitted from the reference sample obtained for each scan line of the excitation line scan during the measurement period of the sample to be measured. Correction means is provided for obtaining data corresponding to the intensity of the excitation line and converting a detected value of a signal emitted from the sample to be measured along the scanning line into a value corresponding to a constant value of the excitation line intensity.

ホ．作用粒子線で試料面を走査して、試料面を構成する各画素
毎に、試料から発生する信号を計測し、これを処理表示
するマッピング法において、一定組成の均一基準試料面
に粒子線を照射して、同基準試料から発生する信号を検
出すれば、その検出値は照射粒子線強度に比例する。本
発明は、この基準試料から発生する信号強度が照射粒子
線強度に比例することを利用して、基準試料から発生す
る信号強度を検出することにより、照射粒子線強度の変
化を把握しようとするものであり、基準試料板として、
マッピング領域の端に臨んで、照射粒子線強度を測定す
る基準試料（表面に材質が均一な物質を塗布するか、張
り付けてある板）を設置し、マッピング時に、上記基準
試料を含むように面走査を行うことにより、各走査線毎
に基準試料から照射粒子線の強度変化の情報を入手でき
るから、照射粒子線強度の変化をほぼ連続的に把握する
ことが可能になり、試料面の微弱な変化を励起線の変動
の影響に埋没させることなく正確に把握出来るようにな
った。E. In a mapping method that scans the sample surface with a particle beam, measures the signal generated from the sample for each pixel constituting the sample surface, and processes and displays the signal, the particle beam is applied to a uniform reference sample surface of a fixed composition. If a signal generated from the reference sample is detected by irradiation, the detected value is proportional to the intensity of the irradiated particle beam. The present invention uses the fact that the signal intensity generated from the reference sample is proportional to the irradiation particle beam intensity, and detects the signal intensity generated from the reference sample, thereby trying to grasp the change in the irradiation particle beam intensity. And as a reference sample plate,
At the end of the mapping area, a reference sample for measuring the intensity of the irradiated particle beam (a plate coated with a uniform material on the surface or attached) is installed. By performing scanning, information on the intensity change of the irradiation particle beam can be obtained from the reference sample for each scanning line, so that the change in the irradiation particle beam intensity can be grasped almost continuously, and the weakness of the sample surface can be obtained. It is now possible to accurately grasp such changes without being buried in the effects of fluctuations in the excitation line.

ヘ．実施例第１図に本発明の要部である試料ステージ付近の一実
施例を示す。第２図に本発明の一実施例のブロック図を
示す。第１図及び第２図において、Ｓは試料、Ｒは試料
Ｓを励起させて電子線或はＸ線を放出させる粒子線、１
は粒子線測定板で表面に基準試料として材質の均一な物
質を塗布又は張り付けられたコ字型の板である。試料ホ
ルダー２は試料Ｓを止めネジ2aで保持し、粒子線測定板
１を止めビス1aで試料走査線の一方の端で試料Ｓの測定
域に臨ませて保持する。３は試料ステージで止めビス3a
で試料ホルダー２を保持し、CPU9の駆動信号に基づい
て、ステージ駆動装置８で１画素ピッチ単位でＸ軸方向
及ぶＹ軸方向に移動させられる。４はＸ線分光器で試料
Ｓから放出されたＸ線を分光する。５は分光器４で分光
されたＸ線を検出する検出器。スケーラ７は検出器５か
ら送られてくる信号を計数する。９はCPUでステージ駆
動装置８に、試料ステージ３を１画素ピッチ単位で、Ｘ
軸方向及ぶＹ軸方向に移動させるための駆動信号を出力
し、またその駆動信号で試料Ｓの測定位置を把握する。
また試料Ｓが測定位置で信号を測定する時間だけ、ゲー
ト回路６に信号を送ってゲート回路６を開（ON）状態と
して、検出器５で検出される信号をスケーラ７で計数さ
せ、その計数値に試料Ｓの測定位置を付加して記憶し、
測定位置により取り込んだスケーラ７の計数データが粒
子線測定板１から放出された信号によるものであること
を検知して、粒子線強度の変化を測定し、試料ＳのＸ軸
方向一走査毎に測定値の補正を行う。10は表示装置で、
CPU9から送られる信号を表示する。F. Embodiment FIG. 1 shows an embodiment in the vicinity of a sample stage which is a main part of the present invention. FIG. 2 shows a block diagram of one embodiment of the present invention. 1 and 2, S is a sample, R is a particle beam that excites the sample S and emits an electron beam or X-ray,
Is a U-shaped plate, which is a particle beam measuring plate and a substance of uniform material is applied or stuck on the surface as a reference sample. The sample holder 2 holds the sample S with a set screw 2a, and holds the particle beam measurement plate 1 with a set screw 1a so as to face the measurement area of the sample S at one end of the sample scanning line. 3 is a sample stage and a stop screw 3a
Then, the sample holder 2 is held, and is moved in the Y-axis direction extending in the X-axis direction in units of one pixel pitch by the stage driving device 8 based on the drive signal of the CPU 9. Reference numeral 4 denotes an X-ray spectroscope for separating X-rays emitted from the sample S. Reference numeral 5 denotes a detector that detects X-rays separated by the spectroscope 4. The scaler 7 counts signals sent from the detector 5. Numeral 9 denotes a CPU which controls the stage driving device 8 to move the sample stage 3 in units of one pixel pitch, X
A drive signal for moving in the axial direction and the Y-axis direction is output, and the measurement position of the sample S is grasped by the drive signal.
Further, the signal is sent to the gate circuit 6 for the time when the sample S measures the signal at the measurement position, the gate circuit 6 is opened (ON), and the signal detected by the detector 5 is counted by the scaler 7. The measurement position of the sample S is added to the numerical value and stored,
It detects that the count data of the scaler 7 taken in at the measurement position is based on the signal emitted from the particle beam measurement plate 1 and measures the change in the particle beam intensity. Correct the measured value. 10 is a display device,
Displays the signal sent from CPU9.

以上の構成で、本発明の要部である粒子線の照射強度
の変化に対する、測定値の補正動作について説明する。
第３図に示すような測定域Ｃをマッピングする場合、測
定域Ｃに近接させて粒子線測定板１をセットして、１つ
のＸ軸走査線Ｄ毎に粒子線測定板１上も走査して線分析
を行い、次にＹ軸方向に１ピッチ走査線をずらして走査
を行い、測定域Ｃの全域を走査して面分析を行う。測定
板１の表面には材質が均一な物質が基準試料として塗布
又は張り付けてあるから、測定板１から放出されるＸ線
は照射される粒子線強度と比例している。粒子線の照射
（測定）位置をステージ駆動装置８に送る駆動信号によ
り検知し、その測定位置における検出値をCPU9に記憶す
る。その記憶したデータから測定板１のデータを抽出し
て粒子線の照射強度変化を測定し、そのデータの属する
Ｘ軸走査線毎にデータを補正する。With the above configuration, an operation of correcting a measured value with respect to a change in irradiation intensity of a particle beam, which is a main part of the present invention, will be described.
When mapping the measurement area C as shown in FIG. 3, the particle beam measurement plate 1 is set close to the measurement area C, and the particle beam measurement plate 1 is also scanned for each X-axis scanning line D. Then, scanning is performed by shifting the scanning line by one pitch in the Y-axis direction, and the entire area of the measurement area C is scanned for surface analysis. Since a material having a uniform material is applied or stuck on the surface of the measurement plate 1 as a reference sample, the X-ray emitted from the measurement plate 1 is proportional to the intensity of the particle beam irradiated. The irradiation (measurement) position of the particle beam is detected by a drive signal sent to the stage driving device 8, and the detected value at the measurement position is stored in the CPU 9. The data of the measurement plate 1 is extracted from the stored data, the change in the irradiation intensity of the particle beam is measured, and the data is corrected for each X-axis scanning line to which the data belongs.

512×512画素のマッピングを行う場合、１画素の測定
時間を10msecとすると、全面の測定には40分以上かかる
が、一本のＸ軸走査線の所要時間は約5secであるから、
この程度の時間間隔で測定しておけば、粒子線の照射強
度変化を充分正確に把握することが可能である。When performing the mapping of 512 × 512 pixels, assuming that the measurement time of one pixel is 10 msec, the measurement of the entire surface takes 40 minutes or more, but the time required for one X-axis scanning line is about 5 seconds.
If the measurement is performed at such a time interval, it is possible to grasp the irradiation intensity change of the particle beam sufficiently accurately.

ト．効果本発明によれば、励起線による試料面走査の走査線と
交差する方向に延びて被測定試料の走査域に臨むよう表
面の材質が均一な基準試料を設け、励起線走査の一走査
線毎に励起線の強度に対応するデータを得て被測定試料
からの信号を補正するので、粒子線の照射強度変化を略
リアルタイムに正確に検出し、励起線強度の変動の影響
を受けないように測定試料からの信号を補正することが
可能になった。したがって、試料表面の微細な変化に対
する情報が把握できるようになったので、一段とマッピ
ング分析における測定精度が向上した。G. According to the present invention, a reference sample having a uniform surface material is provided so as to extend in a direction intersecting with a scanning line for scanning a sample surface by an excitation line so as to reach a scanning area of a sample to be measured, and one scanning line for excitation line scanning is provided. Since data corresponding to the intensity of the excitation beam is obtained every time and the signal from the sample to be measured is corrected, the change in the irradiation intensity of the particle beam is accurately detected almost in real time, so that it is not affected by the fluctuation of the excitation beam intensity It became possible to correct the signal from the measurement sample. Therefore, since information on minute changes in the sample surface can be grasped, measurement accuracy in the mapping analysis is further improved.

また、本発明においては、粒子線強度を検出するのに
粒子線光学系に特別なモニタ装置などを必要としないの
で構成が簡単であり、安価に実現することができる。Further, in the present invention, a special monitoring device or the like is not required for the particle beam optical system to detect the particle beam intensity, so that the configuration is simple and can be realized at low cost.

【図面の簡単な説明】[Brief description of the drawings]

第１図は本発明の要部の一実施例の斜視図、第２図は本
発明の一実施例のブロック図、第３図は測定域の説明図
である。FIG. 1 is a perspective view of one embodiment of a main part of the present invention, FIG. 2 is a block diagram of one embodiment of the present invention, and FIG. 3 is an explanatory diagram of a measurement area.

Claims

(57)【特許請求の範囲】(57) [Claims]

【請求項１】試料を励起線にて照射しつつ試料面を走査
する手段と、上記励起線による試料面走査の走査線と交
差する方向に延びて、被測定試料の走査域に臨むよう、
表面の材質が均一な基準試料を保持する手段と、上記２
つの試料から放出される信号を検出する手段と、被測定
試料の測定期間中の励起線走査の一走査線毎に得られる
上記基準試料から放出される信号の検出値から走査線毎
に励起線の強度に対応するデータを得て、上記走査線に
沿う被測定試料から放出される信号の検出値を励起線強
度の一定値に対応する値に変換する補正手段を設けたこ
とを特徴とする粒子線マッピング装置。1. A means for scanning a sample surface while irradiating the sample with an excitation line, and extending in a direction intersecting a scanning line for scanning the sample surface by the excitation line so as to face a scanning area of the sample to be measured.
Means for holding a reference sample having a uniform surface material;
Means for detecting signals emitted from the two samples, and an excitation line for each scanning line from a detection value of a signal emitted from the reference sample obtained for each scanning line of the excitation line scanning during the measurement period of the sample to be measured. Correction means for obtaining data corresponding to the intensity of the light, and converting a detected value of a signal emitted from the sample to be measured along the scanning line into a value corresponding to a constant value of the excitation line intensity. Particle beam mapping device.