JPS6257064B2 - - Google Patents
Info
- Publication number
- JPS6257064B2 JPS6257064B2 JP56028108A JP2810881A JPS6257064B2 JP S6257064 B2 JPS6257064 B2 JP S6257064B2 JP 56028108 A JP56028108 A JP 56028108A JP 2810881 A JP2810881 A JP 2810881A JP S6257064 B2 JPS6257064 B2 JP S6257064B2
- Authority
- JP
- Japan
- Prior art keywords
- component
- sample
- signal
- electron beam
- amplitude value
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000010894 electron beam technology Methods 0.000 claims description 14
- 238000001514 detection method Methods 0.000 claims description 5
- 239000002245 particle Substances 0.000 claims description 5
- 230000005284 excitation Effects 0.000 description 8
- 230000000875 corresponding effect Effects 0.000 description 5
- 239000003990 capacitor Substances 0.000 description 3
- 230000001276 controlling effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000000284 extract Substances 0.000 description 2
- 230000002596 correlated effect Effects 0.000 description 1
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
- H01J37/26—Electron or ion microscopes; Electron or ion diffraction tubes
- H01J37/28—Electron or ion microscopes; Electron or ion diffraction tubes with scanning beams
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
- H01J37/02—Details
- H01J37/22—Optical, image processing or photographic arrangements associated with the tube
Landscapes
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
Description
【発明の詳細な説明】
本発明は陰極線管に表示される試料像の輝度又
はコントラストを自動的に一定にする電子ビーム
装置に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electron beam device that automatically maintains constant brightness or contrast of a sample image displayed on a cathode ray tube.
走査型電子顕微鏡等においては、電子銃から射
出された電子ビームを細く集束し、該ビームで試
料上を二次元的に走査し、その時に試料から発生
する粒子、例えば二次電子を検出器で捕え、該検
出器の出力信号を陰極線管の輝度変調グリツドに
印加している。該陰極線管では前記試料上の二次
元的走査に同時した電子ビーム走査が行なわれて
いるので、該陰極線管画面上には、試料表面形状
に関する二次電子走査像が表示される。 In a scanning electron microscope, etc., an electron beam emitted from an electron gun is focused into a narrow beam, and the beam is scanned two-dimensionally over a sample. At that time, particles generated from the sample, such as secondary electrons, are detected by a detector. The output signal of the detector is applied to the brightness modulation grid of the cathode ray tube. Since the cathode ray tube performs electron beam scanning simultaneously with the two-dimensional scanning on the sample, a secondary electron scanned image of the sample surface shape is displayed on the cathode ray tube screen.
所で、試料から発生する粒子、例えば二次電子
の量が多いと検出器の出力信号のレベルが高くな
り、結果的に陰極線管に表示される試料像の輝度
が適正なレベルを越えて観察しにくくなる。又、
二次電子信号は直流成分と交流成分から成つてお
り、二次電子の量が多くなると相対的に交流成分
が増加し、試料像のコントラストが適正なレベル
を越えてしまう。 However, if the amount of particles generated from the sample, such as secondary electrons, is large, the level of the output signal from the detector will increase, and as a result, the brightness of the sample image displayed on the cathode ray tube may exceed the appropriate level. It becomes difficult to do. or,
The secondary electron signal consists of a DC component and an AC component, and as the amount of secondary electrons increases, the AC component increases relatively, causing the contrast of the sample image to exceed an appropriate level.
本発明は斯くの如き欠点を一掃する為になされ
たもので、新規な電子ビーム装置を提供するもの
である。 The present invention has been made to eliminate these drawbacks, and provides a new electron beam device.
添付図は本発明の一実施例を示した走査型電子
顕微鏡の概略図である。 The attached figure is a schematic diagram of a scanning electron microscope showing one embodiment of the present invention.
図中１は顕微鏡本体で、該本体の頂部に設けら
れた電子銃２より射出された電子ビームは、コン
デンサレンズ３及び対物レンズ４によつて試料５
上に細く集束されると同時に、走査信号発生回路
６から走査信号が送られている偏向コイル７によ
つて偏向されるので、該ビームは試料上を走査す
る。該走査によつて試料５から発生した粒子、例
えば二次電子は検出器８によつて検出される。該
検出器の出力は、増幅器９を介して陰極線管１０
の輝度変調グリツドＧへ印加される。該陰極線管
の偏向コイル１１には、前記走査信号発生回路６
から走査信号が前記顕微鏡本体１の偏向コイル７
へ送るのと同期して送られているので、該陰極線
管画面には試料表面形状に関する二次電子走査像
が表示される。 In the figure, reference numeral 1 denotes a microscope main body, and an electron beam emitted from an electron gun 2 installed at the top of the main body is passed through a condenser lens 3 and an objective lens 4 to a sample 5.
The beam is narrowly focused upward and simultaneously deflected by a deflection coil 7 to which a scanning signal is sent from a scanning signal generating circuit 6, so that the beam scans over the sample. Particles, such as secondary electrons, generated from the sample 5 by the scanning are detected by the detector 8. The output of the detector is passed through an amplifier 9 to a cathode ray tube 10.
is applied to the brightness modulation grid G. The deflection coil 11 of the cathode ray tube includes the scanning signal generation circuit 6.
A scanning signal is sent to the deflection coil 7 of the microscope main body 1.
Since it is sent in synchronization with the sending to the sample surface, a secondary electron scanned image of the sample surface shape is displayed on the cathode ray tube screen.
前記増幅器９の出力は、又ローパスフイルタ１
２及び振幅検出回路１３へ送られる。前者は増幅
器の出力、即ち二次電子信号の内、交流成分を減
衰させて直流成分だけを取り出し、後者は二次電
子信号の交流成分の振幅値（ピーク・ピーク値）
に対応した信号を取り出す。前者の出力はスイツ
チング回路１４の端子t1に、後者の出力はt2に
夫々送られる。これらの出力の内、何れかがスイ
ツチS1及び端子t3を介してコンデンサレンズ励磁
レベル制御回路１５の演算増幅器１６の正入力端
子に入力される。該コンデンサレンズ励磁レベル
制御回路は、前記コンデンサレンズ３の励磁レベ
ルをコントロールすることにより、試料５上に照
射される電子ビームの量をコントロールして、検
出器８に検出される二次電子の量を一定にするも
ので、前記第１スイツチング回路１４の出力信号
値を基準信号値と比較し、その差に対応した分だ
け前記コンデンサレンズ３の励磁電流値をコント
ロールする。即ち、前記演算増幅器１６の負入力
端子には、コントロールしたい二次電子信号の直
流レベル値に対応した電圧信号（この信号を第１
基準信号と称す）E1かコントロールしたい二次
電子信号の交流成分の振幅値に対応した電圧信号
（この信号を第２基準信号と称す）E2がスイツチ
S2の切換えによつて入力される。この切換えは前
記第１スイツチング回路１４のスイツチS1の切換
えに連動して行なわれる。S3はスイツチ、１７は
増幅器１８とコンデンサＣ及び抵抗Ｒから構成さ
れる信号値保持回路で、少なくともRCによつて
決定する時定数に対応した時間、スイツチS3を閉
じることにより前記演算増幅器１６の正入力端子
に入力された電圧信号値の第１又は第２基準信号
値に対する差に対応した電圧信号分がコンデンサ
Ｃに充電され、スイツチS3を開くことによつて該
信号分が維持される。又、視野を変えたり倍率を
変えた時に二次電子信号量が変わるので、その時
にスイツチS3を前記時間閉じれば、新たな差信号
がコンデンサＣに充電され、スイツチS3を開くと
該信号値が維持される。この維持された電子信号
はコンデンサレンズ励磁電源２０を通じて前記コ
ンデンサレンズ３の励磁電流をコントロールする
ので、試料５上に照射される電子ビーム量がコン
トロールされ、それに応じて二次電子の量が、前
記増幅器９の直流成分又は交流成分の振幅値が第
１基準値又は第２基準値に夫々等しくなるように
コントロールされる。 The output of the amplifier 9 is also passed through a low pass filter 1.
2 and the amplitude detection circuit 13. The former attenuates the AC component of the output of the amplifier, that is, the secondary electronic signal, and extracts only the DC component, and the latter measures the amplitude value (peak-to-peak value) of the AC component of the secondary electronic signal.
Extract the signal corresponding to. The output of the former is sent to terminal t1 of the switching circuit 14, and the output of the latter is sent to t2 . One of these outputs is input to the positive input terminal of the operational amplifier 16 of the condenser lens excitation level control circuit 15 via the switch S1 and the terminal t3 . The condenser lens excitation level control circuit controls the amount of electron beam irradiated onto the sample 5 by controlling the excitation level of the condenser lens 3, thereby controlling the amount of secondary electrons detected by the detector 8. The output signal value of the first switching circuit 14 is compared with the reference signal value, and the excitation current value of the condenser lens 3 is controlled by an amount corresponding to the difference. That is, the negative input terminal of the operational amplifier 16 is connected to a voltage signal (this signal is connected to the first
The voltage signal corresponding to the amplitude value of the alternating current component of the secondary electron signal that you want to control (this signal is called the second reference signal) E2 is the switch.
Input by switching S2 . This switching is performed in conjunction with the switching of switch S1 of the first switching circuit 14. S3 is a switch, and 17 is a signal value holding circuit composed of an amplifier 18, a capacitor C, and a resistor R. By closing the switch S3 for a time corresponding to a time constant determined by at least RC, the operational amplifier 16 The capacitor C is charged with a voltage signal corresponding to the difference between the voltage signal value input to the positive input terminal of the voltage signal and the first or second reference signal value, and this signal is maintained by opening the switch S3 . Ru. Also, when changing the field of view or changing the magnification, the amount of secondary electron signal changes, so if switch S3 is closed for the above period, a new difference signal will be charged in capacitor C, and when switch S3 is opened, this signal will be charged. Value is maintained. This maintained electronic signal controls the excitation current of the condenser lens 3 through the condenser lens excitation power supply 20, so the amount of electron beam irradiated onto the sample 5 is controlled, and the amount of secondary electrons is adjusted accordingly. The amplitude value of the DC component or AC component of the amplifier 9 is controlled to be equal to the first reference value or the second reference value, respectively.
この様な装置において、試料像の輝度を適正一
定レベルにすることを主眼とした場合、スイツチ
S1を端子t1に、スイツチS2を第１基準信号E1側に
切換え、二次電子信号の直流成分によつてコンデ
ンサレンズ３を通じて試料に照射される電子ビー
ム量をコントロールし、又試料像のコントラスト
を適正にすることを主眼とした場合、スイツチS1
を端子t2に、スイツチS2を第２基準信号E2側に切
換え、二次電子信号の交流成分の振幅値によつて
コンデンサレンズ３を通じて試料に照射される電
子ビーム量をコントロールすれば良いので、スイ
ツチS1及びS2の切換により、夫々陰極線管に表示
される試料像を所定の輝度或いは所定のコントラ
ストに保つことができる。但し、何れに主眼をお
いても、前述した様に輝度とコントラストは相関
関係にあるので、他の方も大方適正レベルに近づ
く。 In such a device, if the main objective is to maintain the brightness of the sample image at an appropriate constant level, the switch
S 1 is connected to terminal t 1 , switch S 2 is switched to the first reference signal E 1 side, and the amount of electron beam irradiated to the sample through the condenser lens 3 is controlled by the DC component of the secondary electron signal. If your main goal is to optimize the contrast of the image, switch S 1
to terminal t 2 and switch S 2 to the second reference signal E 2 side, and control the amount of electron beam irradiated to the sample through the condenser lens 3 based on the amplitude value of the AC component of the secondary electron signal. Therefore, by switching the switches S1 and S2 , the sample image displayed on the cathode ray tube can be maintained at a predetermined brightness or contrast, respectively. However, no matter which one is focused on, since brightness and contrast are correlated as described above, the other values will also approach appropriate levels.
尚、前記実施例では試料から発生する電子の
内、二次電子の信号を使用したが、この信号の代
わりに反射電子等他の粒子の信号を使用してもよ
い。 Incidentally, in the above embodiment, a signal of secondary electrons among the electrons generated from the sample was used, but a signal of other particles such as reflected electrons may be used instead of this signal.
添付図は本発明の一実施例を示した走査型電子
顕微鏡の概略図である。
２：電子銃、３：コンデンサレンズ、５：試
料、８：検出器、１０：陰極線管、１２：ローパ
スフイルタ、１３：振幅検出回路、１４：スイツ
チング回路、S1，S2，S3：スイツチ、１５：コン
デンサレンズ励磁レベル制御回路、１６：演算増
幅器、１７：信号値保持回路、２０：コンデンサ
レンズ励磁電源。
The attached figure is a schematic diagram of a scanning electron microscope showing one embodiment of the present invention. 2: Electron gun, 3: Condenser lens, 5: Sample, 8: Detector, 10: Cathode ray tube, 12: Low pass filter, 13: Amplitude detection circuit, 14: Switching circuit, S 1 , S 2 , S 3 : Switch , 15: condenser lens excitation level control circuit, 16: operational amplifier, 17: signal value holding circuit, 20: condenser lens excitation power supply.
Claims (1)
ムを細く集束し、該ビームで試料上を走査し、該
試料から発生した粒子を検出し、該検出信号を基
づいて陰極線管上に試料像を表示するようになし
た装置において、前記検出信号中の直流成分を検
出する手段と、前記検出信号中の交流成分の振幅
値を検出する手段と、該直流成分または交流成分
の振幅値を選択的に取り出すスイツチ手段を設
け、該スイツチ手段により直流成分が選択された
場合には該直流成分の第１基準信号に対する差に
基づいて試料上に照射される電子ビームの量をコ
ントロールし、交流成分の振幅値が選択された場
合には該振幅値の第２基準信号に対する差に基づ
いて試料上に照射される電子ビームの量をコント
ロールするようにしたことを特徴とする電子ビー
ム装置。1. Focusing the electron beam emitted from the electron beam generating means into a narrow one, scanning the sample with the beam, detecting particles generated from the sample, and displaying the sample image on a cathode ray tube based on the detection signal. In the device configured as above, means for detecting a DC component in the detection signal, means for detecting an amplitude value of an AC component in the detection signal, and selectively extracting the amplitude value of the DC component or AC component. A switch means is provided, and when the DC component is selected by the switch means, the amount of the electron beam irradiated onto the sample is controlled based on the difference between the DC component and the first reference signal, and the amplitude value of the AC component is controlled. An electron beam apparatus characterized in that when the amplitude value is selected, the amount of the electron beam irradiated onto the sample is controlled based on the difference between the amplitude value and the second reference signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56028108A JPS57143251A (en) | 1981-02-27 | 1981-02-27 | Electron beam apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56028108A JPS57143251A (en) | 1981-02-27 | 1981-02-27 | Electron beam apparatus |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57143251A JPS57143251A (en) | 1982-09-04 |
| JPS6257064B2 true JPS6257064B2 (en) | 1987-11-28 |
Family
ID=12239609
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56028108A Granted JPS57143251A (en) | 1981-02-27 | 1981-02-27 | Electron beam apparatus |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57143251A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6182645A (en) * | 1984-09-29 | 1986-04-26 | Jeol Ltd | X-ray microanalyzer |
-
1981
- 1981-02-27 JP JP56028108A patent/JPS57143251A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57143251A (en) | 1982-09-04 |
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