JSA Vol.11 No.2 Pages 71-76
AES分析装置を用いた二次電子放出係数測定
荒木 祥和株式会社日産アーク 〒237-0061 神奈川県横須賀市夏島町1番地(2004年2月27日受理；2004年4月26日掲載決定)
Abstract
二次電子放出現象は，表面付近で起こるため，二次電子放出係数δ（二次電子の数／一次電子の数）は表面組成に大きく依存する．本報告では，この測定のために製作した特製ファラデーカップ付きサンプルホルダーと既存のAES分析装置を用いて，組成を把握した上でδを測定する手法を検討した．このサンプルホルダーの特長は，試料近傍に試料と絶縁が保たれた状態で正バイアスを印加できる構造である．一次電流値は25pAに設定した．このバイアス機構と微弱な一次電流によって，導電性の悪い試料で起こる，二次電子の表面への引き戻し現象を抑止する効果があると考えられる．
本手法により様々な試料におけるδの一次電子エネルギー依存性を測定した．δの最大値：δmとその時の一次電子エネルギー：Emについて文献値との比較を行った結果，本測定で得られた値は，文献値と比較的よい一致を示した．
Secondary Electron Emission Coefficient Measurement Technique with Scanning Auger Microprobe
Sawa ARAKI
NISSAN ARC, LTD.1, Natsushima, Yokosuka 237-0061(Received: February 27, 2004; Accepted: April 26, 2004)
Abstract
The behavior of secondary electron emission on various surfaces has been studied in detail using a conventional scanning Auger microscope (SAM). In order to understand the possible effect of surface composition on secondary emission, we have examined both the surface composition and the behavior of secondary emission coefficient d using a SAM and a specially designed sample holder with a Faraday-cup attachment. It is shown that secondary electron emission coefficient d, defined as the number of secondary electrons divided by number of primary electrons, is significantly dependent upon the surface composition. The special design of the sample holder allows us to apply positive voltages to the surrounding sample, keeping it insulated from the sample. The primary electric current was 25pA. This bias application and the very weak primary electric current value might suppress the secondary electrons to return to the surface, which is often experienced in non-conductive materials.
We have measured d of various samples as a function of the primary electron energy. The observed values, the maximum secondary emission coefficients dm and the primary electron energies Em for maximum emission, have been compared with the reference data, and it was found a fairly good agreement.
