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The effect of bias voltage on the measurement of local barrier height
Author(s) -
Yoshitake Michiko,
Yagyu Shinjiro
Publication year - 2004
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.1851
Subject(s) - constant (computer programming) , biasing , voltage , constant voltage , current (fluid) , constant current , chemistry , analytical chemistry (journal) , electrical engineering , thermodynamics , physics , chromatography , computer science , engineering , programming language
The effect of experimental conditions on local barrier height (LBH) measurement with the STM technique was examined based on Simmons' formula. It has been revealed that the effect of bias voltage on LBH has to be measured under constant tip–specimen separation, not under constant tunnel current as normally used, because tip–specimen separation varies with bias voltage under constant current condition. We propose to start LBH measurement with I – V curve measurement and vary bias voltage along the I – V curve so that the tip–specimen distance is kept constant. We also propose to use the I – V curve to choose an equation suitable for LBH calculation in a specific bias voltage. The formula applicable for each bias voltage has been given. Copyright © 2004 John Wiley & Sons, Ltd.