Direct imaging of charge redistribution in a thin layer

¹ Samsung Electronics Co. Ltd. - Yongin, Kyunggido 449-900, Korea
² National Creative Research Initiative, Center for Sciences in Nanometer Scale, ISRC and Department of Physics, Seoul National University - Seoul 151-742, Korea
³ PSIA Corp. - Sungnam, Kyunggido 462-120, Korea
⁴ Department of Electrical Engineering, Myongji University Yongin, Kyunggido 449-728, Korea
⁵ Department of Physics Education, Seoul National University - Seoul 151-742, Korea
⁶ Department of Physics, Myongji University - Yongin, Kyunggido 449-728, Korea

Corresponding author: cjkang@mju.ac.kr

Received: 28 July 2003
Accepted: 13 May 2004

Abstract

Charge redistribution dynamics after electrical stress in a thin oxide layer was observed by scanning capacitance microscope. Image contrast and local capacitance spectroscopy show the kind of trapped charges and their behavior in the oxide with time. After high negative-voltage stress on a local area, electrons trapped initially are detrapped away and rather slow positive mobile carriers are attracted by the trapped electrons. These carriers are spread away from each other by the repulsive interaction among them and finally form a donut-shaped structure with the inside of electron traps.