物理化学学报 >> 2009, Vol. 25 >> Issue (06): 1213-1218.doi: 10.3866/PKU.WHXB20090527

研究论文 上一篇    下一篇

双极性半导体钝化膜空间电荷电容分析(II)

陈长风, 姜瑞景, 钱进森, 郑树启   

  1. 中国石油大学(北京)机电学院材料科学与工程系, 北京 102249
  • 收稿日期:2008-12-18 修回日期:2009-02-02 发布日期:2009-06-05
  • 通讯作者: 陈长风 E-mail:Chen_c_f@163.com

Analysis of the Space Charge Capacitance of Bipolar Semiconductor Passive Films (II)

CHEN Chang-Feng, JIANG Rui-Jing, QIAN Jin-Sen, ZHENG Shu-Qi   

  1. Department of Materials Science and Engineering, China University of Petroleum (Beijing), Beijing 102249, P. R. China
  • Received:2008-12-18 Revised:2009-02-02 Published:2009-06-05
  • Contact: CHEN Chang-Feng E-mail:Chen_c_f@163.com

摘要:

将双极性半导体钝化膜空间电荷电容等效为钝化膜/溶液界面处电容和内层钝化膜/外层钝化膜界面处的np结电容的串联, 根据前期研究建立的半导体富集态、耗尽态以及反型态空间电荷电容的统一计算公式, 给出了双极性钝化膜Mott-Schottky(M-S)曲线的非线性拟合方法. 并将这一方法应用于镍基合金G3高温高压H2S/CO2腐蚀后的钝化膜半导体特征研究. M-S曲线非线性拟合结果显示, 温度升高外层p型半导体钝化膜多数载流子浓度明显增高, 而内层n型半导体钝化膜的多数载流子浓度基本未变. 通过非线性拟合, 证明本文所给出的M-S曲线非线性拟合方法能够同时给出钝化膜内外层多个半导体性质参数,为揭示钝化膜形成及破坏机制提供更多信息. 结合X射线光电子能谱(XPS)分析, 讨论了钝化膜结构变化机制及np结在抑制腐蚀过程中的作用.

关键词: 双极性, 钝化膜, Mott-Schottky曲线, 非线性拟合

Abstract:

In this paper, the space charge capacitance of a bipolar semiconductor passive filmwas considered to be equivalent to a series connection of a capacitance at the passive film/solution interface and an np-junction capacitance at the outer layer film/inner layer film interface. Based on a uniform expression established in our previous work, a non-linear method was used to fit the Mott-Schottky (M-S) plots of bipolar semiconductor passive films. We then investigated the semiconductor characteristics of passive films formed on the surface of the nickel base alloy G3 after environmental corrosion at high temperatures and high partial pressures of H2S/CO2 using this method. Fitting results of measured M-S plots indicated that the majority carrier density of the p type semiconductor outer layer of the bipolar passive film obviously increased as the temperature increased while the majority carrier density of the n type semiconductor inner layer was almost unchanged. The fitting results show that the non-linear fitting method can produce multiple semiconductor characteristic parameters of the inner/outer layer of bipolar passive films. From these fitting results a mechanism for the formation and breakdown of passive films was established. A variable mechanism for the passive film structure and the role of the np-junction in the corrosion inhibition process were discussed by considering X-ray photoelectron spectroscopy (XPS) results as well.

Key words: Bipolar, Passive film, Mott-Schottky plot, Non-linear fitting

MSC2000: 

  • O649