扫描探针显微镜针尖电容的测量与应用  

Application of measuring the capacitance of the tip in SPM

作　　者：孙浩明[1] 王志红[1] 曾慧中[1] 古曦[1] 

机构地区：[1]电子科技大学电子薄膜与集成器件国家重点实验室,成都610054

出　　处：《电子测量技术》2009年第2期163-165,169,共4页Electronic Measurement Technology

摘　　要：本文基于扫描探针显微镜(SPM)建立了微区电容的低频测量系统,最小测量电容为30aF,工作频率为20～100kHz。试验测量了SPM导电针尖与金属样品之间的电容Ctip与它们之间的距离z关系曲线,并同时通过光学系统测量了针尖的关于频率的一次受力信号Fw与z的关系曲线。推导了两种测量方法所获曲线的内在关系,并获得了针尖与样品的表面势之差。并且,利用此系统测量了Al0.3Ga0.7N/GaN薄膜的微区C-V曲线,获得和宏观C-V曲线趋势一致的结果。It＇s present in the paper that a system measuring micro-area capacitance with a low frequency method is established on the scanning probe microscopy（SPM）. The smallest capacitance measured is 30 aF, and the system can work between 20 to 100 kHz. A curve of the capacitance Ctip between the AFM tip and metal depending on their distance z is measured, and at the same time, so do with a curve of the first-order force single Fw of frequency depending on z. We confirm the relationship of the two curves with different method after a comparison, and calculate out the difference of the surface potential between the tip and sample. At the last, we get the micro-area C-V curve of Al0.3Ga0.7N/GaN thin film. It has the same trend with the macroscopic C-V curve.

关 键 词：扫描探针显微镜 微区电容 锁相放大 C-z曲线 C-V曲线 

分 类 号：TN16[电子电信—物理电子学]