绝缘电介质薄膜中空间电荷分布测量技术的研究进展  

Progress in Research on Space Charge Distribution Measurements in Solid Dielectric Thin Films

作　　者：郑飞虎[1] 张冶文[1] ZHENG Feihu;ZHANG Yewen(Department of Electrical Engineering,Tongji University,Shanghai 201804,China)

机构地区：[1]同济大学电气工程系,上海201804

出　　处：《高电压技术》2020年第7期2460-2470,共11页High Voltage Engineering

基　　金：国家自然科学基金(51477119)。

摘　　要：绝缘电介质薄膜广泛用作为高压电气设备中的绝缘材料和传感器件中电介质功能材料,如果用在直流高压应用条件下,空间电荷分布是其重要的特性表征。如果用于功能电介质,空间电荷分布是其功能实现的决定性因素之一。为此总结了厚度为数微米至几十微米的薄膜电介质中空间电荷分布测量方法的研究进展,按照测量的空间分辨率分别介绍了压力波法、热扰动法、电声反射法和基于飞秒脉冲激光器光电测量方法的测量原理。比较了这几种测量方法的特点,讨论了影响测量分辨率的几个关键因素:如对介质的扰动方式、对介质响应信号的探测方式以及对响应信号处理的解卷积方法。压力波法和热扰动法是其中较为成熟有效的测量方法,分辨率介于亚微米及数微米之间,扰动方法及信号监测都相对容易实现,而热扰动法虽然较容易实现亚微米分辨率,但数据处理较为繁琐。目前还处于试探阶段的电声反射法的测量基于网络分析仪,具微米级空间分辨率。基于飞秒脉冲激光器光电测量法是对传统压力波法或电声脉冲法的改进,通过太赫兹窄脉冲扰动,利用光电方式实现极高带宽测量,能够实现数十纳米级空间分辨率。Dielectrics films are widely used as insulating materials and functional materials,and the distribution of space charge is their important feature parameters under high voltage application.As functional dielectric films,the space charge distribution can affect the external characteristics of the functional devices.In this paper,we summarize the research progress of non-destructive measurement of space charge distribution in dielectrics films with the thickness of several nanometers to dozens of micrometers.According to the achieving spatial resolution of the measuring technologies,we introduce,respectively,the measurement methods including pressure wave propagation method,thermal perturbation method,electro-acoustic reflection method,femtosecond pulse laser based high space resolution measurements,and the related data processing algorithms.The characteristics of these measurement methods are compared,and several key factors affecting the measurement resolution are discussed as follows:the disturbance mode to the dielectrics films,the detection mode to the dielectric response signal,and the deconvolution method for the response signal processing.Pressure wave method and thermal disturbance method are relative mature and effective measurement method,of which their resolutions are between sub-micron and several microns.The disturbance and the response signal monitoring are relatively easy to achieve.The thermal disturbance method is easier to achieve sub-micron resolution,but the data processing is more tedious.The measurement of electro-acoustic reflection method is based on network analyzer and has micrometer spatial resolution.The photoelectric measurement method based on femtosecond pulse laser disturbance is considered to be an improvement of the traditional pressure wave method or pulsed electro-acoustic method.The ultra-high bandwidth measurement is realized by means of THz pulse disturbance,and the spatial resolution of tens of nanometers has been achieved.

关 键 词：薄膜电介质 空间电荷分布 空间分辨率 压力波法 热扰动法 电声反射法 光电测量法 

分 类 号：TM933.23[电气工程—电力电子与电力传动]