非接触半绝缘SiC电阻率测试

半绝缘碳化硅单晶(SI-SiC)是非常具有吸引力的大功率电子器件衬底材料,目前已越来越多地引起了人们的重视。其晶片电阻率的测试一直是一个难题。介绍了一种非接触电阻率测试方法,可以有效地解决这一难题。该方法利用电容充放电原理。首先对样品进行瞬时充电,再利用仪器实时检测放电过程中的总电量,从而得到其变化的弛豫曲线,之后对该曲线进行数学分析得到弛豫时间τ,最后利用弛豫时间τ计算出半绝缘碳化硅单晶的电阻率。实际测试时,先将晶片表面划分为若干等面积的小区域,再利用仪器逐个测试这些区域的电阻率,最后将所有电阻率的数据处理成一张电阻率分布图。该方法对半绝缘材料的研究工作具有积极的指导作用。

Non-Contact Method for Measuring Resistivity of SI-SiC

The monocrystal of semi-insulating SiC(SI-SiC)is a kind of very attractive substrate material for high power electronic apparatus,it is paid much attention by more and Inore people.But it is very hard to test the resistivity of SI-SiC.A kind of SI-SiC non-contact resistivity test method is introduced,which can solve this problem effectively.In this method,according to the principle of charge and discharge in capacitance,the samples were charged instantaneously,at the same time,in real-time test,the total discharge were measured by instrument automatically.According to the changing curve,relax time τ was got by mathematics analysis,and the resistivity of SI-SiC was obtained with the parameter τ.In the real-time test.firstly the chip surface area was divided into a number of small areas,then the resistivity of these areas was measured one by one,finally,all the resistivity data were processed into a resistivity distribution map.This test method also has a positive effect to the research of sbmi-insulating material.