SOI-LDMOS器件改善电安全工作区后驼峰现象的研究

研究了高压SOI-LDMOS器件在引入P-sink结构改善电安全工作区(E-SOA)后I-V特性曲线呈现的驼峰现象(hump)。首先将驼峰现象出现后器件的源端总电流分成电子电流与空穴电流单独分析,确定高栅压下电子电流阶梯上升是驼峰现象产生的表面原因,进而通过仿真分析出Kirk效应导致的空穴电流在表面漂移区中电导调制是驼峰现象产生的根本原因。最后,根据对驼峰现象的分析,设计出新器件结构成功消除了驼峰现象,为今后不同类型LDMOS器件改善I-V曲线驼峰现象提供了理论指导。

The Research on Hump Phenomenon after Improving Electrical Safe Operating Area of SOI-LDMOS

The hump phenomenon of I-V characteristic after introducing P-sink structure to improve electrical safe operating area(E-SOA) on the high voltage SOI-LDMOS has been investigated in this paper.Firstly,the electron current and hole current are extracted and analyzed from total current at source side separately to make sure that the electron current step increase is the appearance reason for hump phenomenon,and then hole conductivity modulation in surface N-drift region induced by Kirk effect at drain side is confirmed as the deep reason.Moreover,according to the analysis in this paper,a new SOI-LDMOS structure has been designed to eliminating hump phenomenon,which gives the theoretic instructions for eliminating hump phenomenon of high voltage LDMOS more accurately.