超薄层SOI高压LVD LDMOS耐压模型及特性研究

Investigation on Breakdown Model and Characteristics for Ultra-Thin Layer High Voltage SOI LVD LDMOS

针对超薄层高压SOI线性变掺杂(Linear Varied Doping,LVD)LDMOS器件,进行了耐压模型和特性的研究。通过解泊松方程,得到超薄高压SOI LVD LDMOS的RESURF判据,有助于器件耐压和比导通电阻的设计与优化。通过对漂移区长度、厚度和剂量,以及n型缓冲层仿真优化,使器件耐压与比导通电阻的矛盾关系得到良好的改善。实验表明,超薄层高压SOI LVD LDMOS的耐压达到644V,比导通电阻为24.1Ω·mm2,击穿时埋氧层电场超过200V/cm。

Breakdown model and characteristics for ultra-thin SOI high voltage LVD LDMOS were investigated. RESURF condition for ultra-thin SOl high voltage LVD LDMOS was given with solving the Possion＇s equation, which contributed to the design and optimization of breakdown voltage （BV） and specific on-resistance （Ron,sp）. Through simulated optimization for the length, thickness, dose of drift region and N-buffer, the relationship between BV andRon.sp were improved. The experimental results showed that BV of 644 V andRon,sp of 24.1 Ω·mm2 were achieved with the electric field in BOX layer beyond 200 V/cm.