摘要
提出具有屏蔽槽的SOI高压器件新结构和自适应界面电荷耐压模型.该结构在屏蔽槽内产生跟随漏极电压变化的界面电荷,此电荷使埋层介质的纵向电场增加,同时使顶层硅的纵向电场降低,并对表面电场进行调制,因此屏蔽了高电场对顶层硅的影响.借助二维器件仿真研究器件耐压和电场分布与结构参数的关系.结果表明,该结构使埋氧层的电场从传统的3ESi升高到近600V/μm,突破了传统SOI器件埋氧层的耐压值,大大提高了SOI器件的击穿电压.
A novel SOI high voltage device structure with a shielding trench and its breakdown mode with a self-adapted interface charge are proposed. Interface charges that change with the drain voltage are introduced in the shielding trench. Interface charges enhance the vertical electric field of the buried layer and reduce that of the top Si layer simultaneously. Furthermore, they also modulate the surface electric field. So,interface charges shield the top Si layer from a high electric field. The breakdown voltage and electric field profile are researched for different device parameters for a ST structure by using a 2D device simulator. It is shown that the electric field of buried oxide increases from about 3Esi to 600V/μm. It breaks through the limitation of the sustained voltage of the buried oxide layer of a normal SOI device and enhances the breakdown voltage of the SOI device remarkably.
基金
国家自然科学基金资助项目(批准号:60436030)~~
关键词
屏蔽槽
自适应界面电荷
调制
纵向电场
击穿电压
shielding trench
self-adapted interface charge
modulate
vertical electric field
breakdown voltage
