双面阶梯埋氧层部分SOI高压器件新结构

A new partial SOI high voltage device with double-faced step buried oxide structure

提出了双面阶梯埋氧层部分绝缘硅(silicon oninsulator,SIO)高压器件新结构.双面阶梯埋氧层的附加电场对表面电场的调制作用使表面电场达到近似理想的均匀分布,耗尽层通过源极下硅窗口进一步向硅衬底扩展,使埋氧层中纵向电场高达常规SOI结构的两倍,且缓解了常规SOI结构的自热效应.建立了漂移区电场的二维解析模型,获得了器件结构参数间的优化关系.结果表明,在导通电阻相近的情况下,双面阶梯埋氧层部分SOI结构击穿电压较常规SOI器件提高58%,温度降低10—30 K.

A novel PSOI （partial silicon-on-insulator） high voltage device with double-faced step buried oxide is proposed, which is called DSB PSOI（ PSOI with double-faced step burled-oxide layer）. The surface electric field has ideally uniform distribution due to the additive electric field modulation by double step buried oxide. A silicon window underneath the source helps to reduce selfbeating. The depletion region spreads into the substrate and the vertical electric field in the buried layer is enhanced, which results in a higher breakdown voltage than that of conventional SOI device. A 2-D quantified optimal relation between the structure parameters is also obtained. The results indicate that the breakdown voltage of DSB PSOI is increased by 58% in comparison with conventional SOI, while maintaining the low on-resistance of the DSB PSOI device.