斜埋氧SOI LDMOS高压器件新结构  

Novel High Voltage SOI LDMOS with a Slope Buried Oxide Layer

作　　者：阳小明[1] 李天倩[1] 王军[1] 卿朝进[1] 

机构地区：[1]西华大学电气信息学院,成都610039

出　　处：《半导体技术》2013年第1期16-19,50,共5页Semiconductor Technology

基　　金：教育部春晖计划(Z2011091);四川省教育厅重点项目(12ZA161);四川省重点学科资助项目(SZD0503-09-0)

摘　　要：为了提高基于绝缘体上的硅(SOI)技术实现的横向扩散金属氧化物半导体器件(SOI LDMOS)的击穿电压,提出了斜埋氧SOI LDMOS(S SOI LDMOS)耐压新结构。当器件关断时,倾斜的埋氧层束缚了大量的空穴,在埋氧层上界面引入了高密度的正电荷,大大增强了埋氧层中的电场,从而提高了纵向耐压。另外,埋氧层的倾斜使器件漂移区厚度从源到漏线性增加,这就等效于漂移区采用了线性变掺杂,通过优化埋氧层倾斜度,可获得一个理想的表面电场分布,提高了器件的横向耐压。对器件耐压机理进行了理论分析与数值仿真,结果表明新结构在埋氧层厚度为1μm、漂移区长度为40μm时,即可获得600 V以上的击穿电压,其耐压比常规结构提高了3倍多。In order to improve the breakdown voltage, a novel silicon-on-insulator （SOI） laterally diffused metal oxide semiconductor （LDMOS） with a slope buried oxide layer was proposed. In off-state, many holes were astricted by the buried oxide layer. The high density accumulated positive charge layer can significantly enhance the electrical field in the buried oxide and greatly increase the vertical breakdown voltage. The main mechanism of the slope buried oxide layer for increasing the lateral breakdown voltage （VR） was similar to the variation of lateral doping. The surface electric field was modulated by the drift region of the new structure. And then, the lateral breakdown voltage was improved too. The mechanism of breakdown voltage was analyzed and simulated. The simulation results show that the breakdown voltage is above 600 V in the new structure with 1 μm thick buried oxide layer and 40 μm long drift region. The breakdown voltage of S SOI LDMOS is four times as high as that of the conventional SOI LDMOS.

关 键 词：空穴 斜埋氧层 绝缘体上的硅 临界击穿电场 击穿电压 

分 类 号：TN386[电子电信—物理电子学]