一种新型的SOI MOSFET衬底模型提取方法

A New Substrate Model Extraction Method for RF SOI MOSFET

衬底寄生网络建模和参数提取,对RF SOI MOSFET器件输出特性的模拟有着非常重要的影响。考虑BOX层引入的体区和Si衬底隔离,将源、体和衬底短接接地,测试栅、漏二端口S参数的传统测试结构,无法准确区分衬底网络影响。提出一种改进的测试结构,通过把SOI MOSFET的漏和源短接为信号输出端、栅为信号输入端,测试栅、漏/源短接二端口S参数的方法,把衬底寄生在二端口S参数中直接体现出来,并开发出一种解析提取衬底网络模型参数的方法,支持SOI MOSFET衬底网络模型的精确建立。采用该方法对一组不同栅指数目的SOI MOSFET进行建模,测量和模型仿真所得S参数在20 GHz频段范围内得到很好吻合。

Substrate parasitic network modeling and parameter extraction have significant influence on the modeling of output characteristics for RF SOI MOSFET devices. The isolation between the introducing bulk region of the BOX layer and the Si substrate is considered. The traditional common-source structure that connecting source , body and substrate together to ground couldn ＆#39;＆#39;t distinguish the substrate parasitic network with the active region. An improved test structure was proved to extract the substrate parasitic parameters by connecting the drain and source as output port and gate as input port. An accurate substrate modeling method based on different fingers was developed to build SOI MOSFETs models. The simulating S parameter matched the measured result quite well under 20 GHz.