陷阱效应对4H-SiC MESFET频率特性的影响  

The Influence of Trapping Effect on Frequency Characteristics in 4H-SiC MESFETs

作　　者：吕红亮[1] 张义门[1] 张玉明[1] 车勇[2] 王悦湖[1] 邵科[1] 

机构地区：[1]西安电子科技大学微电子学院教育部宽禁带半导体重点实验室,陕西西安710071 [2]武警工程学院军械运输系,陕西西安710086

出　　处：《电子学报》2008年第5期933-936,共4页Acta Electronica Sinica

基　　金：国家自然科学基金(No.60606022);国防973重点基础研究发展规划(No.51327010101)

摘　　要：针对4H-SiC射频MESFET中的陷阱效应,建立了基于解析模型的器件小信号参数模型,引入能够反映陷阱影响的参数Rds″、gm″、Css等,从而能够由此分析器件特性随频率偏移的情况.对沟道缓冲层界面深能级陷阱的分析表明,4H-SiC MESFET的跨导既有正向偏移,也有负向偏移.偏移频率在室温下不足1Hz,但在600K的温度下则可达到MHz的量级.结合自热效应模型,论文还分析了栅、漏极偏置和温度对器件频率偏移特性的影响.模拟结果表明,随着温度的上升,偏移频段上升.本文的模拟分析对器件的设计提供了理论上的依据.Based on the small signal equivalent circuit of SiC MESFETs, the trapping effect has been investigated in detail. The elements of Rds^n , gm^n and Css have been involved in and the Impping-emission mechanism is discussed in detail. Both positive and negative frequency dispersions of transconductance are simualted and analyzed with deep level Imps located at the channel/ buffer interface. The dispersion frequency is less than 1Hz at room temperature. However, with increasing temperature, the dispersion frequency increases can be of the order of MHz at 600K. By combining modeling techniques, material physics and self-heating effects, the influences of the applied voltage and self-heating effect are analyzed. The simuiation indicates that the dispersion frequency increases with elevated temperature. The proposed model is valuable for the analysis of frequency dispersion in the device.

关 键 词：碳化硅 MESFET 深能级陷阱 频率特性 

分 类 号：TN304.2[电子电信—物理电子学]