SiGe SOI p-MOSFET在高频、高速、低功耗、抗辐射方面具有极大的优势。但二氧化硅埋层较低的热导率以及SiGe材料较低的热稳定性,使器件内部自加热效应的减弱或消除成为提高器件温度特性的关键因素。对应变SiGe SOI p-MOSFET温度特性机理进行研究,给出了三种缓解MOS-FET器件内部自加热效应的结构,并对其效果进行对比分析。结果表明:DSOI结构不适宜于低压全耗尽型SOI器件;Si3N4-DSOI结构对自加热的改善幅度较小;Si3N4埋层结构效果最好,尤其在低温领域改善更为明显。
This paper proposes a novel super junction(SJ) SiGe switching power diode which has a columnar structure of alternating p and n doped pillar substituting conventional n base region and has far thinner strained SiGe p+ layer to overcome the drawbacks of existing Si switching power diode.The SJ SiGe diode can achieve low specific on-resistance,high breakdown voltages and fast switching speed.The results indicate that the forward voltage drop of SJ SiGe diode is much lower than that of conventional Si power diode when the operating current densities do not exceed 1000 A/cm2,which is very good for getting lower operating loss.The forward voltage drop of the Si diode is 0.66 V whereas that of the SJ SiGe diode is only 0.52 V at operating current density of 10 A/cm2.The breakdown voltages are 203 V for the former and 235 V for the latter.Compared with the conventional Si power diode,the reverse recovery time of SJ SiGe diode with 20 per cent Ge content is shortened by above a half and the peak reverse current is reduced by over 15%.The SJ SiGe diode can remarkably improve the characteristics of power diode by combining the merits of both SJ structure and SiGe material.
