中文摘要：

在考虑到各种物理机制如载流子-载流子散射、俄歇复合、禁带窄化效应及结温效应等的基础上，数值模拟分析了SiGe／Si功率开关二极管的各种温度依赖特性。对Si和SiGe／Si功率二极管而言，温度对器件的正向压降Vr、反向击穿电压Ve以及反向漏电流JR的影响规律基本相似，即随着温度的升高，正向压降降低，击穿电压增加，反向漏电流迅速提高。然而在相同的温度下，与Si功率开关二极管相比，SiGe／Si二极管（20％Ge含量）的正向压降降低了近0．1V（在正向电流密度10A／cm^2的情况下），反向恢复时间缩短了一半以上，反向峰值电流密度也下降了约三分之一，软度因子S提高了2倍多。SiGe二极管的另外一个重要优点是其反向恢复特性受温度影响很小。当温度从300K增加到400K时，Si功率二极管的反向恢复时间增加了近1倍，而SiGe／Si二极管（20％Ge含量）的反向恢复时间基本保持不变。SiGe／Si功率开关二极管的一个缺点是在高温下产生较大的漏电流，但这可以通过适当降低Ge含量来改善。Ge的引入为器件设计提供了更大的自由度，其含量对器件特性有重要影响。为了获得低的正向压降和短的反向恢复时间，应该提高Ge的含量，但Ge含量增加将导致大的漏电流，因此Ge含量的大小应该优化折衷考虑。

英文摘要：

Numerical simulation and analysis on temperature-dependent charaeteristicg of SiGe/Si power switching diodes has been done, incorporating various physical mechanisms such as carrier-carrier scattering, Auger recombination, bandgap narrowing and the junction tempera ture effect et al. The temperature-dependent physical models applicable for SiGe/Si diodes are al so presented. For both SiGe/Si and Si diodes, the temperature effects on the forward voltage drop VF, reverse breakdown voltage VB and reverse current density JR are essentially similar, that iS,VF decreases linearly, Vu increases linearly and JR increases rapidly with the increasing temperature. However, compared with Si diode at the same temperature, the forward voltage drop decreases nearly 0. 1 V at the current density of 10 A/cm^2, the reverse recovery time is shortened above a half, the peak reverse recovery current decreases by one third, and the softness factor S increases over 2 times for the SiGe/Si diode （20% Ge content）. Another important ad- vantage of SiGe/Si diodes is that the reverse recovery characteristics are weakly dependent on the temperature. When temperature increases from 300 K to 400 K, the reverse recovery time increa- ses nearly one time for Si diode whereas it almost keeps a constant value for SiGe/Si diode （20% Ge content）. A drawback of SiGe/Si diodes is large reverse leakage current at high temperature, but the defect could be improved by lowering the Ge content. Ge content is an important parame- ter to affect the characteristics of SiGe/Si diodes, which offers more freedom to device design. To obtain lower forward voltage drop and faster reverse recovery time, the SiGe/Si diodes with high Ge content should be used. However, high Ge content will give rise to large leakage current. Therefore, a trade-off between forward voltage drop, reverse recovery time and leakage current by the Ge content should be considered.