A novel structure of ideal ohmic contact p^＋ （SiGeC）-n^- -n^＋ diodes with three-step graded doping concentration in the base region is presented, and the changing doping concentration gradient is also optimized. U...A novel structure of ideal ohmic contact p^＋ （SiGeC）-n^- -n^＋ diodes with three-step graded doping concentration in the base region is presented, and the changing doping concentration gradient is also optimized. Using MEDICI, the physical parameter models applicable for SiGeC/Si heterojunction power diodes are given. The simulation results indicate that the diodes with graded doping concentration in the base region not only have the merit of fast and soft reverse recovery but also double reverse blocking voltage,and their forward conducting voltage has dropped to some extent,compared to the diodes with constant doping concentration in the base region. The new structure achieves a good trade-off in Qs-Vf-Ir ,and its combination of properties is superior to ideal ohmic contact diodes and conventional diodes.展开更多
建立了超薄基区Si Ge和Si GeC HBT的速度过冲模型。通过求解能量平衡方程,得到电子温度分布,B-C结附近的电子温度远高于晶格温度。Ge的分布对Si Ge BHT速度分布影响很大,对于线性分布,Ge梯度越大,速度过冲越明显;Ge梯度一样时,线性分布...建立了超薄基区Si Ge和Si GeC HBT的速度过冲模型。通过求解能量平衡方程,得到电子温度分布,B-C结附近的电子温度远高于晶格温度。Ge的分布对Si Ge BHT速度分布影响很大,对于线性分布,Ge梯度越大,速度过冲越明显;Ge梯度一样时,线性分布比梯形分布的速度大。梯形分布的Si Ge HBT基区也发生速度过冲。Si GeC HBT速度过冲现象与Si Ge HBT相似。展开更多
This paper analyses the reverse recovery characteristics and mechanism of SiGeC p-i-n diodes. Based on the integrated systems engineering （ISE） data, the critical physical models of SiGeC diodes are proposed. Based ...This paper analyses the reverse recovery characteristics and mechanism of SiGeC p-i-n diodes. Based on the integrated systems engineering （ISE） data, the critical physical models of SiGeC diodes are proposed. Based on heterojunction band gap engineering, the softness factor increases over six times, reverse recovery time is over 30% short and there is a 20% decrease in peak reverse recovery current for SiGeC diodes with 20% of germanium and 0.5% of carbon, compared to Si diodes. Those advantages of SiGeC p-i-n diodes are more obvious at high temperature. Compared to lifetime control, SiCeC technique is more suitable for improving diode properties and the tradeoff between reverse recovery time and forward voltage drop can be easily achieved in SiGeC diodes. Furthermore, the high thermal-stability of SiGeC diodes reduces the costs of further process steps and offers more freedoms to device design.展开更多
文摘A novel structure of ideal ohmic contact p^＋ （SiGeC）-n^- -n^＋ diodes with three-step graded doping concentration in the base region is presented, and the changing doping concentration gradient is also optimized. Using MEDICI, the physical parameter models applicable for SiGeC/Si heterojunction power diodes are given. The simulation results indicate that the diodes with graded doping concentration in the base region not only have the merit of fast and soft reverse recovery but also double reverse blocking voltage,and their forward conducting voltage has dropped to some extent,compared to the diodes with constant doping concentration in the base region. The new structure achieves a good trade-off in Qs-Vf-Ir ,and its combination of properties is superior to ideal ohmic contact diodes and conventional diodes.
文摘建立了超薄基区Si Ge和Si GeC HBT的速度过冲模型。通过求解能量平衡方程,得到电子温度分布,B-C结附近的电子温度远高于晶格温度。Ge的分布对Si Ge BHT速度分布影响很大,对于线性分布,Ge梯度越大,速度过冲越明显;Ge梯度一样时,线性分布比梯形分布的速度大。梯形分布的Si Ge HBT基区也发生速度过冲。Si GeC HBT速度过冲现象与Si Ge HBT相似。
基金Project supported by the National Natural Science Foundation of China (Grant No 50477012)the Foundation of Excellent Doctoral Dissertation of Xi’an University of Technology and the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No 20050700006)
文摘This paper analyses the reverse recovery characteristics and mechanism of SiGeC p-i-n diodes. Based on the integrated systems engineering （ISE） data, the critical physical models of SiGeC diodes are proposed. Based on heterojunction band gap engineering, the softness factor increases over six times, reverse recovery time is over 30% short and there is a 20% decrease in peak reverse recovery current for SiGeC diodes with 20% of germanium and 0.5% of carbon, compared to Si diodes. Those advantages of SiGeC p-i-n diodes are more obvious at high temperature. Compared to lifetime control, SiCeC technique is more suitable for improving diode properties and the tradeoff between reverse recovery time and forward voltage drop can be easily achieved in SiGeC diodes. Furthermore, the high thermal-stability of SiGeC diodes reduces the costs of further process steps and offers more freedoms to device design.
