The Simulation And Analysis Of Two Kinds Of Novel Structure Of SiGe/Si Fast Switching Power Diode

As a branch of the study of SiGe/Si hetero- junction material system, SiGe PiN diode (p'(SiGe)-n'-n') is paid more and more attention to. SiGe diode ameliorates Si PiN performance and is compatible with Si process. For the material characteristics limitation of Si, the switching power loss of Si PiN diode increase with the switching frequency so that it is necessary to reduce the switching power loss by lifetime control technology which employs lifetime killer such as Au, Pt or radiation to lower the stored charge(Q.,). Unfortunately, though the lifetime control technology reduces the stored charge, it increases the forward voltage drop(Vr) and the reverse leakage current (I,). Therefore, Si PiN diode cannot realize a good trade-off in Qs-Vf-I,-. The appearance of SiGe material and SiGe/Si hetero-junction technology has changed this situation.On the base of the study on Si/SiGe hetero-junction fast switching power diode, two kinds of novel structure of SiGe/Si PiN diode are proposed inAbstractthis paper. The one is the gradual changing doping concentration in the n -region, and the other is SiGe PiN diode with mesa structure. After simulating the reverse recovery voltage and current characteristics, the forward and backward I-V characteristics and temperature characteristics with MEDICI, the optimal design to some key parameters is proposed. The researching results indicate that using the two kinds of novel structure, the fast-switching and the soft recovery characteristics of the device are much improved but not notable changed in forward drop, and the temperature characteristic is improved, too. Most of the characteristics are far better than the normal PiN diode structures. This paper is good for p'(SiGe)-n -n' hetero-junction diode in numerical value simulation, design and research and development.