New SiGe bipolar transistors and p-i-n diodes for power switching

We have first fabricated bipolar transistors and p-i-n diodes for power switching by using SiGe. Misfit dislocations with Ge addition in the film allow the reduction of minority carrier lifetime. If the Ge concentration in the SiGe layer is chosen in the range below 10% to avoid excessive misfit dislocations, the breakdown characteristics of the pn-junction at the SiGe/Si heterojunction are not deteriorated. When SiGe is used at the base layer in npn/sup -/n/sup +/ bipolar transistors, a fast switching time of /spl sim/20 ns is possible in the 280 V-20 A class transistors, while the low on-voltage drop of 0.34 V is achieved at a collector current density of 113 A/cm/sup 2/. Moreover, if SiGe is applied to the p-anode in the thin -p/n/sup -/n/sup +/ -diodes, the recovery time can be lowered more than 50% compared with Si diodes with the same structure.