Impact ionization in strained-Si/SiGe heterostructures

We have experimentally studied impact ionization (II) in a strained-Si/SiGe heterostructure. We found that, unlike bulk Si, II in this heterostructure has a positive temperature coefficient. Coupled with the severe self-heating that characterizes this heterostructure, this results in significantly higher levels of II when compared with reference Si devices operating under identical conditions.