Impact ionisation and noise in SiGe multiquantumwell structures

Abstract
A modified Keldysh form is proposed for ionisation scattering rates in strained SiGe layers. These rates are incorporated into a hot-carrier calculation to study avalanche noise in SiGe MQW structures. It is found that carrier heating is controlled by the thick Si layers and a pulsing of the ionisation in the SiGe layers acts to reduce the excess noise.