Silicon Based Heterojunction Devices For Microwave Amplification and Generation

摘要

Si-based heterojunction such as Si/Si(1-x)Ge(x) offer a route to high speeddevices on silicon substrates. F(max)'s in excess of 150 GHz have been reported. In this report we describe the first measurements of the effect of carbon the bandgap in defect free Si/Si(1-x-y)Ge(x)C(y) films. The bandgap was measured by both transport and photoluminescence experiments. Adding carbon to compressively strained SiGeC films grown pseudormorphically on Si(100) was found to increase the bandgap by 21-26 meV/%C. This is far less than would occur by decreasing strain by just reducing the Ge content, and shows SiGeC can substantially expand the range of applications of Si-based heterostructures.