An AlGaAs/InGaAs HEMT Grown on Si Substrate with Ge/GexSi1-x Metamorphic Buffer Layers

Abstract

An AlGaAs/InGaAs HEMT grown on Si substrate with Ge/GexSi1-x buffer is demonstrated. The Ge/GexSi1-x metamorphic buffer layer used in this structure was only 1.0 mu m thick. The electron mobility in the In0.18Ga0.82As channel of the HEMT sample was 3,550 cm(2)/Vs. After fabrication, the HEMT device demonstrated a saturation current of 150 mA/mm and a maximum transconductance of 155 mS/mm. The well behaved characteristics of the HEMT device on the Si substrate are believed to be due to the very thin buffer layer achieved and the lack of the antiphase boundaries (APBs) formation and Ge diffusion into the GaAs layers. Index Terms: HEW GaAs on Si, SiGe buffer layer