Comparison of electronic characteristics and thermal resistance for HEMTs grown on GaAs and Si substrates

HEMTs have been successfully fabricated on silicon and their thermal resistance evaluated for the first time. A maximum transconductance of 330 mS/mm was obtained with 0.8 mu m gate length and 105 mu m width. The thermal resistance of the HEMTs on Si was 36+or-5 degrees /W with total device thickness of 400 mu m, demonstrating that the thermal resistance of GaAs/Si is about half that of GaAs/GaAs.