Published online by Cambridge University Press: 25 February 2011
The characteristics of GaAs MESFETs in GaAs-on-Si have been studied in detail for digital IC applications. The device structure utilizes GaAs and AlGaAs undoped buffer layers grown on a 3 degrees off (100) silicon substrate by MBE. The threshold voltage of the MESFET is adjusted by recessing the gate.
The maximum observed transconductance of 135 mS/mm is comparable to what is expected from the bulk GaAs device with the same parameters. The device also shows good pinch-off characteristics. Both enhancement and depletion mode MESFETs have been fabricated.