High-transconductance InGaAs/InAlAs SISFETs

SISFETs in the InGaAs/InAlAs lattice-matched-to-InP material system with record transconductance have been fabricated. These devices use an InGaAs channel layer grown on an InAlAs buffer layer grown on (and lattice matched to) a semi-insulating InP substrate. Carriers are induced in the undoped channel layer by the action of a doped InGaAs gate layer acting across an undoped InAlAs insulating layer. The device is thus the analog of the GaAs/AlGaAs SISFET (or more broadly the silicon gate MOSFET) but provides the electron transport advantages of InGaAs. In addition, ion implantation and arsine overpressure rapid thermal annealing of shallow implants into InGaAs were studied, and it was found that shallow self-aligning implantation structures can be achieved with much lower resistance than in GaAs.