The use of GaAs—(Ga, Al)As heterostructures for FET devices

The metalorganic VPE process has been applied to the growth of GaAs-GaAlAs heterostructures suitable for FET devices. Two kinds of materials are examined; namely, insulating GaAlAs hetero-buffer and heterojunction p-GaAlAs-n-GaAs, The technology of device processing uses selective etching and self-alignment techniques. The heterobuffered FET's demonstrate effective electron confinement and the heterojunction HJFET's exhibit a built-in voltage of 1.4 eV. However, more has to be known on the transition at the heterointerface to improve the device performances.