GaAs/AlGaAs inversion channel devices for an integrated opto-electronic technology

Optoelectronic integrated circuits based on devices having an inversion channel (electrons) induced at a heterointerface by a charge sheet of donors placed at the heterointerface have been investigated. These devices include the HFET, a heterojunction analog to the MOSFET; the HFED, a three-terminal lateral photodetector; the BICFET, a bipolar transistor in which the inversion channel acts as an induced base to eliminate charge storage; and the DOES, a three- or four-terminal optical/electrical switching device. The intrinsic compatibility of these devices was demonstrated by fabricating a single device structure on a GaAs/AlGaAs MBE (molecular-beam epitaxy)-grown wafer. Devices were processed using a mesa technology with refractory gates, self-aligned ion implantation and high-temperature RTA (rapid thermal annealing) cycles. The measured characteristics of the devices, obtained without optimization of the material growth, the device structural design, or the fabrication, indicate that the inversion channel technology has a unique potential for optoelectronic integration.<
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