Fabrication of microwave devices on ultrathin active GaAs substrates

A fabrication process for a microstrip structure on a 5 micron thick n-doped GaAs active substrate was designed. The resulting distributed Gunn diode is intended to be used as a voltage controlled oscillator. The process includes molecular beam epitaxy growth of active layers, selective etching using a GaAlAs etchstop layer, and the formation of an integral heat sink. The process has 30 discrete steps and takes a week to produce a device. The technology could also be used in the fabrication of other high power devices such as power FET's.