Growth and Evaluation of Epitaxial GaAs for Microwave Devices

Abstract

Using liquid phase epitaxy (LPE), single, double, and triple epitaxial layers are grown. The layers have well‐controlled, uniform thicknesses and good surface characteristics on wafers 1½ in. long. Individual layers in multilayer structures are grown with thicknesses from 0.3 to 30 μm. Hall mobilities at 77°K vary from 73,800 cm2 V−1 sec−1 . A segregation coefficient for the net carrier concentration vs. Sn concentration in the melt is calculated as and substrates. Gunn devices fabricated from this material using conventional flip chip design give up to 4% cw efficiency at 54 GHz, gradually increasing to 12.5% cw efficiency at 9–10 GHz. This technique has also been successfully used to grow epitaxial layers for varactors, avalanche diodes, FET devices, and photocathodes.