Monolithic integration of AlGaAs/GaAs HBT and GaAs junction-gate floated electron channel field effect transistor using selective MOCVD growth

Abstract

A novel GaAs BiFET structure based on AlGaAs/GaAs HBT and GaAs junction-gate floated electron channel field effect transistor (J-FECFET) has been developed, Selective metalorganic chemical vapor deposition (MOCVD) growth is extensively used for the BiFET, Structural advantage of the BiFET is that the epitaxial layers of J-FECFET is identical with the lower part of a conventional heterojunction bipolar tranistor (HBT), Transconductance of the fabricated J-FECFET with 1 x 200 mu m(2) gate is 102 mS/mm with f(T) and f(MAX) of 10.7 GHz and 27.3 GHz, respectively. DC current gain of HBT is 21 at a collector current density of 50 KA/cm(2) with emitter area of 3 x 2 mu m(2). The new integration technology offer a foundation for development of various multifunction monolithic microwave integrated circuits (MMIC's).