Monolithic HEMT-HBT integration for novel microwave circuit applications

We have successfully achieved monolithic integration of HEMT and HBT devices in the same microwave circuit for the first time. We have used selective molecular beam epitaxy and a newly developed merged-processing technology to produce novel microwave integrated circuits that incorporate both pseudomorphic InGaAs-GaAs HEMTs and GaAs-AlGaAs HBTs on the same chip. The HEMT devices use 0.2 /spl mu/m gates, while the HBT devices use 2 and 3 /spl mu/m emitters. The performance of the merged HEMT and HBT devices is equivalent to that of baseline devices fabricated by our normal single-technology process. The HEMT devices achieve g/sub m/=600 mS/mm, while 3/spl times/10 /spl mu/m/sup 2/ HBTs achieve /spl beta//spl sim/50 at I/sub c/=1 mA. A monolithic HEMT-HBT integrated circuit is presented that uses active HBT regulation of a HEMT low-noise amplifier. The noise and gain performance of the monolithic HBT regulated 5-10 GHz HEMT LNA is shown to be equivalent to that of the same amplifier fabricated using our baseline HEMT-only process.