High performance InGaP/GaAs HBTs with AlGaAs/InGaP emitter passivated ledges for reliable power applications

High performance InGaP/GaAs HBTs have been demonstrated with novel AlGaAs/InGaP emitter passivated ledges on the extrinsic base region to achieve good device reliability. Using this technology, our X-band HBTs fabricated have been under stress test for /spl sim/2500 hours with an initial junction temperature of 200/spl deg/C and a J/sub c/ of 50 KA/cm/sup 2/ and there is only /spl sim/5% degradation observed with no early catastrophic failure. In terms of power performance, our X-band HBT power amplifiers achieved typical output power of 1.32 W CW (4.42 W/mm), 60% power added efficiency, 70.6% collector efficiency and 8.18 dB associated gain at 10 GHz.