High linearity, current drivability and f/sub max/ using pseudomorphic GaAs double-heterojunction HEMT (DHHEMT)

We report the fabrication and characterization of pseudomorphic GaAs DHHEMTs. Higher current level and broader G/sub m/-I/sub d/s characteristics can be obtained simultaneously using DHHEMTs compared to those of SHHEMTs. For 1.25 /spl mu/m gate-length devices, the average f/sub T/ is 12 GHz and f/sub max/ is greater than 50 GHz. The high linearity, current drivability and f/sub max/ show that DHHEMTs are attractive for applications such as wireless communication.