InP based heterostructure for medium power applications

In this paper a double doped InP based HEMT layer structure designed for power applications is presented. An electron density n/sub c/=5.1/spl middot/10/sup 12/ cm/sup -2/ and a mobility /spl mu/=8.4/spl middot/10/sup 3/ cm/sup 2//Vs at room temperature result in a maximum channel current density of 1000 mA/mm. The output conductance G/sub ds/ is limited to 27 mS/mm with a maximum transconductance G/sub m/ of 713 mS/mm for 0.2 /spl mu/m gate length. The cut-off frequency f/sub T/ is 99 GHz and the maximum oscillation frequency f/sub MAX/ is 218 GHz. Power measurements show a very low second and third harmonic component of -33 and -26 dBc which can be attributed to the G/sub m/ staying constant within 10% for a gate voltage swing of 0.9 Volt.