Abstract:
Complementary delta-doped AlGaAs/GaAs Heterojunction Field Effect Transistor
(CHFET) devices and circuits were fabricated using MBE and a 2μ non-planar gate
recess process. Several schemes were used in an attempt to improve the performance of
the p-channel HFETs. These included delta-doping, carbon-doping and dipole-doping.
Circuits and individual n- and p- channel devices were fabricated on a stacked delta-doped
complementary structure. The circuits failed to perform due to complications with
adjusting the threshold voltage. However, Individual devices were successfully
characterized, p-channel devices with extrinsic transconductances up to 14 mS/mm, n-channel
devices with extrinsic transconductances up to 120 mS/mm and a unity power
gain bandwidth of 5.5 GHz.
