A novel InGaAs/InAlAs insulated gate pseudomorphic HEMT with a silicon interface control layer showing high DC- and RF-performance

A novel InGaAs/InAlAs insulated gate pseudomorphic HEMT (IG-PHEMT) utilizing a silicon interface control layer (Si ICL) was successfully fabricated and its DC and RF performances were characterized. The device showed high transconductance of 177 mS/mm even for a gate length of 1.6 μm. As compared with the conventional Schottky gate PHEMTs, the gate leakage current was reduced by 4 orders of magnitudes and the gate breakdown voltage was increased up to 39 V. Well-behaved RF characteristics with the current gain cutoff frequency, f
_T
, of 9 GHz and the maximum oscillation frequency, f
_max
, of 38 GHz were obtained for the 1.6 μm-gate-length device.