Highest current gain cutoff frequency with 0.08 mu m gate HEMT on InP

InGaAs/InAlAs HEMTS with mushroom profile gates smaller than 0.1 mu m were processed on InP substrate, showing that such devices can be fabricated with high yield using available electron beam technology. The combination of short gate and high 2DEG mobility and saturated velocity in InGaAs/InAlAs HEMTs on InP has led to three terminal devices with unprecedented speed. The actual gate lengths varied between 0.07 and 0.09 mu m. The maximum stable gain measured at 40 GHz varied between 14 and 16 dB with a stability factor k ranging from 0.7 to 0.35, respectively. These devices exhibit current gain cutoff frequencies in excess of 200 GHz and f/sub max/ values above 300 GHz. >