50 nm MHEMT Technology for G- and H-Band MMICs

A metamorphic HEMT (MHEMT) MMIC technology including circuit applications is presented. The MHEMT layers are MBE grown on 4-inch GaAs wafers. The technology is based on a 50 nm gate length MHEMT and includes a 50 mum substrate backside process with dry etched through-substrate vias. For the electron confinement an ln_0.8Ga_0.2As/ln_0.53Ga_0.47As composite channel was used. The devices are passivated with BCB and SiN to achieve a median time-to-failure of 2.7 times 10⁶ h in air. Cut-off frequencies f_t and f_max of 375 GHz were extrapolated for a 2 times 15 mum gate width device. Low-noise amplifiers with more than 15 dB gain in the frequency range from 192 GHz to 235 GHz were realized.