GATE AND RECESS FABRICATION TECHNIQUE FOR SUB-MILLIMETER-WAVE INP-HEMTS

摘要

A gate and recess fabrication technique for sub-millimeter-wave InP-based high electron mobility transistors (HEMTs) is presented. An ultra-short 30-nm T-shaped-gate is successfully fabricated by optimizing electron beam (EB) lithography and reactive ion etching (RIE) conditions, resulting in an extremely high cutoff frequency (f_t) of 469 GHz in a pseudomorphic HEMT (PHEMT). A 60-nm-gate PHEMT with an asymmetric gate-recess structure that has a longer drain-side recess exhibits a much-improved maximum oscillation frequency (f_(max)) of 503 GHz.