RECESSED GATE GAN MODFETS

MODFETs, with and without gate recess, were fabricated on a GaN/Al0.27 Ga0.73N heterostructure. The gate recess etch was performed with an EC R etch. The gate recess etch improved the maximum transconductance fro m 23 to 45 mS/mm, f(t) from 11.4 to 14 GHz, and f(max) from 21.2 to 42 .5 GHz. The physical gate length of 0.25 mu m before recess etch incre ased to 0.4 mu m due to the etching of the resist. Through gate recess , the decrease of the distance between the gate and 2DEG increased the maximum transconductance and the decrease of the effective gate lengt h increased f(t) and f(max). (C) 1997 Elsevier Science Ltd.