A novel gate process for InP based HEMTs with gate length from 0.06 to 0.2 /spl mu/m

A novel, fast and reliable process for making T-shaped gates has been developed. It uses two PMMA layers and one PMGI resist layer which have completely selective developers that result in a large process window. Using this process scheme, gate lengths from 60 to 200 nm have easily been made in the same process step. The processed InP-HEMTs show excellent dc and rf-performance. The process has a good control of the gate lengths and give a high yield, and is therefore suitable for mass production of HEMTs and MMICs.