Fabrication of a 120 nm gate-length lattice-matched InGaAs/InAlAs InP-based HEMT

A new PMMA/PMGI/ZEP520/PMGI four-layer resistor electron beam lithography technology is successfully developed and used to fabricate a 120 nm gate-length lattice-matched In0 53Ga0 47As/In0 52Al0 48As InP-based HEMT, of which the material structure is successfully designed and optimized by our group. A 980 nm ultra-wide T-gate head, which is nearly as wide as 8 times the gatefoot (120 nm), is successfully obtained, and the excellent T-gate profile greatly reduces the parasitic resistance and capacitance effect and effectively enhances the RF performances. These fabricated devices demonstrate excellent DC and RF performances such as a maximum current gain frequency of 190 GHz and a unilateral power-gain gain frequency of 146 GHz.