Metal gate strained silicon MOSFETs for microwave integrated circuits

Abstract

In this work a III-V MODFET fabrication process has been adapted to fabricate metal gate silicon based MOSFETs. A range of MOSFETs with gate lengths varying from 1 μm to 120 nm were fabricated and all showed good transistor action. The gate metal was Ti/Pd/Au 200 nm thick and both pyramidal and T shaped gates were fabricated. The parasitic gate-source capacitance was reduced by using a spin on dielectric. The strained silicon MOSFETs with rectangular 0.3 μm Ti/Pd/Au gates had measured fT and fmax, of 11 GHz and 12 GHz respectively. By de-embedding the parasitic pad capacitance the intrinsic fT and fmax are 20 GHz and 21 GHz.