Fabrication and Performance of InAlN/GaN-on-Si MOSHEMTs with LaAlO_3 Gate Dielectric using Gate-First CMOS Compatible Process at Low Thermal Budget

摘要

A gate-first CMOS compatible process at low thermal budget to fabricate InAlN/GaN-on-Si MOSHEMTs is reported. This is made possible by a good quality LaAlO_3 gate dielectric (k ～ 21.8) and Hf/Al/Ta ohmic contacts that require low annealing temperature. The reverse leakage current of the W/LaAlO_3 gate stack remains low (＜ 3×10~(-7) mA/mm at -10 V) upon ohmic contact annealing at 600 ℃. The fabricated LaAlO_3 gate dielectric MOSHEMTs demonstrate a reasonable DC performance (I_(dsat) ～510 mA/mm, G_(max) ～ 44 mS/mm) for a 1 μm gate length device.