Evaluation of a gate-first process for AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors with low ohmic annealing temperature**Project supported by the International Science and Technology Collaboration Program of China (Grant No. 2012DFG52260).

Abstract

In this paper, TiN/AlOx gated AlGaN/GaN metal–oxide–semiconductor heterostructure field-effect transistors (MOS-HFETs) were fabricated for gate-first process evaluation. By employing a low temperature ohmic process, ohmic contact can be obtained by annealing at 600 °C with the contact resistance approximately 1.6 Ω·mm. The ohmic annealing process also acts as a post-deposition annealing on the oxide film, resulting in good device performance. Those results demonstrated that the TiN/AlOx gated MOS-HFETs with low temperature ohmic process can be applied for self-aligned gate AlGaN/GaN MOS-HFETs.