Improved Current Collapse Phenomenon in AlGaN/GaN-on-Si HFETs Using Sacrificial GaO_x Process

Abstract

We have developed a novel passivation process employing a sacrificial GaO x process to suppress the current collapse phenomenon in AlGaN/GaN HFETs. Even with a conventional prepassivation process, surface damage during high temperature ohmic annealing cannot be avoided completely, which in turn induces surface trapping states. In this proposed process, the damaged surface after high temperature ohmic annealing was removed by a sacrificial GaO x process prior to SiO 2 surface passivation. As a result, surface damage induced trapping effects were successfully suppressed.