Novel high drain breakdown voltage AlGaN/GaN HFETs using selective thermal oxidation process

Abstract

We have developed novel selective thermal oxidation process for AlGaN/GaN Heterostructure Field Effect Transistors (HFETs) and realized extremely high device isolation and high drain breakdown voltage device of over 100 V. The leakage current of device isolation between two active islands exhibited drastic reduction of 5 order of magnitude smaller than that of conventional mesa isolation process. Moreover, the fabricated 1.3 /spl mu/m-gatelength AlGaN/GaN HFETs exhibited maximum transconductance (gm/sub max/) of 130 mS/mm, maximum drain current (I/sub max/) of 500 mA/mm and excellent pinch off characteristics at high drain voltage of over 120 V.