Self-aligned process for emitter- and base-regrowth GaNHBTs and BJTs

The development of a self-aligned fabrication process for small emitter contact area (2, x 4 mum(2)) GaN/AlGaN heterojunction bipolar transistors and GaN bipolar junction transistors is described. The process features dielectric-spacer sidewalls, low damage dry etching and selected-area regrowth of p-GaAs(C) on the base contact or n-GaN/ AlGaN on the emitter contact. Series resistance effects are still found to influence the device performance. (C) 2001 Elsevier Science Ltd. All lights reserved.