Low-Resistance Si/Ti/Al/Ni/Au Multilayer Ohmic Contact to Undoped AlGaN/ GaN Heterostructures

Abstract

A Si/Ti/Al/Ni/Au metallization scheme was investigated for the formation of very low ohmic contacts on undoped AlGaN/GaN heterostructures, The influences of the silicon layer thickness and the annealing temperature on the contact resistance were studied using linear transmission line model (TLM) patterns. A contact resistance of 0.23 Ω mm, corresponding to a specific contact resistance of 1.06 × 10-6 Ω cm2, was achieved with a 30 Å thick silicon layer annealed at 800°C for 30 s. © 2004 The Electrochemical Society. All rights reserved.