Ni-Al ohmic contact to p-type 4H-SiC

Investigations on Ni/Al alloys to form ohmic contacts to p-type 4H-SiC are presented in this paper. Different ratios of Ni/Al were examined. Rapid thermal annealing was performed in argon atmosphere at 400 degrees C for 1 min, followed by an annealing at 1000 degrees C for 2 min. In order to extract the specific contact resistance, TLM test structures were fabricated. A specific contact resistance of 3 x 10(-5) Omega cm(2) was obtained reproducibly on Al2+ implanted p-type layers, having a doping concentration of 1 x 10(19) cm(-3). The lowest specific contact resistance value measured amounts to 8 x 10(-6) Omega cm(2). (c) 2006 Elsevier Ltd. All rights reserved.