Dynamic variation of carrier transport properties of recessed Au-free ohmic contacts to InAlN/AlN/GaN on Si-wafer

Abstract

The temperature dependence of specific contact resistivity of recessed ohmic contacts was investigated to examine the carrier conduction mechanism in Ti/Al/W ohmic contacts on InAlN/AlN/GaN on Si wafer. The lowest specific contact resistivity of 2.36 × 10−5 Ω·cm2 was obtained from a sample with a half-etched InAlN layer. The barrier heights and donor concentrations of recessed contacts with various recess depths were calculated using a thermionic field emission model that showed good fitting with the experimental data. It was found that the rate of tunneling in carrier conduction decreased with increasing recess depth.