The authors report upon a low-resistance Ni/Al Ohmic contact to a nonpolar n -type a -plane GaN with respect to the annealing temperature. The Schottky behavior of the Ni/Al contact changes to a linear Ohmic behavior at a 700 °C annealing, at which the specific contact resistivity of the Ni/Al contact became as low as 5.8× 10-5 whereas that of a typical Ti/Al contact was 1.6× 10-3 π cm2. This improvement is attributed to a lowering of the Schottky barrier height via a Ni-Al interdiffused layer, formed at the interface between the metal and the nonpolar a -plane n -type GaN during the annealing process.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)