The crystal orientation dependence in the p-type contact resistance of
wurtzite GaN is theoretically investigated by considering the k-direc
tional dependence of hole effective masses for the first time. The cur
rent-voltage characteristics of a metal-GaN junction has been calculat
ed by using the so-called tunnelling model which includes both heavy-
and light-hole transports. The obtained result suggests that the p-typ
e contact resistance will be reduced when [1 0 (1) over bar 0] and [0
1 0 0] faces are properly used for contact interfaces. (C) 1998 Elsevi
er Science B.V. All rights reserved.