Effect of metal type on the contacts to n-type and p-type GaN

The electrical properties of various metal contacts to both n-type and p-type GaN were investigated to determine the underlying trend between the metallic contact workfunction and the resultant Schottky barrier height between the said contact and the GaN material. It is concluded that, contrary to the expected trend, Fermi level pinning is not only present but is quite strong, with the effect being greater in the p-type material. The S factor (:the index of interface behaviour) was seen to be reduced from 1.00 to 0.21 and 0.01 for n and p-type GaN, respectively. (C) 1998 Elsevier Science B.V. All rights reserved.