Substantial Pinning of the Fermi Level of Plasma-Treated n-Type GaN Surfaces

The Schottky barrier height of plasma-treated n-type GaN was investigated according to the work functions of metals including Cu, Au, and Pt. The extracted S -parameter was as low as 0.17, and the density of surface states was as high as 5.4×10 13 states/(cm 2 ·eV), indicating substantial pinning of the Fermi level on plasma-treated n-type GaN surfaces.