Patent ID: 7815970

Claim:
A method of preparing a substrate with an exposed surface for simultaneous deposition of a dual polarity Group III-nitride film, said method comprising: (a) performing a first nitridation of the substrate to cover the exposed surface of the substrate with a nitridation layer; (b) applying a buffer layer to the surface of the substrate with the nitridation layer thereon; (c) annealing the buffer layer; (d) selectively patterning the substrate surface comprising selectively removing a portion of the buffer layer from the substrate surface, thereby exposing a portion of the substrate surface; (e) optionally, annealing the selectively patterned substrate surface; and (f) performing a second nitridation of the substrate such that a portion of the substrate surface is covered with an exposed nitridation layer and the remaining portion of the substrate surface is covered with an exposed buffer layer.