Patent ID: 7842588

Claim:
Method for forming a group-III metal nitride film attached to a substrate, the method comprising the procedures of: subjecting said substrate to an ambient pressure of no greater than 0.01 Pa; heating said substrate to a temperature of between approximately 500° C.-800° C.; introducing a group-III metal vapor to the surface of said substrate at a base pressure of at least 0.01 Pa, until a plurality of group-III metal drops form on said surface; introducing active nitrogen to said surface at a working pressure of between 0.05 Pa and 2.5 Pa, until group-III metal nitride molecules form on said group-III metal drops; maintaining said working pressure and said active nitrogen until said group-III metal nitride molecules diffuse into said group-III metal drops, forming nitride/metal solution drops, and until said nitride/metal solution drops turn into a wetting layer on said substrate; and continuing to increase the concentration of group-III metal nitride molecules in said wetting layer until all the group-III metal atoms contained in said wetting layer are exhausted, and said wetting layer transforms into a group-III metal nitride film.