In accordance with the present invention, improved methods for reducing the dislocation density of nitride epitaxial films are provided. Specifically, an in-situ etch treatment is provided to preferentially etch the dislocations of the nitride epitaxial layer to prevent threading of the dislocations through the nitride epitaxial layer. Subsequent to etching of the dislocations, an epitaxial layer overgrowth is performed. In certain embodiments, the etching of the dislocations occurs simultaneously with growth of the epitaxial layer. In other embodiments, a dielectric mask is deposited within the etch pits formed at the dislocations prior to the epitaxial layer overgrowth.
