Abstract: Provided are improved methods for forming silicon films, particularly single-crystal silicon films from amorphous silicon films in which a single-crystal silicon substrate is prepared by removing any native oxide, typically using an aqueous HF solution, and placed in a reaction chamber. The substrate is then heated from about 350° C. to a first deposition temperature under a first ambient to induce single-crystal epitaxial silicon deposition primarily on exposed silicon surfaces. The substrate is then heated to a second deposition temperature under a second ambient that will maintain the single-crystal epitaxial silicon deposition on exposed single-crystal silicon while inducing amorphous epitaxial silicon deposition on insulating surfaces. The amorphous epitaxial silicon can then be converted to single-crystal silicon using a solid phase epitaxy process to form a thin, high quality silicon layer.