1. Field of the Invention
This invention relates to methods for forming epitaxial films in various manufacturing process, such as in semiconductor manufacturing. More particularly, this invention relates to methods for depositing amorphous layers on single crystal substrates, then forming epitaxial films from the amorphous layers by solid phase epitaxy.
2. Description of the Related Art
Various semiconductor manufacturing processes require the formation of an epitaxial layer on an underlying single crystal substrate. In some cases, the epitaxial layer may be formed by direct deposition on the single crystal substrate, e.g., by chemical vapor deposition. However, in other cases, direct deposition is difficult.
Solid phase epitaxy is an alternate method to direct deposition for forming epitaxial films. Solid phase epitaxy involves the crystallization of an amorphous film to form an epitaxial film having a crystal structure patterned on the single crystal structure beneath it. Solid phase epitaxy is generally conducted by forming an amorphous film on a single crystal substrate, then crystallizing the amorphous film to form the epitaxial film. However, in many cases it is difficult to form the amorphous film on the single crystal substrate.