METHOD FOR SELECTIVELY GROWING DOPED EPITAXIAL FILM, AND METHOD FOR SELECTIVELY GROWING DOPED EPITAXIAL FILM

摘要

The invention improves the surface roughness of an epitaxial film having a high concentration doping, and improves device characteristics by decreasing contact resistance of the source/drain layer electrodes. In one embodiment, the processing surface of a substrate having at least a single crystal surface and an dielectric surface is exposed to a first deposition gas containing a source gas and a doping gas, forming a first doped thin film on the single crystal surface and wherein supply of the first deposition gas is stopped before a film is formed on the dielectric surface (S2). Next, the processing surface of the substrate is exposed to a second deposition gas containing a source gas and a doping gas, forming on the single crystal surface a second thin film with less dopant than the first thin film, wherein supply of the second deposition gas is stopped before a film is formed on the dielectric surface (S3). Subsequently, the processing surface of the substrate is exposed to a chlorine-containing gas, and etching is performed (S4). In this way, the dopant concentration of the second thin film is lower than that of the first thin film.