A process for producing a
silicon compound can minimize the number of steps and can form a desired compound in a low-temperature environment. The process comprises: allowing a radical of a
halogen gas to act on a member 11 to be etched, which is disposed within a chamber 1 and is formed of a material containing an element capable of forming a compound with Si, while keeping the member 11 at a relatively high temperature, to form a gas of a precursor 24, which is a compound of the material and the
halogen; holding a substrate 3 accommodated within the chamber 1 at a relatively low temperature, with the Si interface of the substrate 3 being exposed, to adsorb the precursor 24 onto the Si interface of the substrate 3; and then allowing the radical of the
halogen gas to act on the precursor 24 adsorbed onto the Si interface to reduce the precursor 24, thereby producing a compound of the material and Si.