A process for cleaning a glass-coating reactor includes: (a) providing the reactor to be cleaned, wherein the reactor contains a glass substrate within a chamber and the chamber has an internal surface coated with at least one substance selected from the group consisting of Si3N4 or SiO2; (b) terminating a flow of a deposition gas to the reactor; (c) adding to the reactor at least one cleaning gas to react with the at least one substance to form at least one volatile product; and (d) removing from the reactor the at least one volatile product.