A chemical vapor deposition process to replicate the finish and/or figure of preshaped structures.

摘要

A process is disclosed by which the finish and/or figure of polished preshaped structures (such as mirrors) can be replicated directly by chemical vapor deposition, with only minor polishing of the replica (18) being required to obtain a final product, and with the original substrate (12) being reusable for further replication. Relevant conditions under which the process can be carried out are given. Featured in the process is a pretreatment step prior to the deposition of a layer of silicon carbide to form the replica, which pretreatment step involves the formation on the polished substrate of an oxide layer and a carbon layer (16) of high finish and uniform thickness. The carbon layer allows easy separation of the substrate and replica which otherwise would be bound together.