CHEMICAL VAPOR DEPOSITION PROCESS TO REPLICATE THE FINISH AND 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 being required to obtain a final product, and with the original substrate 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 of high finish and uniform thickness. The carbon layer allows easy separation of the substrate and replica which otherwise would be bound together.