This invention relates to the replication of surface features, and in particular to such replication to a metallic surface.
Surfaces and their features are replicated in a number of fields of technology. Replicas are sometimes made in order to study the features of the surface. In other instances, highly specialized patterns of features are formed on a master model using costly precision machining, etching, or photoetching techniques. The features are replicated from the master model to make large numbers of copies of the specialized features.
In one common example, a plastic sheet is placed against the surface whose features are to be replicated. The plastic is heated or partially dissolved so that it flows and closely contacts the features on the surface, allowed to cool or dry, and then stripped from the surface. If the procedure is performed carefully, the stripped plastic sheet has a surface profile and morphology that closely matches those of the surface being replicated. The plastic surface may then be used in this form, or it may be further processed, as by application of a metallic layer using a shadowing procedure.
Although useful for some applications, the plastic replicas are not sufficiently strong and durable for many others. Additionally, even when an overlying metallic layer is present on the plastic, the plastic replicas do not exhibit conventional metallic-like physical properties such as interaction with electromagnetic radiation and resistance to heat.
There have been attempts to make metallic replicas of master model surfaces to overcome the mechanical and physical shortcomings of the plastic replica approach. These attempts have to a large degree not been fully successful, because the replication of the surface features is not sufficiently faithful for fine-scale features on the order of one micrometer in width or smaller, because the metallic surface properties of the replica are undesirably altered, and other reasons.
A reliable approach to the fabrication of precise metallic replicas is needed in order to manufacture products such as durable secondary masters used in the production of products such as compact disks, optical devices, and directional plastic lenses, and also for direct applications such as light-absorptive panels for spacecraft applications. The present invention fulfills this need, and further provides related advantages.