Topography transfer method with aspect ratio scaling

Abstract

The present invention is a method of applying a topographical surface to a part such as a substrate without the need for low temperature softening of that part while retaining high aspect ratios and densely packed features in that topography. A substrate, selected for its ability to be processed at a given desired temperature, has a layer of material applied to its surface. This layer is selected, among other reasons, for its ability to be molded. Typically, it is expected that the substrate will be able to withstand the higher temperatures of semiconductor post-processing whereas the applied layer will be moldable at low temperatures. This combination enables low cost embossing of a topography into this surface layer. The present invention comprises means to transfer this topography from the low temperature material into the higher temperature substrate. In addition, the present invention comprises a means to scale the aspect ratio of the features of that topography when it is transferred into the substrate material. Since the sidewall angle must be opened enough to permit demolding of the master form from the substrate after molding, some very vertical sidewall angles may not be possible during a molding-demolding operation. The present invention is a means to achieve steeper sidewall angles on features in a substrate where those features are applied by way of a molding process.

Dependencies are inferred from the claim text.