Nanostructured Silicon Carbide Molds for Glass Press Molding

This paper reports the first result of press molding of Pyrex glass using a silicon carbide (SiC) mold with nanopatterns. First, the nanopatterns were formed on a silicon substrate by electron beam lithography and fast atom beam (FAB) etching. To transfer these patterns to SiC, SiC was deposited on the patterned silicon substrate, and the SiC surface was polished to mirror finish. Subsequently, a SiC ceramic plate was bonded to the polished SiC surface using sputter deposited nickel as an interlayer. Finally, the silicon substrate was etched to release the SiC mold. Using the fabricated SiC molds without an anti-sticking layer, we succeeded in press-molding Pyrex glass (Corning 7740) at 800 degC. In this process, we found surface roughening problem, which occurs in SiC atmospheric vapor deposition on FAB-etched areas. This is due to damage in silicon by FAB, and enhanced under the existence of surface natural oxide.