Three-dimensional nanoimprint using a mold made by focused-ion-beam chemical-vapor-deposition

Nanoimprint lithography (NIL) is a very useful technique by which the fabrication of various nanostructure devices. A conventional mold is delineated by EB lithography and dry etching which has usually two-dimensional (2-D) patterns. 3-D structures are required in various devices such as optical devices (micro-lenses, photonic crystals, etc.). FIB-CVD is very useful to fabricate 3-D structures, as we previously demonstrated with several 3-D nanostructures. Moreover, a very large Young's modulus over 600 GPa were confirmed by observation of diamond-like carbon (DLC) pillar mechanical vibration. These characteristics are advantageous to make 3-D mold. In this paper, we will report 3-D NIL using DLC mold by FIB-CVD. We used a commercial available FIB system (SMI9200: Seiko Instruments Inc.); a 30-keV beam of Ga ions was focused on the substrate, which was in a precursor ambient. We used phenanthrene (C/sub 14/H/sub 10/) as the source gas for the amorphous DLC growth.