The selective area deposition of diamond films

Abstract

Diamond films were selectively nucleated and grown on single crystal (100) silicon by microwave plasma assisted chemical vapor deposition with submicron spatial resolution. A thermal silicon dioxide layer on the wafers was patterned by standard photolithography. Nucleation was performed by applying a dc bias of −250 to −350 V in a hydrogen-methane plasma. Lifting off the oxide layer by HF etching prior to growth delineated the nucleation pattern which was replicated by the diamond film after growth. The growth of polycrystalline diamond was performed in a hydrogen-carbon monoxide-methane mixture selected to facilitate (100) texturing. Individual faceted crystallites were grown on a square matrix of sites, with a pitch of 3 μm, by controlling the nucleation densities within the windows exposing the prenucleated silicon. However, the orientation of the crystallites was randomly aligned with respect to the (100) silicon lattice within the micron scale windows employed in this study.