High aspect pattern fabrication by nano imprint lithography using fine diamond mold

Fabrication of high aspect ratio patterns with an aspect ratio larger than 10 is attempted by nano imprint lithography. A fine mold using a chemical vapor deposition (CVD) diamond layer is newly developed by electron cyclotron resonance (ECR) using Cl-2-O-2 gas. Narrow grooves less than 100 nm in width and 1.0 mum in depth are successfully obtained. Using medium molecular weight PMMA (M-w = 350 k) and with slow advance of the cooling sequence in the imprint process, the fatal error of the polymer fracture is eliminated at the mold release process. Based on the advanced process, we first demonstrate the fabrication of high aspect ratio patterns over 20 with 80 nm line width, however, the polymer might be stretched during the mold release process.