OS2-2-8 ナノスケールシリコンモールドへのDLC保護膜の形成(OS2 三次元の微細形状創成技術(2))

Abstract

Nanoimprint lithography is expected to be an alternative technology of photolithography. However, durability and anti-sticking property of the molds against imprinted films are critical problem. In this study, the diamond like carbon (DLC) coating was applied to develop harder, smoother and more hydrophobic Si mold, and thermal nanoimprint was conducted. Imprint pressure and temperature were 4〜5 MPa and 150℃ respectively. The DLC films were deposited on nano-scale trench patterns by using a bi-polar Plasma Based Ion Implantation and Deposition (bipolar PBII&D). The Si molds with line-and-space patterns were prepared using EB lithography and the width of line was varied from 150 nm to 2500 nm. The surfaces of Si molds were cleaned by Ar+ ion bombardment before DLC coating. The deposition parameters of DLC films in the bipolar PBII&D process such as positive pulse voltage, negative pulse voltage and deposition time were changed. SEM image of Si mold after DLC coating shows that the DLC film was coated on the Si mold very uniformly. Also, SEM images of imprinted patterns with DLC-coated Si mold apparently show that DLC coatings on the Si molds quite improve nanoimprint properties. We also measured the forces per area which were needed to lift off the transferred films from molds. The force was reduced by 40% when the mold was coated with DLC film. The nanoscale three dimensional DLC coating was performed successfully by bipolar PBII&D and DLC coating is very effective to anti-sticking layer for nanoimprint lithography process.