Micromachining of electroformed nickel mold using thick photoresist microstructure for imprint technology

作者:Shibata Takayuki*; Takahashi Yoichi; Kawashima Takahiro; Kubota Toshio; Mita Mamoru; Mineta Takashi; Makino Eiji
来源:Microsystem Technologies, 2008, 14(9-11): 1359-1365.
DOI:10.1007/s00542-007-0501-3

摘要

In order to fabricate polymer-based microstructures with feature sizes on the order of micrometers, we have been developing a microimprint technology with a fine nickel (Ni) mold instead of a conventional photolithography technique. The Ni mold was successfully fabricated by electroforming using a positive thick photoresist microstructure patterned on a silicon substrate as a replication master. The photoresist microstructure with excellent edge quality can be obtained under irradiation with single wavelength (g line) selected from a high-pressure mercury lamp. In addition, its sidewall angle in the range of 65 degrees to 84 degrees can be controlled precisely by varying the distance between a photomask and a photoresist surface. On the structured photoresist master, Ni was electroplated up to a thickness of about 110 mu m, and then removed from the master. In this process, two-step electroplating at different current densities was carried out in order to prevent deformation of the photoresist master due to stress generated in a Ni electrodeposit. With the Ni mold, fine patterns with a width of 10 or 30 mu m and a depth of 24 mu m were almost completely transferred to polymetric materials (PMMA). The geometrical dimensions of the fabricated PMMA microstructures were found to be only about 10% reduction against the Ni mold.

  • 出版日期2008-10