Electroplating of Metal Micro-structure using a Resist Micro-machined by Proton Beam Writing

In this paper,we report the fabrication of Ni structures by electroplating a Ni layer on micro-machined PMMA, a typical resist material. This process involves following steps, (i) Spin coating a resist layer of 5 mum thick PMMA. (ii) Exposure by PBW of 1.7 MeV focused proton beam.(iii) Development of the PMMA with IPA-water (7:3) for 20 min and rinsed in deionized water [4]. (iv) Deposition of a seed layer of 40-nm thick Au by magnetron sputtering for electroplating on the surface of the micro-structure, (v) Electroplating of the micro-structure using a typical nickel sulfamate bath solution. The bath temperature was kept at 35 degC. (vi) Removal of the PMMA structure was made by immersion in acetone and the Ni structure was rinsed in ethanol. Therefore, the PBW is a promising tool for fabrication of metal components such as a stamp for imprint lithography. Imprinting using the 300-nm-thick Ni structure on PMMA was also demonstrated.