Fabrication of Large-Area CoNi Mold for Nanoimprint Lithography

Abstract

A cobalt–nickel (CoNi) alloy stamp of 140 mm diameter and 300 µm thickness was fabricated for nanoimprint lithography (NIL) from a Si mother mold with nanofeatures by using a stress-free electroforming method. CoNi alloys were electrodeposited in a chloride bath, and the effect of the flow velocity of a plating solution on CoNi film stress was investigated. The compositions of CoNi alloy films were investigated by changing the flow rate and bath concentration of CoCl2. The stress of the CoNi deposit was reduced to almost zero in an electrolyte containing 0.008 M CoCl2 in the flow rate range of 1–2 m/s. The multiple duplication of a stress-free CoNi alloy stamp was carried out without the use of a costly Si mother mold. Duplicated patterns on the CoNi alloy stamp were compared with those of the Si mother mold by field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM).