The Molded Mask Method: The Origin of Nanoimprint Lithography

This paper describes the invention of the molded mask method in the 1970s, which is considered to be the origin of current nanoimprint lithography. The molded mask method was proposed and developed in order to fabricate fine patterns and three-dimensional structures by combining molding technology and dry etching technology. The concept was the same as the technology now called nanoimprint lithography. In the 1970s, we had the idea that even very fine patterns (as small as ten nanometers across) could be fabricated by the molded mask method based on the similarity of this approach with specimen preparation for electron microscopy. How the molding mask method was born, the results of demonstration experiments, and studies conducted in the 1970s to solve technical problems are described in this paper. Recent progress in and applications of current nanoimprint lithography are also discussed with reference to the molded mask method.