Abstract
Recent years, artificial optical functional materials are collecting attention. However, it is necessary to produce huge number of metallic nanostructures of several 100 nm or less in order to realize such functional materials. In order to address this problem, the authors aim to develop an efficient nanofabrication process of metallic nanostructures utilizing nanoembossing technique. In this paper, the embossed height of nanostructures that can be formed on metal thin films by nanoembossing was examined from both experimental and numerical study. Experimentally, a diamond mold having nanohollows of various shapes and sizes was pressed onto thin gold films coated on quarts substrates. Analytically, a plane strain model was created, and analysis was conducted on various combinations of groove width and contact width of mold to derive a formula that enables to estimate the embossed height. As a result of experiment, it was found that the embossed heights depend on the position of hollows in the contact area of the mold. As a result of comparing the experiment and the analysis, it was found that the ratio of the embossed heights to the film thickness of the nanostructures arranged parallel to the outer side of the square mold show linearity to the analysis value. In addition, it was shown that the slope of the approximate straight lines vary depending on the film thickness, and it is suggested that the cause is the influence of the internal structure of the metal thin film and the adhesion between the substrate and the metal thin film.
