Studies on nanoimprint process parameters of copper by molecular dynamics analysis

A molecular dynamics analysis scheme is proposed to study nanoimprint processes by considering the following effects: temperature, punch velocity, spring back, etc. The nanoimprint process being studied in the proposed paper is similar to nanoimprint lithography, except that the material under investigation is metal. The nanoimprint process being simulated in the proposed paper is comprised of one punch and one specimen. By varying the environment temperature and the punch velocity, useful information has been obtained. If the environment temperature is higher, then the needed punching force becomes smaller. When increasing punch velocity, the needed punching force also increases. The internal energy of specimen under high temperature is smaller than that of low temperature. When increasing punch velocity, due to shorter relaxation time in the specimen, the absorbed energy will increase rapidly, and finally if it reaches the marginal value the specimen collapses. The spring back effect is an important factor to discuss. Since the imprinting energy is absorbed mainly by those atoms close to the punch, especially at both sides of punch, if as the punch leaves the specimen, the spring back phenomena of deformed-atomic structures in horizontal direction are more serious than in vertical direction.