Performance of 4' Wafer-Scale Thermoset Working Stamps in Hot Embossing Lithography

摘要

In order to reduce the cost for stamps featuring nanometer structures in a hot embossing lithography (HEL) process the production and performance of working stamps made of thermoset polymer are of interest. Fabrication of stamps made of thermosetting material on silicon substrates by hot embossing with 2 x 2 cm~2 templates and their replication by HEL has already been demonstrated. In this paper the enlargement of this principle to 4 inch wafer-scale is presented. Two procedures to obtain working stamps by hot embossing are compared, one solely based on hot embossing, the other enhanced by additional UV-exposure. The produced working stamps are tested for performance under standard embossing conditions and the topic of anti-sticking layers, a key issue in all large area imprint applications is addressed. Two methods of tailoring adhesion properties of thermosets are proposed, plasma-depositing a fluorinated film and coating with a self-assembled monolayer of fluoroalkyltrichlorosilane, only the former of which was employed successfully. The achieved fidelity of pattern replication with working stamps and imprints thereof is assessed by cross-sectional SEM investigation, showing only the UV-enhanced method to be well suited for the task of obtaining low-cost replications of silicon stamps.