Simple and low-cost nanofabrication process of nanoimprint templates for high-quality master gratings: Friction-induced selective etching

Abstract Gratings are core components in biochemical analysis, ultra-precision machine tools, and astronomy. However, the high complexity and cost of conventional fabrication processes severely prevent its wide commercial application. Here, we report a simple and inexpensive fabrication process based on friction-induced selective etching. A series of crucial technological issues in the fabrication process were systematically investigated and optimized to obtain high precision and practical master gratings. Compared with the conventional surface cleaning method, the magnetic stirring-assisted KOH etching process can nondestructively and completely remove chemical sediments. Moreover, the sharp and smooth diamond tip is less sensitive to the tip profile and can easily fabricate high-quality grating structures compared with the blunt diamond tip. Particularly, the line width/density and micromorphology of grating structures can be effectively controlled by the scratching load and etching time. By integrating the mature UV nanoimprint lithography technology, the master gratings fabricated by this improved process can be excellently replicated on the polymer surface. This work presents a solid progress toward the simple and inexpensive fabrication of Si-based master gratings and also provides detailed reference for fabricating intractable blazed and circular gratings.