Abstract
In this study, we combine the “top-down” lithography process and “bottom-up” self-assembly of block copolymer approach to generate nano-structure with well-oriented periodic arrays over large area. The first nano-template is a periodic Si grating made by dry etching, where a SiO2 layer is used as a hard mask to define the grating structure. We modify the concentration of process gases during etching, a steep sidewall and flat surface at the bottom of trenches is achieved. The second nano-template is with a grating feature size down to 50 nm, which is fabricated by e-beam lithography and a sidewall coating technique. The 3rd nano-template is square and hexagonal sharp-angle wells fabricated through multi-step photolithography. Then we take a process similar to making the second nano-template to get the final structure.