Gray scale lithography has been recently researched to make 3D structures such as a microlens, prism etc. In this research, a novel gray scale mask was fabricated by chrome mask and EB lithography system that can apply bitmap data (tiff form file) to drawing data. The gray scale was realized using half-tone pattern which consists of array of micro spots (diameters are 0.2μm - 1.6μm). Thick positive UV resist (AZ-p4620) on Si was exposed, defocusing the half-tone pattern by holding the gap of 80μm. Relation between gray scale value and depth was examined, and Fresnel lens pattern was formed on the resist.
ASJC Scopus subject areas
- Mechanical Engineering
- Electrical and Electronic Engineering