Patterning Characteristics of Hole Patterns in Synchrotron Radiation Lithography

Abstract

The patterning characteristics of synchrotron radiation lithography for hole patterns using a low-contrast mask (contrast: 3.5) are investigated. A resolution of 110 nm provides a large exposure dose latitude of more than 10% when the proximity gap is less than 15 µm, and the replicated minimum hole size is 70 nm with a 10-µm gap. Resist pattern sizes from 110 to 360 nm are kept within ±10% with proximity gaps of less than 20 µm. However, the exposure dose margin to guarantee mask linearity decreases to several percent because of the different optimum exposure dose for each pattern. Pattern size correction using mask bias to improve the mask linearity and exposure dose margin is proposed.

Process improvement of high aspect ratio nano-gratings based on synchrotron x-ray

“…After that, Wang et al [16] used a unique nanopillar array technique to roughen the silicon substrate surface so that the resist or plated gold has good adhesion to the silicon wafer, providing a good method for thick resist film and large high aspect ratio structure in LIGA technology, as well as obtaining a gold absorption grating with a period of 4 μm and a height of 100 μm. To enhance the exposure intensity and lithography efficiency, Nakanishi et al [39] demonstrated that differences in pattern size on the mask plate lead to differences in the optimal exposure dose. To improve the accuracy of the lithographic patterns, they compensated the mask size so that the optimal exposure dose was the same for each pattern, which ensured the linearity of the mask and improved the lithographic efficiency.…”