[20a-S224-1~9] 7.3 Micro/Nano patterning and fabrication

[20a-S224-5] Improvement of Pattern Width Uniformity by Controlling Each Cell Transmittance in Liquid-Crystal-Display Matrix Exposure

〇Toshiyuki Horiuchi¹, Shota Haneishi¹, Yumika Yoshida¹, Hiroshi Kobayashi¹ (1.Tokyo Denki Univ.)

Keywords:maskless exposure system,LCD projector,transmittance control

A desktop-type maskless exposure system was developed by utilizing a commercial projector with liquid-crystal-display (LCD) panels. The system was handmade by replacing the magnifying projection optics with a camera lens for macro-photography. However, unfortunately, because the positions and angles of the light source and the projection lens were not precisely adjustable, the exposure light energy was largely distributed in the exposure field. For this reason, it was investigated that the patterns were homogeneously printed in the whole exposure field, if transmittance level of each element cell of the LCD panel was appropriately adjusted one by one. At first, it was tried to give transmittance distribution to each bright cell for compensating the exposure light intensity distribution. However, there remained large distribution of patterning status, and the pattern width uniformity was not improved much. For this reason, transmittance of dark cells was also adjusted next. As a result, the contrast between neighbored bright and dark cells was also homogenized, and printed pattern width distribution was notably improved .Widths of 4-pixel line-and-space (L&S) (37-μm L&S) patterns became almost uniform in the exposure field.