이광자 흡수 광환원 공정을 이용한 마이크로 금속형상 제작의 정밀화에 관한 연구

Abstract

A two-photon induced photoreduction process suggests a possibility for fabricating complicated metallic microstructures which can be applied to 3-D micro-circuits and optical devices, etc. The process employs the photoreduction of silver ions in a metallic solution which is composed of metallic salt (AgNO₃) and water-soluble polymer ((poly(4-styrenesulfonique acid) 18wt. % in H2O, (C8H8O3S)n)). In this process, the improvement of the resolution and the uniformity of fabricated metallic structures are important issues. To address these problems, continuous forming window (CFW) is obtained from a parametric study on the conditions of laser power and scanning velocity and the direct seed generation (DSG) method is proposed. Silver nano particles are uniformly generated in a metallic solution through the DSG method, which enables the decrease of a laser power to trigger the photoreduction of silver ions as well as the increase of metal contents in a metallic solution. So the two-photon induced photoreduction property of a metallic solution is improved. Through this work, precise silver patterns are fabricated with a minimum line width of 400 nm