레이저 빔 단면확대를 이용한 나노 복화공정의 패턴정밀도 향상에 관한 연구Fabrication of Precise Patterns using a Laser Beam Expanding Technique in Nano-Replication Printing (nRP) Process
A laser beam expanding technique is employed to fabricate precise nano-patterns in a nano-replication printing (nRP) process. In the nRP process, some patterns can be fabricated in the range of several microns inside on a polymerizable resin by using a volume-pixel (voxel) matrix that is transformed from a two-tone bitmap figure file. The liquid monomers are polymerized by means of a two-photon-absorption (TPA) phenomenon that is induced by a femtosecond (fs)-pulse laser. The yokels are generated consecutively to merge into adjoining yokels in the process of fabricating a pattern. The resolution of a fabricated pattern can be obtained under the diffraction limit of a laser beam by the two-photon absorbed polymerization (TPP). In this work, a beam-expanding technique has been applied to enlarge a working area and to fabricate precise patterns. Through this work, a working area is expanded by the technique as much as 2.5 times compared with a case of without a beam expanding technique, and precision of outside patterns is improved.