1. 제 목 : Nanoimprint lithography 기술

2. 연 사 : 정 준호 박사 (한국기계연구원 나노공정장비 연구센터)

3. 일 시 : 2006년 3월 17일 (금) 오후 4시 30분 ~ 5시 30분

4. 장 소 : 301동 102호 세미나실

5. 내 용 : It is known that nanoimprint lithography (NIL) process could be used to create 10 nm features and be considerably less expensive than conventional photolithography. NIL process over a non-flat, flexible and transparent substrate could also be achieved. NIL process consists of two steps: embossing step and anisotropic etching step. In the embossing step, a stamp with nanoscale structures is pressed into a thin polymer or resin layer on a substrate, and then is separated from the layer after cool-down, UV curing or thermal curing. During the anisotropic etching process, the residual polymer is removed completely in the compressed area and selected nanoscale areas of the substrate are exposed for further processes such as etching and lift-off.

Ultraviolet-nanoimprint lithography (UV-NIL) is a promising method for cost-effectively defining nanoscale structures at room temperature and low pressure. In an attempt to apply a large area stamp to UV-NIL in a low vacuum environment, we proposed a new single-step UV-NIL process using an elementwise patterned stamp (EPS), which consists of a number of elements, each of which is separated by channels. Before pressing the EPS, low viscosity resin droplets with a nano-liter volume were dispensed on each element of the EPS. Experiments on UV-NIL were performed on an EVG620-NIL. Nano-scale features of the EPS were successfully transferred to wafers. Experiments showed that the EPS enables single-step UV-NIL using a large-area stamp in a low vacuum environment. We also proposed a new UV-NIL process that uses the EPS and additive gas pressurization to apply a large-area stamp to a high throughput step-and-repeat process at atmospheric conditions. The proposed step-and-repeat UV-NIL process required just four imprints to press an 8 in wafer. EPS features measuring 50 - 80 nm were successfully transferred onto the wafers. The experiments demonstrated that a 5 × 5 in2 EPS could be used with a step-and-repeat UV-NIL process to imprint 8 in wafers under atmospheric conditions.The latest researches are focused on the developmentof large-area NIL application technology for next-generation memory and display.

Two-dimensional (2-D) and three-dimensional (3-D) diamond-like carbon (DLC) stamps for ultraviolet nanoimprint lithography were fabricated with two methods: namely, a DLC coating process, followed by focused ion beam lithography; and two-photon polymerization patterning, followed by nanoscale-thick DLC coating. We used focused ion beam lithography to fabricate 70 nm deep lines with a width of 100 nm, as well as 70 nm deep lines with a width of 150 nm, on 100 nm thick DLC layers coated on quartz substrates. We also used two-photon polymerization patterning and a DLC coating process to successfully fabricate 200 nm wide lines, as well as 3-D rings with a diameter of 1.35 µm and a height of 1.97 µm, and a 3-D cone with a bottom diameter of 2.88 µm and a height of 1.97 µm. The wafers were successfully printed on an UV-NIL using the DLC stamps without an anti-adhesive layer. The correlation between the dimensions of the stamp’s features and the corresponding imprinted features was excellent.


6. 연사약력 :
1986-1990: B.S. in Precision Mechanical Engineering, Han-Yang University
1991-1993: M.S. in Precision Engineering, Korea Advanced Institute of Science and Technology
1993-1998: Ph.D. in Mechanical Engineering, Korea Advanced Institute of Science and Technology 
1998-1999: Post-doctoral researcher, Dept. of Mechanical Engineering, Korea Advanced Institute of Science and Technology
1999-2001: Post-doctoral researcher, Dept. of Mechanical Engineering, University of Illinois at Urbana-Champaign
2002-present: Senior research scientist, Nano-Mechanical Systems Research Center, Korea Institute of Machinery & Materials
2005-present: Associate Professor, University of Science & Technology

7. 문 의 : 기계항공공학부 방 영 봉 교수 (☏ 880-1697)