임프린팅을 이용한 BiLaO 패터닝과 액정 디스플레이 소자의 응용
Patterning of BiLaO film using imprinting process for liquid crystal display
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초록
정렬 패턴을 전사공정을 이용하여 BiLaO 박막 위에 패터닝하고 소성온도에 따른 액정 배향 특성에 대하여 연구 하였다. 졸겔 공정을 제작한 BiLaO 은 유리 기판 위에 스핀코팅으로 증착한 후 미리 제작된 정렬패턴을 전사하여 100, 150, 200, 250℃ 의 온도에서 소성하였다. POM분석으로부터 200℃ 이하의 소성온도에서 액정배향은 균일하지 않았고, 250 ℃의 소성온도에서 균일한 액정 배향 특성을 확인 할 수 있었고, 결정 회절 법 분석으로 부터도 확인 가능하였다. 전사 공정 시 250 ℃의온도에서 패턴이 전사되었음을 Atomic force microscopy 을 통하여 확인 할 수 있었다. 250 ℃의 온도에서 전사된 정렬 패턴에 의하여 박막의 이방성을 획득 하였고 이방성 박막 위에서 액정 분자들이 고르게 배향 될 수 있었다. 따라서 BiLaO 산화막의 전사에 의한 액정 배향 공정은 소성온도에 영향을 받는다는 것을 확인 할 수 있었다.
Abstract
We demonstrate an effect of annealing temperature on imprinting process of BiLaO thin film for liquid crystalalignment. BiLaO prepared sol-gel process was deposited by spin coating on a glass substrate, and then transferred toa pre-fabricated aligned pattern which is fabricated on a silicon wafer by laser interference lithography. Thin film wasannealed at different temperature of 100, 150, 200, and 250 ℃. From the polarized optical microscopy analysis, the liquidcrystal orientation was not uniform at the annealing temperature of 200 ℃ or lower and the uniform liquid crystalalignment characteristics were confirmed at the annealing temperature of 250 ℃. From atomic force microscopy, thepattern was not transferred at a temperature of 200 ℃ or lower. In contrast, the pattern was transferred at 250 ℃. Anisotropy of the thin film was obtained by the alignment pattern transferred at a temperature of 250 ℃, and the liquidcrystal molecules could be evenly oriented on the thin film. Therefore, it was confirmed that the liquid crystal alignmentprocess by the imprinting process of the BiLaO oxide film was affected by the annealing temperature.
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