研究生: |
張劭儒 Shao-Ju Chang |
---|---|
論文名稱: |
含氫非晶碳薄膜的氬氣電漿浸沒處理及其液晶配向的研究 Liquid Crystal Alignment on the a-C:H Films Treated with Ar Plasma Immersion |
指導教授: |
黃振昌
J. C. Hwang |
口試委員: | |
學位類別: |
碩士 Master |
系所名稱: |
工學院 - 材料科學工程學系 Materials Science and Engineering |
論文出版年: | 2006 |
畢業學年度: | 94 |
語文別: | 中文 |
論文頁數: | 90 |
中文關鍵詞: | 非晶碳 、氬氣電漿 、液晶配向 、離子轟擊 |
外文關鍵詞: | a-C:H, Ar plasma, liquid crystal alignment, ion bombardment |
相關次數: | 點閱:2 下載:0 |
分享至: |
查詢本校圖書館目錄 查詢臺灣博碩士論文知識加值系統 勘誤回報 |
本論文研究一種新的液晶配向技術,此技術的重點是利用氬氣(Ar)電漿浸沒處理斜向放置於基板上之含氫非晶碳膜(hydrogenated amorphous carbon,簡稱a-C:H),經此製程處理過的a-C:H膜有利於液晶配向。本研究採用平面型電感式偶合電漿系統所產生之Ar電漿,進行Ar離子轟擊處理。除了觀察不同斜向放置角度、Ar電漿處理時間與試片基座所施加之脈衝負偏壓大小對a-C:H配向膜的配向效果影響外,並提出一理論模型來探究造成液晶配向效果之原因。
為了確定經過各種不同製程條件處理過之a-C:H配向膜的液晶配向效果,本研究也將經Ar電漿浸沒處理過之a-C:H配向膜組成液晶晶胞樣品,以進行偏光顯微鏡、預傾角與水平錨定強度的量測。此外,本實驗也利用接觸角測量儀、原子力顯微鏡、Raman光譜儀、UV-Vis穿透光譜儀與X-ray光電子能譜儀等儀器,探討a-C:H配向膜經過Ar電漿浸沒處理前後之性質變化。最後則採用Langmuir probe對本研究所使用之電漿系統進行電漿特性分析,以了解形成液晶配向效果之原因。
研究結果得知,a-C:H配向膜的斜向放置角度為0o時,並無液晶配向效果。當斜向放置角度為30o時就呈現液晶配向效果,但對比低且缺陷密度高。然而,當斜向放置角度提升至60o時,可以大幅提升液晶配向之效果。此外,本研究亦發現可藉由調整電漿處理的條件加以控制液晶分子之預傾角。在200瓦的射頻功率下,利用Ar電漿浸沒處理斜向放置角度為60o的a-C:H配向膜,於基座上外加1000 伏特的脈衝負偏壓,在經過10~15分鐘之電漿處理後,預傾角會出現最大值,約2.0o。同時,預傾角大小也會隨著a-C:H配向膜所施加的脈衝負偏壓降低而增加。同樣在200瓦的射頻功率下,利用Ar電漿浸沒處理斜向放置角度為60o的a-C:H配向膜10分鐘後,研究結果顯示在無外加偏壓的情況下預傾角會出現最大值,約2.6o。
本研究認為利用Ar電漿浸沒處理斜向放置的a-C:H配向膜之配向機制為在Ar電漿浸沒處理的過程中,因電漿密度不均勻分布,造成電漿中sheath厚度不均勻,導致Ar離子斜向轟擊a-C:H表面所致。
Abstract
The objective of the thesis is to study a new plasma immersion technique for liquid crystal (LC) alignment. The key step of this technique is to immerse in Ar plasma on sample holders with different holder-tilted angles, which is favorable to LC alignment. In this research, a planar-type inductive-coupled plasma system is used to generate Ar plasma for the plasma immersion treatment. Several plasma parameters such as different holder-tilted angles, treated time, and pulsed biased voltage have been used to modify the surface of a-C:H films to investigate the effect of LC alignment. In addition, a theoretical model is proposed to explain the phenomenon of LC alignment for the Ar plasma immersion treatment.
In order to study the LC alignment properties of the treated a-C:H films, different LC cells were assembled for the measurement of polarized optical microscope, pretilt angle, and azimuthal anchoring strength. Moreover, the contact angle instrument, atomic force microscope (AFM), Raman spectroscope, UV-Vis spectroscope, and X-ray photoelectron spectroscope (XPS) were also used to characterize a-C:H films with and without Ar plasma immersion treatment. A Langmuir probe was used to measure the plasma characteristics in order to analysis the mechanism of the LC alignment.
Experimental data indicate that no LC alignment appears for the a-C:H films treated at the holder-tilted angle of 0o; LC alignment which exhibits low contrast and high defect density for the a-C:H films treated at a holder-tilted angle of 30o. The quality of LC alignment is greatly improved for the a-C:H films treated at a holder-tilted angle of 60o. Furthermore, the pretilt angle of LC molecules can be adjusted to some extent by changing the experimental parameters of Ar immersion plasma treatment. In one case, a-C:H films, biased with a pulse voltage of -1000 V at the holder-tilted angle of 60o, was treated with Ar plasma immersion at a RF power of 200 W. A maximum magnitude (about 2.0o) of pretilt angle is achieved after the Ar plasma treatment for 10~15 minute. In addition, the magnitude of pretilt angle can be controlled by altering the pulsed biased voltage. The pretilt angle increases as the pulsed biased voltage decreases. A maximum magnitude (about 2.6o) of pretilt angle could be achieved after treating a-C:H films in the Ar plasma at a RF power of 200 W at zero pulsed biased voltage at the holder-tilted angle of 60o.
The mechanism for LC alignment, using a-C:H films treated with Ar plasma immersion, is attributed to the non-uniform thickness of the sheath layer. The non-uniform sheath width, generated by the inhomogeneous plasma density distribution in the planar-type ICP system, results in the oblique incidence of Ar onto the a-C:H film surface.
第一章
[1] S. -H. Paek, C. J. Durning, K. -W. Lee, and A. Lien, J. Appl. Phys. 83, (1998) 1270
[2] K. -W. Lee, A. Lien, J. H. Stathis, and S. -H. Paek, Jpn. J. Appl. Phys. 36, (1997) 3591
[3] S. Kobayashi, and Y. Iimura, SPIE 123, (1994) 2175
第二章
[1] J. J. Pouch and S. A. Alterovitz, Properties and Characterization of Amorphous Carbon Films (Trans Tech, U.S.A., 1990) P. 3
[2] J. Robertson, Mater. Sci. Eng. R 37, 129 (2002)
[3] J. J. Pouch and S. A. Alterovitz, Properties and Characterization of Amorphous Carbon Films (Trans Tech, U.S.A., 1990) P. 4
[4] S. E. Rodil, R. Olivares, and H. Arzate, Bio-Medical Materials and Engineering 15, 101 (2005)
[5] P. Chaudhari, et al, Nature 411, 56 (2001)
[6] J.-Y. Hwang, Y.-M. Jo, D.-S. Seo, S. J. Rho, D. K. Lee, and H. K. Baik, Jpn. J. Appl. Phys. 41, L654 (2002)
[7] H. J. Ahn, S. J. Rho, K. C. Kim, J. B. Kim, B. H. Hwang, C. J. Park, and H. K. Baik, Jpn. J. Appl. Phys. 44, 4092 (2005)
[8] S. R. P. Silva, Properties of Amorphous Carbon (INSPEC, U.K., 2003) P.577
[9] A. Grill, Thin Solid Films, 355~356, 189 (1999)
[10] J. Hong, A. Goullet, and G. Turban, Thin Solid Films, 364, 144 (2000)
[11] C. J. Huang, Y. K. Chih, J. Hwang, A. P. Lee, and C. S. Kou, J. Appl. Phys. 94, 6796 (2003)
[12] C. H. Wei, C. H. Chen, C.-M. Yeh, M. Y. Chen, J. Hwang, A. P. Lee, and C. S. Kou, J. Electrochem. Soc. 152, C366 (2005)
[13] 陳人豪,「類鑚薄膜在液晶配向層上的應用」,國立成功大學光電工程與科學所碩士論文 (2004)
[14] W. Gibbons, P. Shannon, S. Sun, and B. Swetlin, Nature 351, 49 (1991)
[15] K. Takatoh, M. Hasegawa, M. Koden, N. Itoh, R. Hasegawa, and M. Sakamoto, Alignment Technologies and Applications of Liquid Crystal Devices (Taylor & Francis, London and New York, 2005) P.93
[16] K. Y. Wu, C.-H. Chen, C.-M. Yeh, J. Hwang, P.-C. Liu, C.-Y. Lee, C.-W. Chen, H. K. Wei, C. S. Kou, and C.-D. Lee, J. Appl. Phys. 98, 083518 (2005)
[17] J. S. Gwag, K.-H. Park, D. J. Kang, C. G. Jhun, H. Kim, S. J. Cho, T.-H. Yoon, and J. C. Kim, Jpn. J. Appl. Phys. 42, L468 (2003)
[18] J. P. Doyle, et al., Nucl. Instr. and Meth. In Phys. Res. B 206, 467 (2003)
[19] K. C. Kim, H. J. Ahn, J. B. Kim, B. H. Hwang, and H. K. Baik, Langmuir 21, 11079 (2005)
[20] K. Kurhara, A. Egami, and M. Nakamura, J. Appl. Phys. 98, 084907 (2005)
[21] F. F. Chen, Introduction to Plasma Physics and Controlled Fusion (Plenum Press, New York, 1983)
[22] 謝璋豪,「He電漿離子佈植製作Smart-Cut」,國立清華大學材料所碩士論文 (2002)
[23] A. Grill, Cold Plasma in Materials Fabrication From Fundamentals to Application (the Institute of Electrical and Electronics Engineers, New York, 1994) P.15
[24] A. Grill, Cold Plasma in Materials Fabrication From Fundamentals to Application (the Institute of Electrical and Electronics Engineers, New York, 1994) P.14
[25] 蔡振明,「電漿離子佈植中鞘層動態分析及其應用」,國立清華大學物理所博士論文 (2004)
[26] M. A. Lieberman, and A. J. Lichtenberg, Principles of Plasma Discharges and Materials Processing (John Wiley & Sons, Inc., New York, 1994) P.164
第三章
[1] 吳坤益,「經電漿處理非晶質碳膜的液晶配向性質」,國立清華大學材料科學與工程所碩士論文 (2005)
[2] 蔡振明,「電漿離子佈植中鞘層動態分析及其應用」,國立清華大學物理所博士論文 (2004)
[3] 劉瑞祥譯,「液晶之基礎與應用」 (國立編譯館,台北市,1996) P.41
[4] 劉瑞祥譯,「液晶之基礎與應用」(國立編譯館,台北市,1996) P.42
[5] T. J. Scheffer and J. Nehring, J. Appl. Phys. 48, 1783 (1977)
[6] K. Shirota, M. Yaginuma, K. Ishikawa, H. Takezoe, and A. Fukuda, Jpn. J. Appl. Phys. 34, 4905 (1995)
[7] 吳信穎,「離子轟擊聚亞醯胺薄膜的液晶配向特性之研究」,國立交通大學電子物理所碩士論文 (2003)
[8] T. Akahane, H. Kaneko, and M. Kimura, Jpn. J. Appl. Phys. 35, 4434 (1996)
[9] Y. Saitoh, and A. Lien, Jpn. J. Appl. Phys. 39, 1743 (2000)
[10] 王智杰,「離子轟擊聚亞醯胺薄膜對液晶配向的研究」,國立交通大學電子物理所碩士論文 (2002)
[11] 陳嘉明、劉慧玫、李文欽、范楊宜,「光配向技術」,工業材料210 (工業技術研究院,新竹市, 2004) P.202
[12] G. Navascues, Rep. Prog. Phys. 42, 1131 (1979)
[13] J. Robertson, Mater. Sci. Eng., R. 37, 246 (2002)
[14] 汪建民,「材料分析」(中國材料科學學會,台北市,1998) P.353
[15] J. C. Vickerman, Surface Analysis: the principal techniques (John Wiley & Sons, U.K., 1997) P. 74
[16] 吳倉聚,「微波激發之大面積高密度表面電漿源之研究」,國立清華大學物理所博士論文 (2000)
第四章
[1] J. Robertson, Mater. Sci. Eng., R. 37, 246 (2002)
[2] J. Schwan, S. Ulrich, and V. batori, J. Appl. Phys. 80, 440 (1996)
[3] 吳坤益,「經電漿處理非晶質碳膜的液晶配向性質」,國立清華大學材料科學與工程所碩士論文 (2005)
第五章
[1] P. G. deGennes and J. Prost, The Physics of Liquid Crystals (Clarendon Press, Oxford, 1993), P. 166
[2] K. Takatoh, M. Hasegawa, M. Koden, N. Itoh, R. Hasegawa, and M. Sakamoto, Alignment Technologies and Applications of Liquid Crystal Devices (Taylor & Francis, New York, 2005), P. 31
[3] M. E. Adel, R. Kalish, and S. Prawer, J. Appl. Phys. 62, 4096 (1987)
[4] P. B. Leezenberg, W. H. Johnston, and G. W. Tyndall, J. Appl. Phys. 89, 3498 (2001)
[5] T. P. Tougas and W. G. Collier, Anal. Chem. 59, 396 (1987)
[6] J. Ruehe, G. Blackman, V. Novotny, T. Clarke, G. B. Street, and S. J. Kuan, J. Appl. Polym. Sci. 53, 825 (1994)
[7] M. Yanagisawa, STLE Special Publications SP-36, 25 (1994)
[8] J. P. Doyle, et al., Nucl. Instr. and Meth. in Phys. Res. B 206, 467 (2003)
[9] J. Stohr, M. G. Samant, J. Luning, A. C. Callegari, P. Chaudhari, J. P. Doyle, J. A. Lacey, S. A. Lien, S. Purushothaman, and J. L. Speidell, Science 292, 2299 (2001)
[10] K. Y. Wu, C.-H. Chen, C.-M. Yeh, J. Hwang, P.-C. Liu, C.-Y. Lee, C.-W. Chen, H. K. Wei, C. S. Kou, and C.-D. Lee, J. Appl. Phys. 98, 083518 (2005)
[11] O. Renault, D. Samour, J. -F. Damlencourt, D. Blin, F. Martin, S. Marthon, N. T. Barrett, and P. Besson, Appl. Phys. Lett. 81, 3627 (2002)
[12] K. Takatoh, M. Hasegawa, M. Koden, N. Itoh, R. Hasegawa, and M. Sakamoto, Alignment Technologies and Applications of Liquid Crystal Devices (Taylor & Francis, London and New York, 2005) P.93
[13] J.-Y. Hwang, Y.-M. Jo, D.-S. Seo, S. J. Rho, D. K. Lee, and H. Koo Baik, Jpn. J. Appl. Phys. 41, L654 (2002)
[14] D.-S. Seo, J. Appl. Phys. 86, 3594 (1999)
[15] S. J. Sung, J.-W. Lee, H.-T. Kim, and J. K. Park, Liq. Cryst. 29, 243 (2002)
[16] R. E. Whan, Materials Characterization, ASM Handbook 10 (ASM International, 1992) P.62
[17] K. C. Kim, H. J. Ahn, J. B. Kim, B. H. Hwang, and H. K. Baik, Langmuir 21, 11079 (2005)
第六章
[1] P. Chaudhari, et al, Nature 411, 56 (2001)
[2] Y. Kawanishi, T. Tamaki, M. Sakuragi, T. Seki, Y. Suzuki, and K. Ichimura, Langmuir 8, 2601 (1992)
[3] M. A. Lieberman, and A. J. Lichtenberg, Principles of Plasma Discharges and Materials Processing (John Wiley & Sons, Inc., New York, 1994) P.164