反射異向性光譜是一種非接觸性的表面探測技術，透過光學反射的方式對基板進行表面量測。當待測物品表層分子結構具有異向性時，我們便可透過此技術測得訊號值。反射異向光譜其高靈敏度的表面探測功能被運用在半導體磊晶的即時監控上已經發展的相當成熟；然而在顯示器的液晶配向膜這一環，由於量測的異向性光譜尚未完全定標，因此還無法明確指出異向峰值與配向膜內部分子指向的關係。
透過摩擦聚亞醯胺薄膜去達到液晶配向，以改變摩擦的次數及入毛深度來調變對薄膜的摩擦強度。從結果發現：經過摩擦後的薄膜會出現異向性，在特定的波段會出現峰值訊號。峰值訊號會隨著摩擦次數的不同而改變。同時進行預傾角的量測，並將數據與反射異向性光譜進行交互比對，以查證特徵峰值訊號與預傾角之間是否存在著一定的依賴趨勢。另外，利用表面自由能量測儀去探討表面張力與液晶傾角的關聯性，嘗試將反射異向性光譜、表面自由能與液晶預傾角三者綜合討論。
本實驗亦嘗試由樣品背面量測反射異向訊號，證實反射異向性系統並非只能侷限在表面的量測。發現樣品背面量測的訊號會由於樣品的入射與反射光經過兩次玻璃基板，造成在紫外光區間(200nm~300nm)的訊號被吸收掉，其餘波段的結果與正面量測幾近相同。

Reflectance anisotropy spectroscopy is a non-contact technique for surface detection. which means through the optical reflection from surface of the substrate measured. Because of its high sensitivity, RAS is used for in real-time control of semiconductor epitaxy. On our study, RAS is used to study the surface characteristics of liquid crystal alignment layer.
We used rubbing for polyimide film to achieve alignment purposes. The rubbing strength is determined by adjusting the pile impress and the number of rubbed. We found that the anisotropy spectroscopy will appear after rubbing. And the strength of RA signals changes with photon energy of the probe beam. The pretile angle of the liquid crystal sandwiched in between rubbed PI show certain degree correlation with RA strength. In addition, using surface free energy measurement to explore the relationship with pretilt angle and try to connect three of them.
We also tried to measure the reflection signal from the sample back. We found the signal of sample back would decay in UV region and it may be a result of UV absorption in the substrate.

中文論文審定書....................................................... i
英文論文審定書....................................................... ii
致謝................................................................ iv
中文摘要............................................................. v
英文摘要............................................................ vi
第一章 序論.........................................................1
第二章 液晶及其應用介紹.............................................2
2.1 液晶簡介.................................................2
2.2 液晶種類.................................................2
2.3 秩序參數.................................................5
2.4 光學特性.................................................5
2.5 液晶配向層...............................................7
2.5-1 液晶分子的配向模式..................................8
2.5-2 摩擦配向...........................................10
第三章 反射異向性光譜..............................................11
3.1 RAS的發展與應用.........................................12
3.2 RAS的原理...............................................12
3.2-1 各向同性與異向性..................................12
3.2-2 電磁波的反射與透射................................12
3.2-3 Epioptics.........................................15
3.3 RAS的系統架設...........................................16
3.4 RAS系統儀器與儀控軟體...................................17
3.4-1 光學元件與分析儀器................................17
3.4-2 儀控軟體..........................................23
3.5 RAS系統架設理論.........................................24
第四章 預傾角......................................................29
4.1 預傾角簡介..............................................29
4.2 預傾角量測原理..........................................29
4.3 預傾角量測架設..........................................32
第五章 樣品製備....................................................33
5.1 材料介紹................................................33
5.2 基板與液晶盒的製作......................................34
5.2-1清洗ITO玻璃........................................35
5.2-2 聚亞醯胺薄膜塗佈..................................35
5.2-3 摩擦處理聚亞醯胺薄膜..............................36
5.2-4 液晶盒的製作......................................37
第六章 實驗結果與討論..............................................39
6.1 RAS回顧.................................................39
6.2 表面形貌................................................39
6.3 不同摩擦強度下的異向性光譜..............................41
6.4 特徵光譜與摩擦強度的比較................................45
6.5 不同PI所量測到的RAS譜線比較............................47
6.5-1 表面粗糙度與RAS光譜綜合比較......................48
6.6 RAS背面量測.............................................49
6.6-1 實驗動機..........................................49
6.6-2 樣品背面量測結果分析..............................50
6.7 表面能與預傾角的結合....................................51
6.7-1 表面能與液晶分子傾角..............................52
6.7-2 RAS與預傾角.......................................54
第七章 結論與未來工作..............................................56
參考文獻....................................................58

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