臺灣博碩士論文加值系統

非接觸式配向因可解決刷磨式配向所帶來的污染問題而受到產學界之重視。本論文乃以新興技術電漿束液晶配向來製作LCD配向膜，研究中藉由實驗設計法之應用、PI膜材特性量測及液晶Cell光學量測三者的交叉比對討論來獲得電漿製程參數與液晶配向的關係。

有鑑於電漿束配向製程實屬複雜之程序且電漿製程參數種類繁多，因此本研究應用實驗設計法探討電漿製程參數對其配向膜材特性與液晶光電量測 (預傾角)之影響情形。由於配向膜材為PI膜，實屬有機化合物，因此對配向膜材作物理性轟擊及化學性反應的討論，從結果中發現進料氣氛為本研究選定討論製程參數影響目標函數最顯著的因子。

從物理性轟擊討論，當進料氣氛為純Ar時，經由膜厚量測儀、AFM量測、蝕刻速率及電流密度量測發現所擁有的離子轟擊力是比其他組實驗大；從化學性反應討論，經由ESCA量測及接觸角量測，當進料氣氛為純Ar時接觸角較大、氧碳比較小，所代表的訊息是疏水性較佳。總結，電漿束離子配向轟擊PI膜確實會造成順序性的溝槽，雖然工作電壓加大，會加速腔體內的反應；轟擊時間越長，累積能量越大，不過以上兩項製程參數對於溝槽的大小及薄膜表面親疏水性影響並不大，對於液晶預傾角影響也不顯著，當轟擊時間越長的話，並未得到較大的預傾角。所以控制液晶預傾角最直接的方法就是控制進料氣氛，再搭配適中的轟擊時間，即可有效的控管液晶預傾角。


關鍵詞：非接觸式配向、電漿束液晶配向、預傾角、實驗設計法

Abstract
Non-contacting alignment technology has attracted much attention of the academia and industry for the last decade due to pollutant problem related to the alignment method by brushing and rubbing. This study dealt with the liquid crystal display (LCD) alignment layer, developed by advanced plasma beam LC alignment technology. In this study, experimental design methodology, polyimide (PI) films characteristic, and LC cell measurement were used to investigate the relationships among the plasma processing parameters and the LC alignment.
As a result of the complexity involved in the processing of the plasma beam alignment and the diversity of the parameters associated with the plasma processing, this study used the methodology of experimental designs to evaluate the impact of these parameters on the characteristics of the PI films and the LC pretile angles for the opto-electronic measurements. Since the PI films for alignment were organic compounds, their physical bombardment and chemical properties were investigated. The results of this study indicated that the gas ratio of hydrogen to argon was the most prominent factor affecting the process parameters.
From the ion bombardment view point, as the gas environment to be pure argon, the force resulting from the ion bombardment was found to be larger than the other cases using the measurements of the film thickness, force by atomic force microscopy (AFM), itching rate, and current density. From the chemical reaction view point, the contact angle was larger and the ratio of oxygen to carbon was smaller for the case with pure argon, as measured by the Electron Spectroscopy for Chemical Analyzer (ESCA) and by the Contact Angle Analyzer. This revealed that this case is hydrophobia. In summary, PI films were aligned by plasma ion beam bombardment indeed resulted in sequential grooving of the films. Even though an increase in the applied voltage led to the reaction inside the chamber, the longer the bombardment time, the higher it was for the accumulated energy. Nevertheless, the impact of the process parameters on the width of the groove and on the wettability of the film surface was not large. Its impact on the LC pretilt angle was not obvious either. The pretilt angle did not seem to be larger by prolonging the bombardment time. Therefore, it was concluded that the most direct means for controlling the LC pretilt angle was to control the gas ratio of hydrogen to argon, together with adequate bombardment time.

Keywords: Non-contacting alignment, Plasma beam alignment, Pretilt angle,
Experimental designs

目 錄

摘 要……………………………………………………Ⅰ
英文摘要………………………………………………………………Ⅱ
誌 謝…………………………………………………………………Ⅳ
目 錄…………………………………………………………………Ⅴ
表目錄…………………………………………………………………Ⅷ
圖目錄………………………………………………………………Ⅸ


第一章 前言………………………………….………………………1

1-1研究動機……………...….…………………………1
1-2 研究目的及架構…….………………………………...2

第二章 基礎理論及文獻回故………………………………………5

2-1電漿原理……………………………………………5
2-1-1 電漿現象……………...…………...…………………...5
2-1-2 電漿生成反應…………...…………………………..…7
2-1-3 電漿放電形式………………..……………………….10
2-1-4 電漿的應用…………..…………………………….....12
2-1-5 電漿蝕刻……………..……………………………….13

2-2 液晶配向原理………………………………………15
2-2-1 液晶的簡介及基本特性……..…………...……….…15
2-2-2 配向膜原理……………………………...……………17
2-2-3 配向機制………….………………………..…………20
2-2-4 電漿束配向技術….………………………..…………26
2-2-5 配向技術的比較.…………………………..…………28

2-3 實驗設計法….…………..………………………………29
2-3-1 反應曲面法……….………………………..…………29






第三章 實驗量測分析儀器及研究方法………...…………………33

3-1 試片製作…………………………………………...33
3-1-1 試片清潔……….………………………..…………33
3-1-2 配向膜塗佈…….………………………..…………34
3-1-3 保存…………….………………………..…………34

3-2 實驗儀器…………………………………………….35
3-2-1 ALT電漿束配向製程機台…………..…………35

3-3 Cell組裝………..………………………………….37
3-3-1 試片貼合………………………………...………37
3-3-2 灌入液晶…………………………...……………38

3-4 分析儀器.……….………………………………...39
3-4-1 原子力顯微鏡…………………………...………39
3-4-2膜厚量測儀………………………...……………41
3-4-3預傾角量測系統…………………...……………42
3-4-4電子能譜化學分析儀……………...……………44
3-4-5接觸角量測系統…………………...……………46
3-4-6偏光顯微鏡………………….……...……………47

第四章 結果與討論…………………………………………………48

4-1 膜厚變化及蝕刻速率………………..……………………48
4-1-1 Current Density………………………...………59

4-2表面粗糙度………………………………………………62

4-3表面親疏水特性…………………………………………71
4-3-1電子能譜化學分析儀量測………………………71
4-3-2接觸角量測……………….………………………77

4-4液晶預傾角量測…………………………………………83

4-5偏光顯微鏡量測…………………………………………88

4-6 PI膜檢測與液晶預傾角綜合討論……………………89

4-6-1物理性轟擊…………………….…………………89
4-6-2化學性反應……………….………………………90

第五章 結論與未來展望…………………………………….……92


參考文獻…..…………………………………………………………… 94

附錄A 十五組實驗AFM量測影像………………...………………99
附錄B 十五組實驗接觸角量測影像…………….…………..……103
附錄C 十五組配向實驗後液晶Cell影像….……………….……107
附錄D 十五組實驗偏光顯微鏡量測影像….………………..……122





表目錄

表.2-1各類配向技術比較表……………………………………28
表.4-1實驗設計製程參數對照表………………………………49
表.4-2膜厚變化及蝕刻速率實驗參數…………………………50
表.4-3製程參數對膜厚變化迴歸模式契合度之比較…………54
表.4-4製程參數對蝕刻速率迴歸模式契合度之比較…………58
表.4-5電流密度實驗參數表…………………….………………60
表.4-6表面粗糙均方根值實驗參數….…………………………63
表.4-7氧碳比實驗參數表………………….……………………72
表.4-8製程參數對氧碳比迴歸模式契合度之比較表…………75
表.4-9接觸角實驗參數表………………………….……………78
表.4-10液晶欲傾角實驗參數表………………………….……………85
表.4-11製程參數對液晶欲傾角迴歸模式契合度之比….……………87


圖目錄

圖.1-1研究架構示意圖…………………………………………………4
圖.2-1低壓電漿反應器內電壓電流關係…….………………………..10
圖.2-2水溶液蝕刻出的溝槽…………………..………………………13
圖.2-3電漿蝕刻出的溝槽…….………………….……………………13
圖.2-4電漿蝕刻示意圖…….…………………….……………………14
圖.2-5固態、液晶態及液態的分子排列…….…….…………………15
圖.2-6液晶三種型態的排列結構圖…….……….……………………16
圖.2-7液晶螢幕橫面簡圖……………………………..………………17
圖.2-8 Pretilt angle 示意圖………………….………………………18
圖.2-9液晶驅動示意圖………………………..………………………20
圖.2-10斜向鍍膜示意圖…….………………………....………………21
圖.2-11刷磨式配向 (Rubbing) 示意圖……….………………………22
圖.2-12刷磨後液晶分子排列示意圖…….……………………………22
圖.2-13光配向示意圖………………………….………………………23
圖.2-14 Kaufman-Type 離子槍…….…………….……………………24
圖.2-15 Kaufman-Type Ion Source 示意圖…….……………………25
圖.2-16離子束配向法示意圖…….……………………………………25
圖.2-17電漿束配向法示意圖…….……………………………………27
圖.2-18 ALT幾何示意圖…….…………………...……………………27
圖.2-19最小平方法示意圖…….………………………………………31
圖.3-1 ALT電漿束配向製程機台示意圖.………………………36
圖.3-2 Cell膠封示意圖………………………..…………………37
圖.3-3原子力顯微鏡 (AFM)原理圖…….………………………40
圖.3-4 AFM針尖放大圖…….……………….……………………40
圖.3-5膜厚量測儀示意圖………………………………………41
圖.3-6入射光在晶體內路徑示意圖……………………………42
圖.3-7預傾角量測系統示意圖……….….………………………43
圖.3-8電子能譜化學分析儀(ESCA)結構示意圖………………45
圖.3-9接觸角量測結果圖例…….………………………………46
圖.3-10偏光顯微鏡量測結果圖例…….………………………………47
圖.4-1製程參數對膜厚變化迴歸模式之預測曲線圖……...……52
圖.4-2膜厚變化數據與迴歸分析預測數據比較圖………...……55
圖.4-3工作電壓與轟擊時間交互關係對膜厚變化的曲線圖.……56
圖.4-4製程參數對蝕刻速率迴歸模式之預測曲線圖……...……57
圖.4-5製程參數對電流密度迴歸模式之預測曲線圖……...……61
圖.4-6製程參數對表面粗糙均方根迴歸模式之預測曲線圖……64
圖.4-7-1第1組製程參數AFM 3-D影像………………………..……65
圖.4-7-2第1組製程參數AFM 2-D影像………………………..……65
圖.4-8-1第2組製程參數AFM 3-D影像………………………..……66
圖.4-8-2第2組製程參數AFM 2-D影像………………………..……66
圖.4-9-1第9組製程參數AFM 3-D影像………………………..……67
圖.4-9-2第9組製程參數AFM 2-D影像………………………..……67
圖.4-10-1第11組製程參數AFM 3-D影像…..…………………..……68
圖.4-10-2第11組製程參數AFM 2-D影像……..………………..……68
圖.4-11-1未經過配向AFM 3-D影像…..……….………………..……69
圖.4-11-2未經過配向AFM 2-D影像…………..………………..……69
圖.4-12-1經過配向(第5組實驗)AFM 3-D影像….……………..……70
圖.4-12-2經過配向(第5組實驗)AFM 2-D影像……..…….…..……70
圖.4-13製程參數對氧碳比迴歸模式之預測曲線圖……..….…..……73
圖.4-14工作電壓與進料氣氛交互關係對氧碳比的曲線圖…….……76
圖.4-15轟擊時間與進料氣氛交互關係對氧碳比的曲線圖…….……76
圖.4-16製程參數對接觸角迴歸模式之預測曲線圖……..….…..……79
圖.4-17第3組製程參數接觸角影像……..……………….....…..……80
圖.4-18第4組製程參數接觸角影像……..……………….....…..……80
圖.4-19第10組製程參數接觸角影像……..……..……….....…..……81
圖.4-20第12組製程參數接觸角影像……..…………...….....…..……81
圖.4-21未經過配向接觸角影像…………..……………….....…..……82
圖.4-22製程參數對液晶欲傾角迴歸模式之預測曲線圖…...…..……86

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