隨著顯示器逐漸增大，其電阻、寄生電容所造成時間延遲的現象，將會變的更加顯著。而使用高介電值材料在薄膜電晶體上，可以提高閘極氧化層的電容值，以獲得一個較高的汲極電流來解決面板變大所造成的問題，並且可增加面板的開口率。
在本實驗中，我們利用液相沉積法(LPD)在非晶矽及多晶矽基板上成長鈦矽氧化薄膜，並在成長溶液中加入氨水來控制PH值及防止HF的過度蝕刻。
在物性與化性方面，我們利用掃描式電子顯微(SEM)、反射式光譜儀、傅立葉紅外線光譜儀(FTIR)與X光繞射儀(XRD)分析，並製作MOS之電容結構以量測其介電特性，並針對鈦矽氧化膜之漏電流密度與介電常數等與製程參數之關係加以研究探討。此外，在經由氧氣與氮氣回火處理後漏電流也有顯著的改善。然而，在金屬化熱處理後，可以再更進一步地改善電性。
金屬化熱處理是一種利用氧化層表面的氫氧根(OH-)和披覆金屬層(Al)反應而產生活性氫原子，此活性氫原子可擴散進入到鈦矽氧化膜裡，進而鈍化膜裡的缺陷及懸鍵。因此，可在維持高介電常數的條件下降低漏電流。

When the size of display panel increased, the RC delay of TFTs became serious.In order to solve this problem, it is necessary to incorporate a high dielectric (high-k) material used as the gate oxide can increase the gate oxide capacitance Co, which can induce a higher drain current and higher aperture ratio.
In this study, titanium silicon oxide films were grown on amorphous silicon and poly-crystal silicon by liquid phase deposition, the addition of NH4OH in the growth solution can control the PH value and prevent the amorphous and poly-crystalline silicon over etching by HF.
The physical and chemical properties of titanium silicon oxide film by means of several measuring instruments, including Fourier transform infrared spectrometer (FTIR), and X-Ray diffractometer (XRD). An Al/titanium silicon oxide/a-Si or poly-Si/Si metal-oxide-semiconductor (MOS) capacitor structure was used for the electrical measurements. After oxygen and nitrogen annealing, the leakage current is improved due to the reduction of the oxygen vacancy of titanium silicon oxide film. However, the electrical characteristics can be further improved by the postmetallization annealing treatment especially under the negative electric field.
Post-metallization annealing (PMA) is to use the reaction between the aluminum contact and hydroxyl groups existed on oxide surface to form active hydrogen and diffuse through the oxide to passivate the oxide traps. Therefore, titanium silicon oxide
film which treated by PMA with higher dielectric constant and lower leakage current can be obtained.

CONTENTS
ACKNOWLEDGMENT..........................................................I
ABSTRACT............................................................................II
LIST OF FIGURES ...........................................................VIII
LIST OF TABLES................................................................XII
CHAPTER1 1
INTRODUCTION 1
1-1 Background 1
1-2 Liquid Crystal Drive Schemes 2
1-2-1 PassiveMatrix 2
1-2-2 Active Matrix 3
1-3 Comparison between a-Si and poly-Si TFT 3
1-4 Development of a-Si and poly-Si TFT 4
1-5 High Dielectric Constant Materials 5
1-6 Various Techniques for TixSi(1-x)O Film Preparation 6
1-7 Advantages of Liquid Phase Deposition 7
REFERENCES 12
CHAPTER2 16
EXPERIMENT 16
2-1 Deposition System 16
2-2 Cleaning of Silicon Substrate 17
2-3 Preparation of Deposition Solution 18
2-4 Film Deposition 19
2-5 Growth Mechanisms of LPD-TixSi(1-x)Oy Films 20
2-6 Improvements of Electrical Properties 21
2-6-1 Annealing LPD-TixSi(1-x)Oy Films in N2 and O2 Ambient 21
2-6-2 Motivation of TixSi(1-x)Oy/a-Si/Si and TixSi(1-x)Oy/poly-Si/Si 22
2-6-2.1 Aluminum Metal Cleaning Processes 22
2-6-2.2 PMA Procedure 22
2-6-3 Improvement of J-E Characteristics of LPD-TixSi(1-x)Oy Films on poly-Si and a-Si with a SiO2 Buffer Layer 23
2-7 Characteristics 24
2-7-1 Physical Properties 24
2-7-2 Chemical Properties 24
2-7-3 Electrical Properties24
REFERENCES 32
CHAPTER3 33
RESULTS AND DISCUSSION 33
PART I: LPD-TixSi(1-x)Oy Films on a-Si/p-type substrate 34
3-1 Characteristics of LPD-TixSi(1-x)Oy Films on a-Si with Increase Volume of NH4OH 34
3-2 Characteristics of LPD-TixSi(1-x)Oy Films on a-Si with Decrease Volume of H3BO3 35
3-2-1 FE-SEM Views of LPD-TixSi(1-x)Oy Films on a-Si 36
3-2-2 Thickness of LPD-TixSi(1-x)Oy Films on a-Si as a Function of Deposition Time 37
3-2-3 ESCA Analysis of LPD-TixSi(1-x)Oy Film on a-Si 38
3-3 Improvements of Electrical Properties on a-Si 38
3-3-1 Annealing LPD-TixSi(1-x)Oy films in N2 and O2 ambient on a-Si 39
3-3-1.1 X-ray Diffraction Pattern of LPD-TixSi(1-x)Oy Films on a-Si by Annealing in N2 Ambient 39
3-3-1.2 J-E & C-V Characteristics of LPD-TixSi(1-x)Oy films on a-Si 40
3-3-1.3 FTIR Spectra of O2-annealed Thin Films on a-Si 41
3-3-1.4 XPS Spectra of as-grown and N2-annealed of LPD-TixSi(1-x)Oy Films on a-Si 42
3-3-2 Characteristics of LPD-TixSi(1-x)Oy films on a-Si by Post-metallization Annealing (PMA) 43
3-3-2.1 Motivation of TixSi(1-x)Oy/a-Si/Si with PMA Treatment 43
3-3-2.2 J-E & C-V Characteristics of PMA Temperature on a-Si 45
3-3-3 Improvement of J-E Characteristics of LPD-TixSi(1-x)Oy Films on a-Si with a SiO2 BufferLayer 46
PART II: LPD-TixSi(1-x)Oy films on poly-Si/p-type substrate 47
3-4 Characteristics of LPD-TixSi(1-x)Oy Films on poly-Si with Increase Volume of NH4OH 47
3-5 Characteristics of LPD-TixSi(1-x)Oy Films on poly-Si with Decrease Volume of H3BO3 48
3-5-1 FE-SEM Views of LPD-TixSi(1-x)Oy Films on poly-Si 49
3-5-2 Thickness of LPD-TixSi(1-x)Oy Films on poly-Si as a Function of Deposition Time 50
3-5-3 ESCA Analysis of LPD-TixSi(1-x)Oy Film on poly-Si 50
3-6 Improvements of Electrical Properties on poly-Si 51
3-6-1 Annealing LPD-TixSi(1-x)Oy films in N2 and O2 Ambient on poly-Si 51
3-6-1.1 X-ray Diffraction Pattern of LPD-TixSi(1-x)Oy Films on poly-Si by Annealing in N2 Ambient 52
3-6-1.2 SIMS Depth Profile of LPD-TixSi(1-x)Oy Film on poly-Si 52
3-6-1.3 J-E & C-V Characteristics of LPD-TixSi(1-x)O films on poly-Si 53
3-6-1.4 FTIR Spectra of O2-annealed Thin Films on poly-Si 54
3-6-2 C-V & J-E Characteristics of PMA Temperature on poly-Si 55
3-6-3 Improvement of J-E Characteristics of LPD-TixSi(1-x)Oy Films on poly-Si with a SiO2 Buffer Layer 56
REFERENCES 96
CHAPTER 4 100
CONCLUSIONS 100

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