臺灣博碩士論文加值系統

探討以原子層沈積法成長二氧化鈦薄膜於矽基板上的物理和化學特性，且利用金氧半結構來分析電特性。此外，利用氮氣和氧氣進行熱退火處理以改善薄膜特性。另一方面，利用以液相沈積法成長二氧化矽薄膜時所產生的氟離子來鈍化二氧化鈦薄膜以進一步的改善漏電流

In this study, the characteristics of atomic layer deposited TiO2 films on silicon substrate were investigated. The physical and chemical properties were measured and surveyed. And an Al/ALD-TiO2/Si MOS structure was used for the electrical characterizations. For the electrical property improvements, we investigated the atomic layer deposited TiO2 films by the post-anneal treatments in nitrogen and oxygen ambient. Furthermore, the TiO2 films were passivated by fluorine ions to decrease the leakage current density that came from the liquid phase deposited SiO2 stacks.
After the post-annealing and fluorine ions passivation treatments, the dielectric constant of atomic layer deposited TiO2 film was maintained and the leakage current density was improved.

Chapter 1 1
Introduction 1
1.1 Developments in gate dielectric 1
1.2 Properties of TiO2 2
1.3 Comparison of deposition methods of TiO2 4
1.4 Advantages of MOCVD 4
1.5 Advantages of ALD 5
1.6 Motivation of Fluorine passivated ALD-TiO2/Si MOS structure 6
References 13
Chapter 2 23
Experiments 23
2.1 CVD theorem 23
2.2 Deposition system of MOCVD 24
2.3 Properties of source materials 25
2.4 Deposition system of ALD 26
2.5 Silicon oxide prepared by LPD 26
2.5.1 Deposition system 26
2.5.2 Mechanisms of LPD-SiO2 27
2.5.3 Preparations of deposition solutions 27
2.6 Deposition procedures 28
2.6.1 Si wafer cleaning procedures 28
2.6.2 Aluminum metal cleaning processes 29
2.6.3 Preparations of MOCVD-TiO2 films 29
2.6.4 Growth Parameters of ALD-TiO2 films 30
2.6.5 Preparations of LPD-SiO2 films 30
2.6.6 Fabrication of Metal-Oxide-Semiconductor Structure 31
2.7 Characterization 31
2.7.1 Physical properties 31
2.7.2 Chemical properties 32
2.7.3 Electrical properties 32
References 50
Chapter 3 51
Results and Discussion 51
3.1 Deposition rate of TiO2 films as a function of deposition temperature 51
3.2 XRD patterns of TiO2 films as a function of deposition temperature 52
3.3 SEM morphologies of TiO2 films as a function of deposition temperature 53
3.4 AFM surface roughness of TiO2 films as a function of deposition temperature 53
3.5 ESCA analyses of TiO2 films as a function of deposition temperatur 54
3.6 Electrical properties of MOCVD-TiO2 films on deposition temperature 55
3.6.1 Leakage current density of MOCVD-TiO2 films as a function od deposition temperature 55
3.6.2 C-V characteristics and dielectric constant of deposition temperature 56
3.6.3 Improvement in electrical properties of as-deposited MOCVD-TiO2 films by annealing treatment 57
3.7 Electrical properties of ALD-TiO2 films on deposition temperature 59
3.7.1 Leakage current density of ALD-TiO2 films as a function of deposition temperature 59
3.7.2 C-V characteristics and dielectric constant of ALD-TiO2 films as a function of deposition temperature 60
3.7.3 Electric Characteristics of ALD-TiO2 Films prepared at different annealing temperature in O2 ambient 61
3.7.4 Improvement in electrical properties of ALD-TiO2 films by annealing treatment 62
3.8 Fluorine passivation of ALD-TiO2/Si MOS structure 63
3.8.1 The leakage current density of LPD-SiO2/ALD-TiO2/Si after LPD-SiO2 removal with varied N2 annealing temperature 64
3.8.2 Mechanisms of leakage current 66
3.8.2.1 Frenkel-Poole plots for as-grown ALD-TiO2 films 66
3.8.2.2 Space-charge limited plots for O2-ammealed ALD-TiO2 films 66
3.8.2.3 Schottky emission plots of LPD-SiO2/O2-annealed ALD-TiO2/Si after LPD-SiO2 removal MOS structure with varied N2 annealing temperature 67
3.8.3 The C-V characteristics of LPD-SiO2/ALD-TiO2/Si after LPD-SiO2 removal with varied N2 annealing temperature 68
References 99
CHAPTER 4 100
Conclusions 100

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