本研究以射頻磁控濺鍍(RF sputtering)的方式，來備製一濕度感測器。並以二氧化鈦作為濕度感測元件之感測材料，最後再利用蒸鍍的方式製作一對指狀型電極以製得所要的感測元件。本文研製出兩種不同結構之濕度感測器元件，包括Al/TiO2/Si (MOS)和TiO2/Al/TiO2/Si (OMOS)，這兩種結構之感測器元件的響應時間分別為120秒和50秒。在本實驗探討的製程參數範圍內，當二氧化鈦薄膜成長於400℃時，其感測器有最小的遲滯現象及最短的反應時間。以LCR meter測試後，溫度於27℃的條件下，濕度從90%RH變化至30%RH回復時間需30秒左右。

In environmental control, humidity detection is very important. In particular, precise humidity detection is necessary in the industry of high technology and manufacturing industries. Therefore, the sensors changed the structure to improve the sensing effect. In this study, the humidity sensors were produced by using the RF sputtering. TiO2 films as sensing membranes of the humidity sensor. Interdigital electrode was produced by thermal evaporation system. This thesis fabricates two kinds of sensor structure devices including Al/TiO2/Si (MOS), TiO2/Al/TiO2/Si (OMOS). The response time for these sensor are 120s and 50s respectively. The TiO2 thin film were prepared at growth temperature of 400℃, it shows improvement to the hysteresis and response time of sensors. The recovery time required about 30 seconds in the range of 90%-30% RH at 27℃.

Contents
摘要 I
Abstract II
Acknowledgement III
Contents IV
List of Table IX
Figure Caption X
Chapter 1 Introduction 1
1.1 Introduction 1
1.2 Research motivation and objectives 4
1.3 Outline of dissertation 5
Chapter 2 Literature review 6
2.1 Introduction of Titanium Dioxide 6
2.2 Applications of titanium dioxide 8
2.3 Materials of humidity sensor 8
2.4 Principle of humidity sensor 10
2.5 Types of humidity sensors 11
2.5.1 Ceramic humidity sensors 11
2.5.2 Polymer humidity sensors 12
2.5.3 Electrolyte humidity sensors 13
Chapter 3 Experiment 14
3.1 Experimental design 14
3.1.1 Experiment flow 14
3.1.2 Substrate cleaning procedures 16
3.1.3 Fabrication of titanium dioxide membrane 16
3.1.4 Preparation of titanium dioxide humidity sensor 17
3.2 Experiment apparatus 20
3.2.1 DC/RF magnetron sputtering 20
3.2.2 Spin coater and exposure system 21
3.2.3 Thermal evaporation system 22
3.3 Measurement apparatus 24
3.3.1 Scanning electron microscope (SEM) and energy dispersive spectrometers (EDS) 24
3.3.2 X-ray diffraction (XRD) 25
3.3.3 Four point probe measurements and Hall measurement system 25
3.3.4 Raman spectrum 26
3.3.5 Atomic force microscope (AFM) 27
3.3.6 Environment test of sensor in system 27
Chapter 4 Results and discussion 29
4.1 Results and analysis of TiO2 thin films 29
4.1.1 X-ray diffraction (XRD) analysis 29
4.1.2 Surface morphology analysis 30
4.1.3 Energy dispersive spectrometers (EDS) analysis 35
4.1.4 TiO2 layer analysis for Raman spectrum 37
4.1.5 Atomic force microscope (AFM) analysis 38
4.1.6 Al/TiO2/Si structure of the humidity sensing characteristics 38
4.2 Analysis of double layer TiO2 films 42
4.2.1 X-ray diffraction (XRD) analysis 42
4.2.2 Surface morphology analysis 43
4.2.3 Energy dispersive spectrometers (EDS) analysis 44
4.2.4 Raman spectrum system analysis 44
4.2.5 TiO2/Al/TiO2/Si structure of the humidity sensing characteristics 46
4.3 TiO2 humidity sensing device 47
4.3.1 Resistance measurement 47
4.3.2 Capacitance measurement 51
4.3.3 Inductance measurement 54
Chapter 5 Conclusions 57
References 58
Publication List 62
中文目錄
摘要 63
第一章 介紹 64
第二章 文獻回顧 65
第三章 實驗方法 66
第四章 結果與討論 67
第五章 結論 68

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