臺灣博碩士論文加值系統

在本篇論文當中，我們利用薄膜形貌工法技術的概念製作出一個以氧化鋅當做通道的單極性反相器。此反相器的通道尺寸為次微米等級且只需四道光罩即可完成，並在操作電壓為十五伏特時，達到極大的電壓增益值一百二十。除此之外，我們探討了兩種不同閘極介電層所呈現出來不同的遲滯效應，並且解決負遲滯效應所產生的電路應用問題。另外，為了進一步設計環形震盪器，我們對此反相器進行切換速度的分析。根據量測結果，必須找到能同時兼顧直流與交流特性的製程條件。透過分析與實驗之後，我們提出了解決的辦法並加以驗證。

In this thesis, we use the novel film-profile engineered (FPE) TFTs structure to fabricate and demonstrate high-performance ZnO unipolar inverters. The ZnO FPE inverters with submicron channel lengths only need four masks and show a high voltage gain of 120 at VDD=15V. Besides, we also explore the root causes of hysteresis mechanism which is related to the use of gate dielectrics. We also explore the AC characteristics of FPE inverters. Based on the measurement result, trade-off between DC and AC characteristics is identified a crucial factor for circuit application. Through analysis and experiment, we proposed a solution which is able to enhance both AC and DC characteristics.

Contents
摘要 i
Abstract ii
Acknowledgment iii
Contents iv
Table captions vi
Figure captions vii
Chapter 1 Introduction 1
1-1. Back-end-of-line metal oxide thin film transistors 1
1-2. Properties of zinc-oxide (ZnO) films 3
1-3. Film profile engineered (FPE) TFTs 5
1-4. N-type unipolar inverters 6
1-5. Motivation and objectives 9
1-6. Organization of the thesis 10
Chapter 2 Device fabrication and measurement setup 12
2-1. Process flow of the ZnO FPE inverters 12
2-2. The measurement setup 14
2-3. Data measurements and parameter extraction 15
2-4. Results and discussion of the first-version inverters 18
Chapter 3 Results and discussion 21
3-1. Effects of gate dielectric on the characteristics of inverters 21
3.1.1 Electrical characteristics of FPE inverters with different gate dielectrics 21
3.1.2 The hysteresis mechanism on FPE transistors 23
3-2. The AC characteristics of different gate dielectrics on inverters 28
3-3. Effects of metal pad materials on FPE TFTs 30
3.3.1 Electrical characteristics of the FPE TFTs 30
3.3.2 Extraction of series resistance of FPE TFTs with different metal pad materials 31
Chapter 4 Conclusion and future work 33
4-1. Conclusion 33
4-2. Future work 34
References 35
Tables 41
Figures 42
Vita 70

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