臺灣博碩士論文加值系統

在本研究中，我們探討一種通過拉曼光譜分析磊晶GaN晶體質量的方法，並且通過在藍寶石基板上添加一層 AlN 薄膜改善AlGaN/GaN HEMT 的元件性能。結果顯示，元件崩潰電壓從15.2 V提升至27.4 V，而HEMT 元件的最大汲極電流為521 mA/mm，與未添加AlN薄膜的元件相比增加了10%。

In this study, a method of analyzing the crystal quality of epitaxial GaN by Raman spectroscopy was established. By adding an AlN thin film on sapphire substrate, the device performance of the AlGaN/GaN HEMT was improved. The breakdown voltage was increased from 15.2 V to 27.4 V, and the maximum drain current of the HEMT device were 521 mA/mm, increased by 10% compared with the device without AlN.

English Abstract........................................................i
Chinese Abstract......................................................ii
Acknowledgements or Preface................................iii
Table of Contents.....................................................iv
List of Tables............................................................v
List of Figures..........................................................vi
Symbols...................................................................vii
Chapter 1 Introduction.............................................1
1.1 Preface..............................................................1
1.2 Motivation..........................................................2
Chapter 2 Theoretical Basis....................................4
2.1 Sapphire substrate............................................4
2.2 Gallium Nitride...................................................5
2.3 AlGaN/GaN Heterojunction................................7
2.3.1 Polarization Effect...........................................7
2.3.2 Two-Dimensional Electron Gas.......................11
2.4 Aluminum Nitride................................................11
2.5 Raman Spectroscopy.........................................12
Chapter 3 Laboratory Equipment and Device Fabrication...14
3.1 Process Equipment............................................14
3.1.1 Photolithography.............................................14
3.1.2 Electron Beam Lithography.............................15
3.1.3 Electron Beam Evaporator..............................15
3.1.4 Rapid Thermal Process...................................16
3.1.5 RIE..................................................................17
3.1.6 ICP-RIE...........................................................17
3.1.7 PECVD............................................................18
3.2 Measurement Method........................................18
3.2.1 Micro-Raman Spectrometer............................18
3.2.2 TLM Measurement..........................................19
3.2.3 Hall Measurement...........................................20
3.3 Device Fabrication..............................................20
Chapter 4 Experiments and Results.............................22
4.1 Crystal Quality and Raman Spectroscopy..............22
4.2 TLM measurement and DC characteristics of devices...24
Chapter 5 Conclusion...................................................27
Reference.....................................................................28
Extended Abstract

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