磁性薄膜研究已經是在半導體產業之後最熱門的課題，如何可以找出新的材料使得磁性和電性穩定共存且互相耦合，且薄膜特性穩定並不容易氧化而變質，是現在實驗上所面臨到的考驗。
本研究主要選擇氮化釓（GdN）薄膜為研究主軸，薄膜本身屬於簡單的氯化鈉結構，易於分析，在磁性方面，順磁性轉鐵磁性的居里溫度點，也比其他Gd化合物高，且也具有鐵磁性半金屬性質，在費米能階附近百分之百極化，這種只有單一自旋的概念，可以應用在未來的磁性硬碟或者高精密讀頭，在製成方面，也可以當作自旋過濾器，當薄膜通入雜亂無序的自旋電子，卻只可輸出單一自旋方向的電子。
為了使得GdN薄膜在成長時不與矽基板產生其他化學反應，且可以隔絕外界水氣，所以在濺鍍成長薄膜時，會利用氮化鋁(AlN)當作保護層在成長GdN薄膜之前以及在GdN薄膜上各濺鍍上一層， 這個方法雖然可以有效成長並且保護GdN薄膜，但也因為AlN薄膜原本不導電的特性，造成量測電性時會遇到困難。
為了瞭解薄膜內部的物理特性，實驗上會利用霍爾效應、電阻率和溫度三者的關係去了解薄膜中的載子類型、濃度和遷移率。最後再利用外加偏壓，注入或取出載子來調變內部載子濃度，達到有效控制薄膜的電子結構。

Magnetism has attracted the attention of scientists and engineers from very early times and it is still remained favorite subject due to their vast range of application possibilities. Recently, researchers have been interested in coupling the magnetic and electric order parameters to realize advanced data storage devices, diluted magnetic semiconductors, spintronic devices etc. Magnetic thin film systems have been proved great help for researchers in achieving their goal because thin films have advantage that it can be easily tailored as per requirement with varying parameters like thickness, temperature, ambient pressure. GdN is an intrinsic ferromagnetic material having Curie temperature near 70 K. It supports both p-type and n-type carrier conduction depending on nitrogen vacancies. GdN has tremendous potential for application in spintronic devices. For the sake of in-depth analysis of magnetism, carrier concentration, nature of mobile carriers and mobility, we have investigated the magnetic property, Hall effect, electrical transport property and bias voltage effect on GdN ferromagnetic semiconductor.

論文審定書 i
致謝 ii
摘要 iii
ABSTRACT iv
目錄 v
圖目錄 vii
第一章 緒論 1
第二章 原理與文獻回顧 3
2-1材料的磁性介紹 3
2-1-1反磁性(DIAMAGNETISM) 3
2-1-2順磁性(PARAMAGNETISM) 4
2-1-3鐵磁性(FERROMAGNETISM) 4
2-1-4反鐵磁性(ANTIFERROMAGNETISM) 5
2-2 半金屬(HALF METALS) 6
2-2-1 何謂半金屬 6
2-2-2 半金屬應用 7
第三章 實驗方法與原理及儀器簡介 8
3-1 實驗樣品 8
3-1-1 實驗樣品簡介 8
3-1-2 實驗樣品配置 9
3-2 實驗原理與方法 13
3-2-1 霍爾效應 13
3-2-2 VAN DER PAUW 量測原理 15
3-2-3 量測介紹 19
3-3 實驗儀器簡介 23
3-3-1 低溫量測系統 23
3-3-2雙束行聚焦離子束(FOCUSED ION BEAM) 24
3-3-3電子束蒸鍍系統(ELECTRON-BEAM GUN COATER SYSTEM) 25
3-3-4超導量子干涉震動磁量儀 27
第四章 數據分析與討論 29
4-1導電層電極厚度校正 29
4-2 量測系統校正 31
4-3 霍爾效應(HALL EFFECT)量測 33
4-4 Ρ-T CURVE 39
4-5 加偏壓下的霍爾效應 42
4-5-1 在環境溫度為30K加偏壓下的霍爾效應 43
4-5-2 在環境溫度為40K加偏壓下的霍爾效應 45
4-5-3 在環境溫度為50K加偏壓下的霍爾效應 47
4-5-4 在環境溫度為90K加偏壓下的霍爾效應 49
4-5-4加偏壓下的霍爾效應載子濃度與遷移率變化 51

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