臺灣博碩士論文加值系統

本論文利用金屬有機物化學氣相沉積系統成長P型氮化鎵/氮化鋁鎵，分析其飽和濃度、表面析出物、活化率、與鎂原子的擴散。
透過調變二茂鎂流量，隨著流量增加，發光機制逐漸被深層施子與受子對復合發光主導，深層施子缺陷（VN）的螢光也逐漸增強。另外，拉曼光譜顯示樣品隨流量增加壓縮遞減而逐漸往伸張應力偏移。當鎂逐漸在表面析出時，可以推論摻雜濃度應趨近於飽和，霍爾量測得出450 sccm的樣品之鎂活化率達2.22%最大值，比一般文獻報導的1%高，且電洞濃度沒有發生反轉，由於成長的結構設計與存在應力有關。
在P型氮化鎵/氮化鋁鎵介面之間使用氮化鋁插入層，發現即使在摻雜濃度達飽和的情況下，同樣可以提升活化率且有效阻擋鎂原子擴散，因為插入氮化鋁層影響應力分佈而降低擴散。從低溫光譜與拉曼的結果也證實了氮化鋁插入層使P型氮化鎵呈些微壓縮應力，並減少氮空缺形成。

In this thesis, the metal organic chemical vapor deposition system is used to grow p-GaN/AlGaN. The saturation concentration, morphology, activation rate, and diffusion of magnesium atoms are analyzed.
By modulating the flow rate of Cp2Mg, the luminescence mechanism was gradually dominated by the deep donor-acceptor pair (DAP) recombination when the flow rate increases. The emission intensity of the deep donor-related defects (VN) was strongly enhanced. Raman spectroscopy shows that the sample gradually shifts from the compressive strain to the tensile stress as the flow rate increases. The saturation of p-type doping can be inferred by the segregation of magnesium on the sample surface. The Hall measurement showed that the activation rate of the 450 sccm sample reached a maximum value of 2.22%, which is higher than 1% reported in the literature. There was no hole concentration reverse observed due to the structure design and existence of stress.
By using an AlN interlayer at the interface of p-GaN/AlGaN, the activation rate can also be improved when the doping concentration reaches saturation, and the diffusion of magnesium atoms can be effectively suppressed. It is due to the existence of AlN interlayer affects the stress distribution and further suppress the diffusion. The photoluminescence (PL) and Raman measurements also confirmed that the existence of AlN interlayer results in a slight compressive stress in the p-GaN and further reduces the formation of nitrogen vacancies.

摘要 i
Abstract ii
致謝 iv
目錄 v
表目錄 vii
圖目錄 viii

第一章 緒論 1
1.1氮化鎵(GaN)材料簡介與發展 1
1.2鎂摻雜氮化鎵(p-GaN)材料簡介 3
1.3鎂摻雜氮化鎵(p-GaN)在HEMT上的應用與發展 5
1.4研究動機 8

第二章 樣品結構與實驗儀器原理 10
2.1樣品結構與參數 10
2.2量測儀器及原理 12
2.2.1光激螢光光譜(Photoluminescence Spectroscopy) 12
2.2.2拉曼光譜(Raman Spectroscopy) 15
2.2.3掃描式電子顯微鏡(Scanning Electron Microscope, SEM) 17
2.2.4能量色散X-射線光譜(Energy dispersive X-ray spectrometer, EDS) 19
2.2.5原子力顯微鏡(Atomic Force Microscope, AFM) 20
2.2.6二次離子質譜儀(Secondary Ion Mass Spectrometer, SIMS) 21
2.2.7霍爾量測(Hall measurement) 22

第三章 結果與討論 24
3.1不同鎂流量與光性、表面形貌、電性之關係 24
3.1.1低溫（10K）光激螢光光譜與鎂流量之關係 24
3.1.2拉曼光譜與鎂流量之關係 30
3.1.3表面形貌量測結果與分析 34
3.1.4電性量測結果與分析 40
3.1.5第一系列樣品量測分析小結 45
3.2引入插入層與光性、表面形貌、電性之關係 46
3.2.1電性量測結果與分析 46
3.2.2表面形貌量測結果與分析 52
3.2.3引入插入層之低溫（10K）光激螢光光譜分析 53
3.2.4引入插入層之拉曼光譜分析 55
3.2.5第二系列樣品量測分析小結 57

第四章 結論 58

參考文獻 59

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