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以作者查詢圖書館館藏 、以作者查詢臺灣博碩士 、以作者查詢全國書目 、勘誤回報 、線上人數：29 、訪客IP：3.21.158.147
姓名 陳逸弘(Yi-Hong Chen) 查詢紙本館藏 畢業系所 電機工程學系 論文名稱 利用石墨烯改善氮化鎵歐姆接觸之研究
(Improved Ohmic Contact on Gallium Nitride by Graphene Layer)相關論文 檔案 [Endnote RIS 格式]
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摘要(中) 本論文主要針對氮化鋁鎵歐姆接觸進行研究，分別對石墨烯特性及挖槽式歐姆接觸進行討論。研究包含，石墨烯轉印流程，並以拉曼光譜分析在不同表面處裡及退火溫度，對石墨烯所造成的影響，並利用傳輸線模型分析加入石墨烯後，接面等效能障的變化。最後綜合石墨烯及挖槽式歐姆接觸氮化鋁鎵/氮化鎵之高電子遷移率電晶體元件，分析其直流電性及接觸電阻的改善。
石墨烯表面經氧電漿處理後，有助於提升後續金屬電極的附著度，實驗觀察到，在短暫的氧電漿處理後，石墨烯的親水度有著明顯的上升，但在拉曼光譜分析中，也觀察到氧電漿處理後，石墨烯缺陷的增加。本研究也探討了300 ℃至850 ℃退火溫度對石墨烯所帶來的衝擊，經由拉曼光譜分析，在氮氣環境下，因為溫度所導致的缺陷增加，發生在400 ℃至500 ℃之間。
傳統氮化鋁鎵/氮化鎵之高電子遷移率電晶體，多使用高溫退火，來形成較好的歐姆接觸，而傳統式特徵歐姆接電阻(Specific contact resistivity, ρc)為7.3×10-5 Ω·cm2，在歐姆接觸區域引入石墨烯插入層，可有效使其特徵歐姆接觸電阻下降至8.1×10-6 Ω·cm2。經傳輸線模型分析、擬合後觀察，電子在熱離子場發射(Thermionic field emission, TFE)模型中，接面等效能障由傳統式歐姆接觸的1.02 eV，下降至有石墨烯插入層歐姆接觸的0.83 eV，解釋了其接觸電阻下降的成因。
挖槽式歐姆接觸也是一個已被實證，有效降低歐姆接觸電阻的方式，本研究加入並聯的長方形挖槽(2×48 μm2)，並在引入石墨烯插入層，有效的降低了接觸電阻至1.36 Ω·mm，相較傳統式歐姆接觸的4.13 Ω·mm，有著67.1 %的下降。並在製程中加入氧電漿處理，有效的去除了石墨烯所導致的額外電流路徑，使得元件能夠達到良好的開關特性。摘要(英) This thesis primarily focuses on the study of gallium nitride ohmic contacts, discussing the characteristics of graphene and recessed ohmic contacts. The research includes the graphene transfer process and analyzes the effects of different surface treatments and annealing temperatures on graphene using Raman spectroscopy. Additionally, the changes in interface barrier height are examined by employing a transfer length method after inserting a graphene layer. Finally, the combined graphene and recessed ohmic contact AlGaN/GaN HEMT are analyzed for their DC electrical properties and contact resistance improvement.
After oxygen plasma treatment on the graphene surface, the adhesion of metal electrodes is enhanced. Experimental observations reveal a significant increase in graphene′s hydrophilicity after a brief oxygen plasma treatment. However, the Raman spectroscopy analysis shows increased defects following the oxygen plasma treatment. This study also investigates the impact of annealing temperatures ranging from 300 °C to 850 °C on graphene. Through Raman spectroscopy analysis in a nitrogen environment, the temperature-induced defect increase is observed to occur between 400 °C and 500 °C.
Conventional high-electron-mobility transistors based on gallium nitride typically undergo high-temperature annealing to form better ohmic contacts. The specific contact resistivity (ρc) of the conventional specific ohmic contact is 7.3×10-5 Ω·cm2. Introducing graphene into the ohmic contact region can effectively reduce its specific contact resistivity to 8.1×10-6 Ω·cm2. Through transfer length method analysis and fitting observations, the interface barrier height in the thermionic field emission (TFE) model is reduced from 1.02 eV for the traditional ohmic contact to 0.83 eV for graphene insert layer ohmic contacts, explaining the decrease in contact resistance.
Recessed ohmic contacts have also been proven to be an effective method for reducing ohmic contact resistance. In this study, 2×48 μm2 rectangular recesses are introduced, and graphene insert layer, effectively reducing the contact resistance to 1.36 Ω·mm. Compared to the traditional ohmic contact resistance of 4.13 Ω·mm, this represents a 67.1% reduction. Furthermore, introducing oxygen plasma treatment during fabrication effectively removes the additional current paths caused by graphene, allowing the device to achieve good on/off characteristics.關鍵字(中) ★ 氮化鎵
★ 石墨烯關鍵字(英) ★ GaN
★ Graphene論文目次 摘要..........................................................................................................................................VI
Abstract................................................................................................................................. VII
致謝.......................................................................................................................................VIII
圖目錄......................................................................................................................................XI
表目錄...................................................................................................................................XIV
第一章 緒論.......................................................................................................................... 1
1.1 前言 ......................................................................................................................... 1
1.2 氮化鎵材料特性 ..................................................................................................... 2
1.3 氮化鎵電晶體歐姆接觸發展概況 ......................................................................... 3
1.3.1 傳統式歐姆接觸........................................................................................................... 4
1.3.2 離子佈植式歐姆接觸................................................................................................... 5
1.3.3 挖槽式歐姆接觸........................................................................................................... 6
1.3.4 低溫退火歐姆接觸..................................................................................................... 10
1.4 研究動機與目的 ................................................................................................... 12
1.5 論文架構 ............................................................................................................... 12
第二章 氮化鎵接觸電阻特性分析.................................................................................... 13
2.1 AlGaN/GaN 磊晶片結構及特性量測................................................................... 13
2.1.1 AlGaN/GaN HEMT 磊晶片......................................................................................... 13
2.1.2 傳輸線模型................................................................................................................. 14
2.2 石墨烯轉印品質與基本電性研究分析 ............................................................... 15
2.2.1 乾式轉印石墨烯流程................................................................................................. 15
2.2.2 拉曼光譜分析............................................................................................................. 16
2.2.3 石墨烯表面處理影響分析......................................................................................... 16
X
2.2.4 溫度對石墨烯影響分析............................................................................................. 21
2.2.5 石墨烯電流路徑分析................................................................................................. 22
2.3 石墨烯對接觸電阻影響之分析 ........................................................................... 25
2.3.1 不同表面處理對接觸電阻之影響............................................................................. 25
2.3.2 歐姆接觸接面等效能障與離子參雜濃度擬合......................................................... 27
2.4 結論 ....................................................................................................................... 33
第三章石墨烯應用在挖槽式歐姆接觸氮化鎵電晶體元件製作與電性分析.................. 34
3.1 挖槽式石墨烯歐姆接觸電晶體佈局 ................................................................... 34
3.2 元件製作流程 ....................................................................................................... 36
3.3 挖槽式石墨烯歐姆接觸之氮化鎵高電子遷移率電晶體電性量測分析 ........... 39
3.4 結論 ....................................................................................................................... 42
第四章 結論........................................................................................................................ 43
參考文獻.................................................................................................................................. 44
附錄Ⅰ 石墨烯乾式轉印製程流程........................................................................................ 47
附錄Ⅱ 元件製程流程............................................................................................................ 48
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n-type GaN,” Journal of Applied Physics, vol. 100, no. 12, 2006.指導教授 辛裕明(Yue-Ming Hsin) 審核日期 2023-8-16 推文 plurk
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