共濺鍍透明電極與N型氮化鎵歐姆接觸及其應用於P型氧化鋅/N型氮化鎵異質接面二極體之研究

Investigations on the Cosputtered Transparent Electrode Ohmic Contacts to N-GaN and Its Applications to P-ZnO/N-GaN Heterojunction Diode

吳南傑(Nan-Jay Wu)

指導教授 ： 劉代山

國立虎尾科技大學/電機資訊學院/光電與材料科技研究所/碩士(2012年)

摘要

本研究在氮化鎵磊晶層上製作傳輸線模型，於室溫下利用射頻磁控式共濺鍍系統，選擇氧化鋅以及氧化銦錫為共濺鍍靶材，沉積鋅原子摻雜濃度之理論值為33%的氧化銦錫-氧化鋅共濺鍍導電薄膜作為歐姆接觸電極，藉由半導體參數分析儀、歐傑電子能譜儀之縱深分佈、可見光-紫外光光譜儀量測歐姆接觸特性變化及機制。研究結果顯示，氧化銦錫-氧化鋅與n型氮化鎵無法得到歐姆接觸特性，而鈦/鋁、鈦/氧化銦錫-氧化鋅金屬與n型氮化鎵在在快速熱退火處理前具有優異歐姆接觸特性，其特徵電阻值分別為5.09×10−4 Ωcm2與4.82×10−5 Ωcm2；穿透率方面在氧化銦錫-氧化鋅與n型氮化鎵間加入薄鈦金屬，雖然平均可見光穿透率有下降趨勢，但材料參數φ則明顯的提升。最後，製作p-ZnO/n-GaN與p-ZnO/i-ZnO/n-GaN之異質接面結構二極體，分別以鈦/鋁以及鈦/氧化銦錫-氧化鋅透明電極作為與n型氮化鎵歐姆接觸電極，以鎳/氧化銦錫透明電極作為與p型氧化鋅歐姆接觸電極，以半導體參數分析儀及螢光光譜儀量測發光二極體之電流-電壓特性與電激發放射光譜，結果顯示，異質接面二極體（p-ZnO/ n-GaN、p-ZnO/i-ZnO/n-GaN）結構均有p-n接觸之整流二極體特性，但由電激發放射光譜可得知，並無顯著的電激發光發射峰值，推論可能的原因是p-ZnO/ n-GaN以及p-ZnO/i-ZnO/n-GaN異質接面二極體經過熱退火製程後，由於介面擴散的機制，進而劣化氮化鋁-氧化鋅共濺鍍薄膜導電型態影響介面接觸與特性，因而沒有明顯的電激發發光放射。

關鍵字

射頻磁控濺鍍法 ； 氧化鋅薄膜 ； 氮化鋁-氧化鋅共濺鍍薄膜 ； 氧化銦錫-氧化鋅共濺度薄膜 ； 異質接面發光二極體

並列摘要

In this study, the transmission line model produced in the GaN epitaxial layer at room temperature was usingt the RF magnetron sputtering system, the zinc oxide and the indium tin oxide were slected for the sputtering targets to deposite the indium tin oxide-zinc oxide conductive film a theoretical value of the zinc atoms doping concentration for 33% as the ohmic contact electrodes., Auger electron spectroscopy of the depth distribution of visible light - ultraviolet spectrometer measured ohmic contact characteristics change mechanism. The results show that indium tin oxide - zinc oxide and n-type GaN can not be the ohmic contact, while the titanium / aluminum titanium / indium-tin oxide - zinc oxide and n-type GaN before the rapid thermal annealing excellent ohmic contact, characterized by resistance values were 5.09 × 10-4 Ωcm2 4.82 × 10-5 Ωcm2; penetration aspects of the indium tin oxide - zinc oxide between the n-type GaN thin titanium metal, although the average the transmittance of visible light on a downward trend, but the material parameter φ is significantly improved. Finally, the production p-ZnO/n-GaN with the heterostructures p-ZnO/i-ZnO/n-GaN the diode, Ti / Al and Ti / indium-tin oxide - zinc oxide transparent electrode as n type GaN ohmic contact electrode, a nickel / indium-tin oxide transparent electrode as the electrode contact with the p-type ZnO ohm, the measured light-emitting diode semiconductor parameter analyzer and fluorescence, the amount of current - voltage characteristics and electrical excitation radiation spectrum, the results show that the heterojunction diode (p-ZnO / n-of GaN p-ZnO/i-ZnO/n-GaN) structure has a pn-contact rectifier diode characteristics, but from electrical excitation emission spectrum informed that no significant electrical excitation light emission peak infer possible causes of the p-ZnO / n-GaN and p-ZnO/i-ZnO/n-GaN heterojunction diodes after thermal annealing process, due to interface diffusion mechanism, and thus deterioration of the aluminum nitride - zinc oxide sputtered thin films of conductive patterns affect the interface contacts and features, and thus there is no obvious electrical excitation light-emitting radiation.

並列關鍵字

F magnetron cosputtering system ； ZnO films ； AlN codoped zinc oxide thin films ； ZnO codoped indum tin oxide thin films ； heterojunction diode

參考文獻

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