低壓氫退火改善直線式連續濺鍍氧化鋅共摻雜鎵鋁薄膜特性

Low Pressure Hydrogen Annealing in Improving Electrical and Optical Properties of In-line Sputtered Gallium and Aluminum Co-doped Zinc Oxide Films

傅守璽(Shou-shi Fu)

指導教授 ： 張慎周

共同指導教授 ： 林天財(Tien-Chai Lin)

崑山科技大學/工程學院/電機工程研究所/碩士(2010年)

摘要

經過氫氣退火後處理氧化鋅共摻雜鎵鋁薄膜之電性與光學性質是否有所提升，本研究中是使用直線式連續濺鍍實機台來濺鍍沉積氧化鋅共摻雜鎵鋁薄膜，製程中利用不同基板溫度製作薄膜，之後使用氫退火爐在低壓環境下通入氫流量100 sccm分別進行200℃、300℃退火與微波氫電漿，而工作壓力設為25 Torr。進行氫氣退火後之薄膜的不同物理特性分析，經由X-ray繞射觀察薄膜晶格結構，場發射顯微鏡(SEM)觀察其表面微結構，霍爾來量測電性，光譜儀量測光穿透率。
經實驗後結果發現直線式連續濺鍍的薄膜，經氫退火後的電阻率都是以退火溫度在300℃時阻率都是最低的，阻值率最低的是基板沉積溫度在200℃的薄膜是阻值最好的，阻值是6.6×10-4 Ω-cm。氫退火的薄膜在可見光範圍的光波長400 nm至800 nm可達到80％以上的平均光穿透率；氫電漿處理後得到90%以上，並在製程靜態式基板200℃可達96%，利用SEM來觀察薄膜之表面形貌，發現薄膜晶粒有變大且緻密的現象。連續式製程在XRD繞射結構圖發現，製程基板溫度未加熱著薄膜經過氫退火後，都發生氧化鋅優選取向(002)面強度降低，推測是經過氫退火後薄膜應力由介面處開始釋放所導致的現象；氫電漿處理後，繞射峰強度均為最低，推測是薄膜表面形貌粗造化所導致的現象。
本研究結果可以作為太陽能電池或是平面顯示器工業所使用連續式濺鍍機台製作氧化鋅共摻雜鎵鋁薄膜經氫處理改善光電性質的依據。

關鍵字

連續式濺鍍 ； 氫退火 ； 氫電漿退火

並列摘要

To evaluate the possibility in improving electrical and optical properties of gallium and aluminum co-doped zinc oxide （GAZO）films by hydrogen treatment, in-line sputtered GAZO films with a series of hydrogen treatment were performed. Hydrogen treatment was set with constant 100 sccm gas flow, 25 torr, and varied 200oC, 300oC or plasma annealing. Electrical, optical and microstructure properties of GAZO films before and after hydrogen treatment were measured by hall measurement, spectrometer, scanning electron microscope and X-ray diffraction meter.
Experimental results indicate GAZO films after 300oC hydrogen annealing show lower electrical resistivity than those after other hydrogen treatment. The lowest electrical resisitivity among all GAZO films after 300oC annealing corresponds to 200oC substrate temperature during films sputtering process, and is 6.6X10-4 ohm-cm. The average optical transmittance in visible wavelength region for GAZO films after hydrogen thermal annealing is above 80%; for those after hydrogen plasma annealing is above 90%. The grain size grows for GAZO films after hydrogen treatment observed from scanning electron microscope. The X-ray diffraction intensity corresponding to preferential （002）crystal plane of zinc oxide decreases for GAZO films with unheated substrate temperature during sputtering and after hydrogen treatment compared with those before treatment. This may be caused by anisotropic stress of GAZO films release triggered by hydrogen treatment. The anisotropic stress to GAZO films could be produced during in-line sputtering.
This work can contribute to flat panel display, thin films solar cells, touch panel industries if GAZO films were considered as transparent electrode candidates.

並列關鍵字

in-line sputtering ； hydrogen annealing ； hydrogen plasma annealing

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