本論文針對釓摻雜氧化鋅鋁(Gd-doped Aluminum Zinc Oxide, Gd:AZO)透明導電薄膜(transparent conductive thin film)進行材料特性量測分析，並且探討其與未摻雜之氧化鋅鋁(ZnO:Al2O3=98 wt.%:2 wt.%)薄膜光電特性差異。 本實驗利用共濺鍍系統(co-sputter)成長薄膜，以多層膜的方式將釓摻雜氧化鋅鋁薄膜濺鍍在石英玻璃(quartz)基板上，多層膜結構一共分成五層AZO/Gd/AZO/Gd/AZO，改變Gd與AZO在多層膜結構中厚度比例，得到不同濃度釓摻雜氧化鋅鋁導電薄膜。沉積以後經由適當的熱處理，利用霍爾量測 (Hall Measurement)量測電性，以紫外光/可見光分光光譜儀 (UV/VIS Spectrophotometer)系統量測其穿透率光譜、橢圓儀 (Ellipsometer)系統量測其折射率和X-ray繞射儀(X-ray diffraction，XRD)觀察薄膜結晶特性分析其結構，且利用氧化鋅鋁導電機制合理探討各種量測結果，針對氧化鋅鋁薄膜的摻雜效應深入探討。 氧化鋅鋁(AZO)薄膜的穿透率在近紫外光穿透率可達85%以上且在400 ℃真空下熱處理後電阻率可達1.3×10-2 Ω-cm，在摻雜釓(Gd)之後吸收波長邊界有藍位移(blue-shift)的現象，並且在200 ℃真空下熱處理電阻率即可達4.4×10-3 Ω-cm。計算透明導電薄膜FOM(figure of merit)值，摻雜10 wt.% 釓的氧化鋅鋁薄膜相對於未經過摻雜之氧化鋅鋁薄膜可獲得較好的FOM值。 經由本研究可知，Gd:AZO薄膜因具有高光穿透率與良好之電性，因此為替代氧化銦錫(ITO)來當成透明導電層應用在氮化鎵發光二極體(GaN-based LED)上的潛力。 This study focuses on the electrical and optical properties of Gd-doped AZO transparent conductive thin film, and discuss the difference in doping effect on AZO (ZnO:Al2O3=98 wt.% : 2 wt.%). In this experiment, we use the co-sputter system to deposit the thin film, and using the multilayer structure (AZO/Gd/AZO/Gd/AZO) to achieve the Gd-doped AZO process. A multilayer of five layers was deposited on the quartz substrate, by altering the Gd layer thickness we could get different doping contents on AZO. After deposition, the proper annealing process is needed. Using the Hall Measurement to measure the electrical property, the UV/VIS Spectrophotometer to measure the transmittance, the refractive index by Ellipsometer and the X-ray to analyze the structure, then we could know whether Gd-doped AZO performs better than un-doped AZO. The Figure of Merit helps us to evaluate the application of the films. AZO thin films could get over than 85% transmittance in near UV region, and after doing 400 ℃ heat treatment in vacuum ambient, the resistivity can be obtained to 1.3×10-2 Ω-cm. After Gd dope into AZO, the absorption edge shift results from the Burstein-Moss effect, and we could get the relative low resistivity by 10 wt. % Gd-doped AZO after 200 ℃ heat treatment in vacuum ambient. We could get the best FOM by 10 wt. % Gd-depod AZO. From this research, Gd-doped AZO thin film has high transmittance and better conductivity, so it might be a suitable candidate to replace ITO in the application of transparent conductive layer (TCL) in GaN-base LED.
