藉由大氣電漿在不同狀態下沉積氧化鋅摻雜鎵薄膜其光電特性與材料分析之研究

Abstract

本研究利用常壓電漿化學氣相沉積系統在加熱機板上來沉積摻雜鎵的氧化鋅薄膜(GZO)，藉由改變鎵摻雜濃度、基板溫度、基板到噴嘴出口距離、掃描次數、載入氣體流量和硝酸鋅濃度等參數，探討製程參數對於其物理特性的影響，利用X光繞射分析儀、X光電子能譜、光激光譜儀、掃描式電子顯微鏡、原子力顯微鏡、分光光譜儀、霍爾量測和四點探針等儀器來觀察GZO薄膜的結構、表面形貌和光電特性，並藉由其分析結果定義出最佳製程條件之GZO透明導電膜。 由XRD中可知薄膜為多晶型態且為六方最密堆積的柱狀結構，主要的晶向為(002)，最佳的試片電阻率為8x10-4 cm，且在可見光區段透光率能超過80%以上，這樣的結果代表利用常壓電漿化學氣相沉積系統來沉積摻雜鎵的氧化鋅薄膜可以被應用來當作光電元件的透明電極。

Ga doped Zinc oxide (GZO) films have been deposition by the atmospheric pressure plasma chemical vapor deposition (APPCVD) onto preheated glass substrates using Zn(NO3)2 and Ga(NO3)2 as precursors for Zn and Ga ions, respectively. The effect of the Ga dopant concentration , substrate temperature, gap distance, scan times, carrier gas flow rate, and Zn(NO3)2 concentration on the physical properties of the ZnO and GZO thin films was analyzed. The effect on the structural, morphological, optical, optical and electrical properties of APPCVD ZnO thin films were investigated using x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), photoluminescence (PL), scanning electron microscopy (SEM), atomic force microscopy (AFM), spectrophotometer, Hall measurement and four point probe. According to the above analysis the best deposition parameters of GZO thin film can be determined. XRD studies reveal that films are polycrystalline with hexagonal (wurtzite) crystal structure. The thin films were mainly oriented along the (002) plane. The best sample with a resistivity of 8x10-4 cm and a transmittance of over 80% in visible region was achieved. This result makes APPCVD GZO thin film potentially applicable as transparent electrode in opto-electrical devices.