這項研究的目的是研究一種低成本的液相沉積(LPD)方法來製備氧化鎵(β-Ga2O3)薄膜，該方法具有無真空且易於製造的優點，使得該方法適用於大面積製造。首先，採用 LPD 方法在 pH 值為 8 且溫度為 80°C的條件下沉澱 GaOOH 顆粒，從而成為氧化鎵(β-Ga2O3)薄膜的前驅體。同時，將濃度分別為 0.1 M，0.3 M 和 0.5 M 的氟化銨(NH4F)添加到溶液中，以形成氟摻雜(F-doped)的 GaOOH。然後，透過配備在場發射掃描式電子顯微鏡(FESEM)上的能量分散X射線光譜儀(EDS)分析了元素F，Ga 和 O 的沉澱 F 摻雜GaOOH 粉末，我們發現 F 元素比例隨著 NH4F濃度的增加而增加。接下來，將沉積的薄膜在 900℃下退火 4 小時以將F 摻雜的 GaOOH 轉變成 F 摻雜的 β-Ga2O3。再次使用 EDS 分析 F 摻雜的 β-Ga2O3薄膜，我們發現 F 元素比例也隨著 NH4F 濃度的增加而增加。此外，我們進行 XPS 分析以間接證明 F 摻雜的 β-Ga2O3 薄膜中觀察到F-離子的存在。最後，用不同濃度的 F 摻雜 β-Ga2O3 薄膜製作 F 摻雜β-Ga2O3/p+-Si 接面二極體。其 J-V(電流密度-電壓)特性得到了很好的研究。研究證明，該方法藉由提高 NH4F 的濃度來改善氧化鎵薄膜的電性能。同時，該方法還顯著改善了 F 摻雜 β-Ga2O3/p+-Si接面的整流特性。第二部分是利用射頻磁控濺鍍(RF magnetron Sputter)製備了氧化銦
鎵薄膜應用於薄膜電晶體。氧化銦鎵薄膜的透射率在可見光區域內是大於 70％。經由霍爾效應(Hall effect)量測，In0.8Ga1.2O3(In2O3:Ga2O3=40:60)薄膜的載子濃度為2.31×1018cm-3，電阻率為 0.982Ω.cm，載子遷移率為2.76cm2V-1S-1。在暗室中測量氧化銦鎵薄膜電晶體(閘極長度為 100μm，閘極寬度為 1000μm)的轉移特性曲線，其開關比為 2.44×102，次臨界擺幅(SS)為 1.786V/decade，介面缺陷密度(Dit)為2.082×1012cm-2。

The purpose of this research is to investigate a low-cost Liquid Phase Deposition (LPD) method for preparing gallium oxide (β-Ga2O3) films, which possesses an advantage of the non-vacuum and easy-fabrication process, making the approach suitable for large-area manufacture. Firstly, implemented the LPD method to precipitate the GaOOH particles under the pH value of 8 and at 80°C, which became the precursor of gallium oxide (β-Ga2O3) films. Ammonium fluoride (NH4F) with concentrations of 0, 0.1 M, 0.3 M, and 0.5 M were then added into the solution to form fluorine-doped (F-doped) GaOOH. Afterward, analyzed the precipitation F-doped GaOOH powders by the Energy-dispersive X-ray Spectroscopy (EDS) equipped on a Field-Emission Scanning Electron Microscopy
(FESEM) for elemental F, Ga, and O, and we found that the F ions’ concentration
increased with the NH4F concentration. Next, annealed the deposited films at 900°C for four hours to transform the F-doped GaOOH composition into F-doped β-Ga2O3composition. Used EDS again to analyze the F-doped β-Ga2O3 films, and we discovered that their F ions’ concentration also increased with the NH4F concentration. Further, we conduct XPS analysis to prove the existence of Fions in the F-doped β-Ga2O3 films. Finally, the F-doped β-Ga2O3 films of different concentrations were used to fabricate the F-doped β-Ga2O3/p+-Si junction diodes; their J-V (current-voltage) properties were well investigated. The research has proven that the approach can increase NH4F concentration and the electrical performance of F-doped gallium oxide. Meanwhile, the method has also improved the rectification characteristics of the F-doped β-Ga2O3/p+-Si junction significantly. The second part utilizes an RF magnetron sputter to prepare indium-gallium oxide films for the use of thin-film transistor. The transmittance of the indium-gallium oxide in the visible spectrum is larger than 70%. With the measurement of Hall Effect, the carrier concentration of In0.8Ga1.2O3(In2O3:Ga2O3 = 40:60) is 2.31×1018 cm-3, the resistivity is 0.982Ω.cm, and the mobility is 2.76cm2V-1S-1. After measuring the transfer curve of IGO-TFT in a darkroom (with 100 μm gate length and 1,000 μm gate width), the On/Off ratio is 2.44×102, the Subthreshold Swing (SS) is 1.786V/decade, and the Interface Trap Density (Dit) is 2.082×1012cm-2.

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