本論文利用以磁控濺鍍沉積之氧化銦鉿鎵薄膜，討論在不同製程參數下，對薄膜特性的影響以及其紫外光電元件的應用，包括了紫外光感測器與薄膜電晶體。
第一部分，我們使用磁控共濺鍍技術沉積氧化銦鉿鎵薄膜，共濺鍍的靶材分別使用氧化銦鎵以及氧化鉿。在沉積過程中，調整共濺鍍的功率比例以及氧氣和氬氣的通入比例，獲得不同特性的薄膜。然後對這些薄膜進行光學、結構和材料分析。在光學方面，發現氧化銦鉿鎵薄膜在可見光下具有近90%的高透過率，並計算出不同樣品的能帶。在結構分析方面，不同氧氣含量的薄膜表面均勻且呈非晶態。在材料分析方面，X射線光電子能譜顯示，隨著氧化鉿濺鍍功率的增加，薄膜中的氧空缺逐漸減少。
第二部分，利用磁控共濺鍍的方式來製作氧化銦鉿鎵的光感測器。首先探討不同電極對於光感測器的影響，製作了鋁電極以及鎳金電極光感測器，觀察到鋁電極和氧化銦鉿鎵呈現歐姆接觸，因此無法抑制暗電流，而鎳金電極和氧化銦鉿鎵呈現蕭基接觸，因此有更高的光暗電流比和響應拒斥比。接著我們探討不同濺鍍功率比對於氧化銦鉿鎵光感測器的影響。在共濺鍍功率比80/60 W光感測器有較高的響應度2.88×10-3以及拒斥比712.91；而在共濺鍍功率比80/80 W光感測器有較好的時間響應，其開關時間分別為2.33 (sec) 和6.18 (sec)。
第三部分，利用磁控共濺鍍的方式來製作氧化銦鉿鎵的薄膜電晶體。透過改變共濺鍍的功率比，調整鉿在薄膜中的比例，以提高薄膜電晶體特性。接著在共濺鍍時調整氧氣和氬氣的通入比例，以減少氧空缺造成的影響，薄膜電晶體的特性亦獲得了改善，並且得到了氧化銦鉿鎵薄膜電晶體在共濺鍍功率80/60 W通氧量4% 的條件下的最佳參數，其開關電流比為108，場效電子遷移率為3.05 (cm2/Vs)，次臨界擺幅為88.85 (mV/decade)。接著，我們把氧化銦鉿鎵薄膜電晶體作為光電晶體進行照光量測，得到7.72×103的拒斥比，證實氧化銦鉿鎵也可以應用在光電晶體上。最後，為了近一步改善電晶體特性，我們以原子層沉積的方式沉積氧化鋁作為高介電係數氧化層，並且得到電晶體特性的小幅改善。

In this thesis, we investigate the properties of indium-hafnium-gallium oxide (IHGO) thin films deposited by RF magnetron sputtering and explore their applications in ultraviolet (UV) optoelectronic devices, including UV photodetectors and thin-film transistors (TFTs).
In the first part, IHGO thin films were deposited using co-sputtering with indium-gallium oxide (IGO) and HfO2 targets. We adjusted the co-sputtering power ratios and oxygen flow ratios during the deposition process to obtain films with varying properties. Optical, structural, and material analyses were performed on these films. Optically, IHGO thin films exhibited high transparency, with over 90% transmittance in the visible range, and the bandgap of the samples was calculated. Structurally, films with different oxygen contents were uniform and amorphous. Material analysis via X-ray photoelectron spectroscopy (XPS) revealed that oxygen vacancies in the films decreased with increasing hafnium sputtering power due to the strong Hf-O bonds.
In the second part, IHGO photodetectors were fabricated using the co-sputtering method. We first investigated the effects of different electrodes on the photodetectors by fabricating devices with aluminum (Al) and nickel/gold (Ni/Au) electrodes. It was observed that Al electrodes formed ohmic contacts with IHGO, resulting in high dark current, whereas Ni/Au electrodes formed Schottky contacts, leading to higher photo-to-dark current ratios and rejection ratios. We then explored the impact of different co-sputtering power ratios on IHGO photodetectors. The photodetector with an 80/60 W co-sputtering power ratio exhibited a higher responsivity of 2.88×10-3 (A/W) and a rejection ratio of 712.91, while the 80/80 W device showed better time response with switching times of 2.33 (s) and 6.18 (s) for rising time and falling time, respectively.
In the third part, IHGO TFTs were fabricated using the co-sputtering method. By varying the co-sputtering power ratios, we adjusted the hafnium content in the films to enhance the TFT characteristics. Additionally, the oxygen flow ratios were modified during co-sputtering to reduce the impact of oxygen vacancies, leading to improved TFT performance. The optimal parameters were obtained for IHGO TFTs co-sputtered at 80/60 W with 4% oxygen flow, yielding an on/off current ratio of 108, field-effect electron mobility of 3.05 (cm2/Vs), and a subthreshold swing of 88.85 (mV/decade). Subsequently, we measured the phototransistor characteristics of IHGO TFTs under illumination, achieving a rejection ratio of 7.72×103, confirming the potential of IHGO for phototransistor applications. Finally, to further improve the transistor characteristics, we deposited an aluminum oxide (Al2O3) high-k dielectric layer using atomic layer deposition (ALD), which resulted in slight improvements in the TFT performance.
In conclusion, this thesis demonstrates the fabrication and optimization of IHGO thin films and their application in UV photodetectors and TFTs. By adjusting deposition parameters, we achieved significant improvements in device performance, highlighting the potential of IHGO for advanced optoelectronic applications.

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