本論文在於探討利用超音波噴塗熱裂解沉積法製備非晶氧化銦鎵鋅透明薄膜電晶體。超音波噴塗熱裂解沉積法是一種高品質、低成本、非真空製程和利於調整摻雜濃度的沉積技術。我們利用此方法製備介電層與主動層。在電極材料上，我們選擇使用透明氧化物-氧化鋁鋅。氧化鋁鋅擁有高透光度、高導電率和成本較低等優點，且較氧化銦錫穩定。本研究利用此沉積法成功製作底閘極結構之透明薄膜電晶體。
為了瞭解氧化銦鎵鋅的結構、化學組成、粗糙度、結晶性和透光度，本研究利用了（一）掃描式電子顯微鏡、（二）X射線繞射分析、（三）原子力顯微鏡、（四）X射線光電子能譜、（五）光致發光、（六）紫外光-可見光-近紅外光分光光譜儀。首先利用掃描式電子顯微鏡、X射線繞射分析和原子力顯微鏡確認氧化銦鎵鋅表面狀況及結晶性，再透過X射線光電子能譜確認化學組成及氧空缺的比例，接著與光致發光量測結果做比較。最後利用紫外光-可見光-近紅外光分光光譜儀量測製作完的透明薄膜電晶體之透光度。
運用超音波噴塗熱裂解沉積法製作完成非晶氧化銦鎵鋅透明薄膜電晶體後的電性表現上，電流開關比達108以上，次臨界擺幅為0.174 V/dec，電子移動率為7.64 cm2/V-s。而在穩定度的量測上，我們利用閘極加偏壓5伏特和 − 5伏特持續3000秒觀察此電晶體之穩定度。另外我們比較氧化銦鎵鋅薄膜中氧空缺含量對電性和穩定性的影響。為了瞭解非晶氧化銦鎵鋅透明薄膜電晶體之光響應，我們測量其在光波長250 nm至450 nm下之光響應程度，分析此薄膜之截止波段並推算出薄膜的能隙，最後比較透明氧化物電極和金屬電極對光響應之影響以及氧空缺含量對光響應之影響。
在本論文中，利用超音波霧化熱裂解沉積法製備非晶氧化銦鎵鋅透明薄膜電晶體，相對於其他真空或非真空製程方式在製程時間、花費成本上均有極大的優勢。電性表現、穩定性和光響應亦有良好的表現。而在氧空缺研究上，我們證明氧空缺對電晶體特性之影響。綜合電性表現和成本考量等因素，此沉積法在未來商業運用上擁有極大的優勢和發展。

This thesis mainly investigates the amorphous IGZO transparent thin film transistor (a-IGZO TTFT) deposited by ultrasonic spray pyrolysis method. Ultrasonic spray pyrolysis deposition (USPD) is a high quality, low cost, non-vacuum process and favorable to adjust the doping concentration of the deposition technology. We use this method to fabricate the dielectric layer and the active layer of TFT. On the electrodes material, we choose to use the transparent conduct oxide-alumina zinc (AZO). AZO has the advantages of high transparency, high conductivity and low cost, and is more stable than indium tin oxide (ITO). We successfully fabricated the bottom gate a-IGZO transparent thin film transistor by using USPD.
In order to understand the structure, chemical composition, roughness, crystallinity and transmittance of IGZO thin films. The (1) Scanning Electron Microscopy, (2) X-ray Diffraction analysis, (3) Atomic Force Microscopy, (4) X-ray Photoelectron Spectroscopy, (5) Photoluminescence, and (6) UV/VIS/NIR Spectrometers are adopted in this work. First, scanning electron microscopy, X-ray diffraction and atomic force microscopy were made use of confirming the surface, roughness and crystallinity of the IGZO thin films. Next, X-ray photoelectron spectroscopy was used to make sure the chemical composition and the ratio of oxygen vacancy content, and then compared with the results of photoluminescence measurements. Finally, UV/VIS/NIR spectrometers were utilized to measure the transmittance of the transparent thin film transistors.
On the electrical characteristics of a-IGZO TTFTs deposited by USPD, the on/off ratio is 108, the subthreshold swing is 0.174 V/dec, and mobility is 7.64 cm2/V-s. To measure the stability of the TTFTs, the gate bias voltage of 5 V and − 5 V was stressed during 3000 sec. In addition, we compare the influence of oxygen vacancy content in IGZO thin films on electrical characteristics and stability.
In order to understand the spectra response of a-IGZO TTFTs, we measured the responsivity with the range of wavelength from visible region (450 nm) to UV region (250 nm) and then we analyzed the cutoff wavelength to calculate the energy bandgap of the thin films in advance. At last, the influence of transparent oxide electrode and metal electrode on light responsivity and the influence of oxygen vacancy content on light responsivity are compared.
In this thesis, the fabrication of a-IGZO TTFTs by USPD has great advantages in process time and cost in comparison with other vacuum or non-vacuum process methods. The electrical characteristics, stability and light responsivity also have good performance. In the study of oxygen vacancy, we proved the influence of oxygen vacancy on transistor characteristics. Comprehensive electrical performance and cost considerations, this deposition in the future commercial use has a great advantage and development.

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