本論文是由兩部分組成。第一部分探討3D結構TiO2 MSM紫外光線感測器的研製。吾人先利用硝酸銀及氫氟酸之蝕刻溶液於P型(100)矽基板形成奈米柱狀結構，再利用射頻濺鍍系統(Sputtering system)成長二氧化鈦（TiO2）薄膜，然後蒸鍍指叉金（Au）電極形成TiO2/Au/TiO2(Metal-Semiconductor -Metal)紫外光感測器 。之後再將其以不同的氣體( O2,N2) 進行退火來進一步比較各種參數之元件特性差異。此 外，吾 人 也 先 在矽基板上鍍上三氧化二鋁(Al2O3)薄膜，進而再於 其 上完成MSM紫外光感測器來做比較。
最後分別照射了長波紫外光線 (波長：366 nm)及短波紫外光線(波長：256 nm)以測量其光電流及暗電流增益。實驗顯示， 3D結 構因 能 同 時 增 加 運作表 面/ 體 積 比 (S/V) 及 光 吸 收效 率， 故 能大 大 的 提 升 光 增 益。 又 不 論 是 2D 或 3D 結 構 的 MSM紫外光線感測器，在長波紫外光線照射下 的 光 增 益皆大 於 短波紫外光線照射下者， 顯示 本 元 件 對 長波紫外光線 感 測 較 敏 感。此 外，經由吸收光譜及 XRD 分析 ，發現O2退火後 的TiO2薄膜比沒退火者有較佳薄膜品質及較高UV光吸收率，故導至 以O2退火的元件又優於以N2者。另外，比較使用玻璃 與矽晶為基板 的樣品有類似的漏電流可判定添 加 Al2O3 於矽晶基板的做用是 在 於其可減少經由矽基的漏電流。
本論文的第二部分為四元奈米結晶Cu2CoSnS4(CCTS)材料光電特性的研究。首先利用濕式化學法中在氮氣中合成Cu2(Co1-xZnx)SnS4奈米晶粉末，並以XRD、SEM、Raman等分析材料性質。再 利 用 旋 轉 塗抹(spin coating) 法於矽晶及玻璃基板製作MSM 元 件 來研究該材料 的光電特性。由Hall measurement 知 濕式化學法合 成的CCTS 為一負型半導體。移動率約為210cm2/v-s。由XRD及 SEM 看出該材料 是多晶的奈米結晶,晶粒的大小分布約幾個nm到100nm左右。
另由元件的光電特性量測發現CCTS對於可見光的感測約2倍大於UV光及IR光。如同第一部分的TiO2 MSM感測器,在矽基板上的元件由於漏電流的產生導致其光增益遠小於在玻璃基板上的元件。
由本研究可知CCTS四元材料對於可見光頻譜有明顯的吸收效果,加上其能隙的可調性,可預知CCTS將會是一個發展低成本高效率多接面疊合式的太陽能電池的好材料。

Summary：
In this thesis, firstly, we developed the TiO2 thin film with 3D nano rods metal-semiconductor-metal (MSM) structure for high performance UV light detecting applications. To prepare the UV detector, the p(100) Si substrates were etched by AgNO3 mixed HF solution to form nano rods structure firstly. Then the intrinsic layer Al2O3 film was deposited on the Si nano rods with radio frequency sputtering system, and followed by deposition of TiO2 film as light sensing element with the same system. In final, Au metal was deposited thermally on the top through a finger type metal mask as the electrode contact to complete the device.
Next, the sensors were annealed under oxygen and nitrogen gas ambient conditions, and then measured their optical-electrical characteristics with HP-4140 with long (366nm) and short (256nm) length UV light sources. Experiment results show the sensor has a higher sensitivity to a long UV light, especially for the sample with the Al2O3 i layer. We attribute this to the leakage current resistance ability of the Al2O3 layer. Besides, the sample under oxygen gas ambient annealing can have a higher optical current than that under nitrogen gas annealing or without annealing. After having examined the TiO2 film absorption and XRD spectrum, the TiO2 film with oxygen anneal has gained both higher absorption in UV range and film crystalline.
In the second part, we studied the electron optic properties of the compound material Cu2CoSnS4 (CCTS). The CCTS has been developed for low cost high efficiency solar cell. In the past, researches were concentrated on the band gap tuning; only very few electron optic properties have been discussed. In this thesis, we measured these properties through the MSM structure.
Initially, the CCTS nano powder was formed by solvothermal method and used XRD, SEM and Raman to examine the film basic properties. Then spin coated the powder on both Si and glass substrates to prepare MSM devices. Based on SEM photos, one can find the film contains quaternary semiconducting nanoparticles with size distribution from 20 nm to 60 nm. In addition, it is a negative type semiconductor and has a nano poly crystal structure with mobility at 210cm2/v-s as found from both XRD analysis and Hall measurement. Besides, band gap of CCTS film was estimated to be 1.3-1.5 eV dependent on Zn content from the UV-Visible spectrum measurement.
The measured MSM structure optical currents indicate the CCTS compound has a higher sensitivity to a visible light than that of UV and IR lights. Therefore, the solvothermal method prepared CCTS will be a potential candidate material for low cost and high performance solar cell applications.

＊Author
＊＊Advisor
Keywords： TiO2 、MSM UV Detector、 3D nano structures、 Al2O3

In this thesis, we developed the TiO2 Thin Film with 3D nano structures for high performance metal-semiconductor-metal (MSM) UV light detecting applications. Firstly, the p(100) Si substrates were etched by AgNO3 mixed HF solution to form nano rods structure. Then the intrinsic layer Al2O3 film was deposited on the Si nano rods with radio frequency sputtering system, and followed by deposition of TiO2 as light sensing element. In final, Au metal was deposited thermally on the top through a finger type metal mask as the electrode contact to complete the device.On solvothermal synthesis of Cu2CoSnS4 alloys at 270˚C for 24 h in OLA, the Co(CH3COO)2 precursor was superior to CoCl2 and Co(NO3)2 precursors in enhancing the growth of pure and stoichiometric Cu2CoSnS4 nanocrystals. This result may be explained in terms of the hybridization of valence and conduction bands of Cu2CoSnS4 and Cu2ZnSnS4. The Cu2(Co1-xZnx)SnS4 nanocrystals with tunable bandgap may be promising candidates for photovoltaic applications. We also developed the Cu2CoSnS4 Thin Film with 2D structures for metal-semiconductor-metal (MSM) structure devices and find it sensitive for the visible light.

[1] E. Monroy, F. Calle, C. Angulo, P. Vila, A. Sanz, J. A. Garrido, E.
Calleja, E. Mũoz, S. Haffouz, B. Beaumont, F. Omnes, and P.
Gibart, "GaN-Based Solar-Ultraviolet Detection Instrument,"
Applied Optics, vol. 37, no. 22, pp. 5058-5062, Aug. 1998
[2] Hadis Morkoc, Aldo Di Carlo, and Roberto Cingolani,
“GaN-based modulation doped FETs and UV detectors,”
Solid-State Electronics, vol. 46, pp.157–202, Feb. 2002
[3] 莊嘉琛, 太陽能工程--太陽能電池篇 台北：全華圖書股份有限公司, 2008.
[4] S. E. Shaheen, D. S. Ginley, and G. E. Jabbour, "Organic-based photovoltaics. toward low-cost power generation," MRS Bul., vol. 30, pp. 10-19, 2005.
[5] F.Shinoki and A. Itoh, “Mechanism of rf reactive sputtering,”Journal of Applied Physical., vol. 46, p. 3381, 1975.
[6] 賴耿陽，“IC 製程之濺射技術”，復漢出版社 1997年。
[7] 王福貞，聞立時，“表面沉積技術”，機械工業出版社，pp.114-204。
[8] 莊達人，”VLSI製造技術”，高立圖書股份有限公司，1995年。
[9] Wen-I Hsu , Shui-Jinn Wang “Fabrication and Characterization of Single-Crystalline Silicon Nanowires Prepared by Metal-Induced Etching ” , National Cheng Kung University , 2008
[10] A. Uhlir, Jr., “Electrolytic Shaping of Germanium and Silicon,”
Bell System Tech. J., vol. 35, pp. 333-347, 1956.
[11] G. C. John, and V. A. Singh, “Diffusion-induced nucleation model
or the formation of porous silicon,” Physical Review B, vol. 52,
no. 15, pp. 125-131, 1995.
[12] K. Imai, and S. Nakajima, “Full isolation technology by porousoxidized silicon and its application to LSIs,” International ElectronDevices Meeting, vol. 27, pp. 376-379, 1981.
[13] L. T. Canham, “Silicon quantum wire array fabrication by
electrochemical and chemical dissolution of wafers,” Appl. Phys.
Lett., vol. 57, no. 10, pp. 1046-1048, 1990.
[14] V. Lehmann, and U. Gosele, “Porous silicon formation: A quantumwire effect,” Appl. Phys. Lett., vol. 58, no. 8, pp. 856-858, 1991.
[15] D. R. E. Adams. W. G, "The Action of Light on Selenium," The Journal of the Society of Telegraph Engineers, vol. 167,pp. 313-349, 1877.