含銦鋅氧化物之薄膜電晶體之濕式製程研究

本研究以多醇法（Polyol Process）製備銦鋅氧化物薄膜（Indium-doped Zinc Oxide，IZO）並應用於薄膜電晶體（Thin-film Transistor，TFT）之製作。實驗以乙二醇（Diethylene Glycol，DEG）為溶劑/螯合劑，醋酸鋅（Zinc Acetate）和醋酸銦（Indium Acetate）為鋅與銦之來源，聚乙烯基吡咯烷酮（Polyvinylpyrrolidone，PVP）為保護劑，在180C持溫2小時合成出IZO前驅物溶液，再經由離心作用將所得到之前驅物均勻分散在正戊醇（Pentanol）中，以旋轉塗佈法（Spin-coating）在玻璃基板上形成薄膜，並在大氣下進行退火形成IZO薄膜。研究過程中嘗試改變之製程參數包括反應溫度、反應時間、水添加量、退火溫度以及退火時間以探討薄膜結構與性質之變化；此外，更以IZO為元件通道層（Active Channel Layer），鍍上電極製成TFT元件，進行電性質之量測分析。本研究亦添加不同比例之醋酸銦以探討銦添加量對TFT元件電性質之影響，實驗結果發現導通電流（On Current）和截止電流（Off Current）隨著銦摻雜濃度的增加而增加，並有往負電壓偏移的現象；當In/Zn成分比例為5 mol.%時，TFT元件呈現最佳之載子遷移率（Mobility，） = 0.595 cm2/Vsec、電流開關比（On/Off Ratio） = 1.1×106、臨界電壓值（Threshold Voltage，VTH） = 4.33 V、次臨界擺幅（Subthreshold Swing，S.S.） = 5.11 V/decade。

關鍵字

薄膜電晶體；氧化物；濕式製程

並列摘要

This study employs the polyol process to prepare the indium-doped zinc oxide (IZO) thin films to serve as the active channel layer of thin-film transistor (TFT). By using diethylene glycol (DEG) as the solvent/chelating agent, zinc acetate salt and indium acetate salt as the Zn and In sources and polyvinylpyrrolidone (PVP) as the protective agent, we successfully synthesized the IZO precursor via a 180C thermal process for 2 hrs. By centrifugating the sediment from supernatant and further dispersing it in pentanol, the IZO layers were prepared by the spin-coating method in conjunction with a post annealing in air ambient. The parameters subjected to investigation include the reaction temperature and time, water addition amount, annealing temperature and time so as to explore their effects on microstructures and physcial properties of IZO thin films. Consequently, the IZO layer was implanted in TFT devices and the electrical performance of devices was evaluated. The effects of In content on the electrical properties of IZO-TFT were also investigated. Analytical results indicated that the on current and off cureent increase with the increase of In content and the transfer characteristic profiles tends to shift to the negative bias side. At In/Zn composition ratio = 5 mol.%, the TFT device exhibited the best performance with the carrier mobility () = 0.595 cm2/Vsec, on/off ratio = 1.1×106, threshold voltage (VTH) = 4.33 V and subthreshold swing (S.S.) = 5.11 V/decade.

並列關鍵字

TFT ； Oxide ； Wet

參考文獻

[1]S. Uchikoga, “Future trend of flat panel deisplays and comparison of its driving methods”, Proc. IEEE Int. Symp. Power Semicond. Devices ICs, 4-8 (2006), p. 1-5

[2]S. C. Chang, “The TFT-LCD industry in Taiwan: competitive advantages and future developments”, Technol. Soc., 27(2005), p.199-215.

[3]A. R. Hepburn, J. M. Marshall, and C. Main, “Metastable defects in amorphous-silicon thin-film transistors”, Phys. Rev. Lett., 56(1986), p. 2215-2218.

[4]M. J. Powell, “The physics of amorphous-silicon thin-film transistors”, IEEE Trans. Electron. Dev., 36(1989), p. 2753-2763.

[5]T. Kamiya, K. Nomura, and H. Hosono, “Origins of high mobility and low operation voltage of amorphous oxide TFTs: electronic structure, electron transport, defects and doping”, J. Display Technol., 5(2009), p. 468-483.

國際替代計量

含銦鋅氧化物之薄膜電晶體之濕式製程研究

全文下載

主題瀏覽