經表面處理之氧化銦錫/氧化鋅蕭特基二極體之研究

本篇論文主要研究以垂直結構成長之氧化鋅薄膜蕭特基接面元件之特性。薄膜以紅外光波段之二氧化碳雷射蒸鍍成長法長成，氧化鋅薄膜皆以加熱之雙氧水為表面處理。至於金屬接面，我們選擇室溫成長之氧化銦錫，因其同時具備高透光率（可見光波段）與高導電性之雙重優點。實驗主要分兩個部分。首先，以600 °C成長之氧化鋅，加以不同時間的雙氧水處理。經電流-電壓曲線分析，結果發現經雙氧水處理之元件，可達成原先無法達成之蕭特基整流效應。而經比較，以1200秒處理之氧化鋅薄膜，其元件效果最佳。而經由光激發螢光（PL）與電子顯微鏡（FESEM）實驗，我們發現其整流效果之改善來自於表面缺陷之減少，以及過氧化鋅絕緣層之成長。為進一步了解雙氧水對氧化鋅表面之影響，我們以雙氧水處理了不同溫度成長之氧化鋅薄膜。以掠角X光量測結果發現，低溫成長之氧化鋅薄膜，有氧化鋅與過氧化鋅同時成長的可能。電子顯微鏡的結果亦可看出，雙氧水產生之表層氧化對低溫成長之薄膜，影響確實較高溫成長之薄膜顯著。而經X射線光電子能譜（XPS）數據更發現雙氧水對高溫成長之薄膜，主要以處理缺陷為主；而對低溫成長之薄膜，則主要以氧化為主。經電壓-電流曲線分析，以400 °C成長之氧化鋅元件特性最佳。

關鍵字

氧化鋅；氧化銦錫；蕭特基二極體；雙氧水；光電子能譜

並列摘要

In this dissertation, a transparent, efficient vertical structure poly-ZnO ultraviolet Schottky-type photodiode with indium-tin-oxide (ITO) as a metallic contact layer is fabricated on ITO-coated glass substrates by cw CO2 laser evaporation. Hydrogen peroxide (H2O2) is used as surface treatment for ZnO. Different temperature grown samples as well as samples under different treatment durations were examined to find out the mechanism of H2O2 on ZnO. For ZnO samples under different H2O2 treatment durations, results showed that dramatic improvement in the rectifying behavior can be achieved. For films grown under 600 °C with H2O2 treated for 1200 seconds, the fitted Schottky barrier height (SBH) from I-V measurements were as high as 1.16 eV, the ideality factor (n) 2.31, and a leakage current 3.1×10-7 A at -3 V bias. Also from the photoluminescence (PL) study we found that green-band emissions, which came from the defects of ZnO, especially zinc interstitials and oxygen vacancies, were greatly reduced with the increase of H2O2 processing time. Also these data suggest gradual oxidation on ZnO surface. To further investigate the mechanisms between H2O2 and ZnO samples, films grown under different temperatures (600 °C, 400 °C, 200 °C, and room temperature) were examined by several instruments. By grazing incidence X-ray diffraction (GIXRD) research, diffraction peak (111) of ZnO2 was found on films grown under 200 °C. The investigations by field-emission scanning electron microscope (FESEM) and X-ray photoelectron spectroscopy (XPS) analysis clearly reveal oxidation, and an interfacial ZnO2 layer covers the ZnO surface through H2O2 treatment. I-V measurements indicated that the ideality factor and the Schottky barrier height improved with increasing shunt resistance. Trade-off between film quality and the degree of oxidation showed that 400 °C grown sample with 1200 sec H2O2 treatment gives the best diode characteristics.

並列關鍵字

ZnO ； ITO ； Schottky diode ； hydrogen peroxide ； XPS

參考文獻

Chapter 1:

1. M. Gawlicki and D. Czamarska, “Effect of ZnO on the hydration of Portland cement,” J. Therm. Anal. 38 (1992) 2157.

3. L. Meng, L. Zheng, L. Cheng, Z. Yao, G. Li and S. Bernik, “Enhancement of the electrical stability of ZnO varistors by a novel immersion process,” J. Am. Ceram. Soc. 94 (2011) 2939.

4. H. Feng, Z. Peng, X. Fu, Z. Fu, C. Wang, L. Qi and H. Miao, “Effect of SnO2 doping on microstructural and electrical properties of ZnO-Pr6O11 based varistors ceramics,” J. Alloys Compd. 509 (2011) 7175.

5. F.-C. Huang, Y.-Y. Chen and T.-T. Wu, “A room temperature surface acoustic wave hydrogen sensor with Pt coated ZnO nanorods,” Nanotechnology, 20 (2009) 065501.

國際替代計量

經表面處理之氧化銦錫/氧化鋅蕭特基二極體之研究

全文下載

主題瀏覽