濺射成長ITO/金屬/ITO多層透明導電膜之特性研究

The characteristics of ITO/metal/ITO multilayer transparent conductive films by sputtering

楊峻銘(Chun-ming Yang)

指導教授 ： 林天財

崑山科技大學/工程學院/電機工程研究所/碩士(2005年)

https://doi.org/10.6828/KSU.2005.00055

摘要

透明導電膜 ( transparent conducting films ) 指的是在可見光範圍內具有高穿透性，且具有良好導電性之薄膜。由於具特別的光性質及電性質，可應用在諸多領域。為了使其導電性和光穿透率更加優良，本研究主要以DC磁控濺鍍法在玻璃基板上配合基板旋轉來沉積透明導電膜（ITO）以及添加夾層金屬（Ag及Ti）使形成多層膜結構（ITO/metal/ITO），探討其對薄膜結構與光電特性之影響。
研究結果顯示，增加夾層金屬Ag及Ti對其整體之電阻率有下降之趨勢，因為多層膜結構可視為電阻並聯效應，故ITO與金屬薄膜並聯後，整體之導電機制以金屬薄膜為主，故達到降低其電阻率之目的。其中ITO/Ag/ITO最佳參數之電阻率為1.57x10-5 Ω-cm，平均可見光穿透率約為85%左右。而ITO/Ti/ITO最佳參數之電阻率為1.7x10-4 Ω-cm，平均可見光穿透率約為65%左右。
退火結果顯示，ITO熱處理溫度在400℃以上時，開始有結晶相產生，而電阻率因為其熱處理所提供之動能，使晶格重新排列使缺陷消除，故電阻率呈現下降趨勢，且增加光穿透率，最佳數據電阻率為1.22x10-4 Ω-cm，平均可見光穿透率約為92%左右。而ITO/Ag/ITO在500℃退火時，薄膜有ITO結晶相產生，但並未發現Ag之結晶相。不過熱處理所提供之動能，依舊有達到使晶格重新排列修補缺陷之效果，所以也降低了薄膜電阻率和保持可見光高穿透率，其最佳數據電阻率為1.22x10-5 Ω-cm，平均可見光穿透率約為90%左右。

關鍵字

多層膜 ； 氧化銦錫 ； 濺鍍 ； 熱處理 ； 電阻率 ； 光穿透率

並列摘要

Transparent conducting films has high properties of transmittance and conductance in the visible range. Because of its special optical and electrical properties, it is used for many application. In order to increase the transmission and resistivity, this thesis was mainly used DC magnetron sputtering method with substrate spin to deposit ITO thin films. The different kinds of metals (Ag and Ti) was added to form ITO/metal/ITO multilayers, then the influence of electrical, optical and structural characteristics were discussed.
The experimental results showed, the total resistivity decreased when the metals of Ag and Ti added , because multilayers structure can regard as a effect of parallel resistance circuit. The total resistance was very low because of high conductive metal film in parallel structure, therefore, the purpose of reduce resistivity was achieved. Among the best ITO/Ag/ITO resistivity parameter was 1.57x10-5 Ω-cm, the average optical transmittance was beyond 85%. The ITO/Ti/ITO showed a very low resistivity of 1.7x10-4 Ω-cm and the average transmittance of 65% in as deposited.
At post-annealing experimental, when the ITO annealing temperature exceed 400℃, the film was crystallized. The annealing process provide thermal energy to crystallize and eliminate defects, so the resistivity decreased, and the transmittance increased. The best result was the resistivity of 1.22x10-4 Ω-cm and the average transmittance beyond 92%. When the ITO/Ag/ITO films annealed at 500℃, the ITO layer was crystallized but crystalline of Ag was not found. The annealing process still provide the thermal energy to make the effect of crystallization and eliminating defects, so the resistivity decreased and the high transmittance kept. The best result was the resistivity of 1.22x10-5 Ω-cm and the average transmittance beyond 90%.

並列關鍵字

ITO ； multilayer ； resistivity ； annealing ； transmittance ； sputtering

參考文獻

[3] Co Watkins-Johnsons,“Hihgly Conductive and Transparent Films of Tin and Fluorine Doped Indium Wxide Produced by APCVD”,Thin Solid Films, 221 (1992) pp.166.

[4] F. Zhu, C. H. A. Huan, K, Zhang and A. T. S. Wee, “Investigation of Annealing Effects on Indium Tin Oxide Thin Films by Electron Energy Loss Spectroscopy”,Thin Solid Films, 359 (2000) pp.244.

[5] R. B. H. Tahar, T. Ban, Y. Ohya and Y. Takahashi, “Electronic Transport in Tin-doped Indium Oxide Thin Films Prepared by Sol-gel Technique”,J. Appl. phys., 83 (1998) pp.2139.

[6] F. Zhang, C. Zhu, H. A. Huan and A. T. S. Wee, “Effect of Hydrogen Partial Pressure on Optoelectronic Properties of Indium Tin Oxide Thin Films Deposited by Radio Frequency Magnetron Sputtering Method”,J. Appl. Phys. 86 (1999) pp974-980.

[7] L. H. Meng and M. P. dos Santos, “Properties of Indium Tin Oxide (ITO) Films Prepared by r.f. Reactive Magnetron Sputtering at Different Pressures”,Thin Solid Films, 303 (1997) pp.151.