利用射頻磁控共濺鍍法成長氧化鋅摻雜鉬透明導電膜之特性研究

Preparation of transparent conducting ZnO doped with Molybdenum films by RF magnetron sputtering

陳冠勳(Guan-Syun Chen)

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(2009年)

摘要

氧化鋅薄膜有顯著C軸優選方向，但其電阻值卻偏高，要獲得最佳氧化鋅的導電性，除了材料本身氧空缺及鋅間隙原子提供電子外，也藉由不同摻雜物的取代來獲得額外的電子。本研究計畫利用高價元素摻雜氧化鋅薄膜，在低的?狟蠵@度下可得高載子濃度，因此薄膜有較高的載子遷移率。
在本研究裡，對氧化鋅摻雜鉬進行材料特性分析。首先利用RF射頻濺鍍法進行氧化鋅及鉬雙靶共濺鍍，成長氧化鋅摻雜鉬透明導電膜於玻璃基板上。研究中改變濺鍍功率、沉積時間及基板溫度，求得最佳光電特性的薄膜，再將最佳製程參數進行熱處理，利用不同的退火方式，改變退火溫度及退火氣氛，期許能更進一步改善薄膜的導電率及透光率。結果得知ZnO摻雜Mo薄膜，皆出現 (002) C軸優選方向，經退火處理過後薄膜結晶優選方向更加明顯。薄膜光學能隙(Eopt)隨鉬濺鍍功率增加而增加，有能隙寬化現象產生。由於在氫氣中退火時，氫與氧起反應還原作用，使薄膜氧空缺增加以及作為淺層施體能階摻雜，使載子濃度大幅提升，所以在氫氣氛下退火300℃時得到最佳電性，載子濃度為1.29x1020cm-3、載子遷移率為7.94cm2/vs，電阻率為6.09x10-3Ω-cm，平均穿透率為80.85%。

關鍵字

氧化鋅 ； 共濺鍍 ； 氫氣氛退火

並列摘要

The Zinc oxide films have a strong c-axis preferred orientation, but the conduction of undoped ZnO films have high resistivity. In order to obtain the best electric conductivity of zinc oxide, the electron carriers are not only offered by oxygen vacancies and Zn interstitial atoms but also by the replacement of impurity doping. In this study, we used a high valence element to add into ZnO films, therefore, a high carrier concentration is able to obtain at lower concentration of dopant, and the films show high carrier mobility.
In this research, we analyzed the characteristics of ZnO doped with molybdenum, which was grown by radio frequency magnetron co- sputtering on glass substrates. In this experiment, the parameters were changed such as target powers, deposition time and substrate temperature to obtain the best photoelectric characteristics of thin films. The as-deposited films were annealed with different annealing methods, and treated at various temperature and annealing atmosphere. The annealing purpose is expect to improve the electric-optical properties of films. The results show all ZnO:Mo films have (002) c-axis preferred orientation. The (002) degree of preferred orientation is more intensive after annealing. The optical band gap increases with increasing the power of Mo target, indicating the optical band gap of film is broaden. Hydrogen plays a role to reduct oxide in hydrogen post-annealing, hence the oxygen vacancies increase and plays a shallow donor doping. Due to the carrier concentration improved at H2 post-annealing of 300℃, the best value, the carrier concentration of 1.29X1020cm-3, the mobility of 7.94cm2/vs, the lowest resistivity of 6.09X10-3Ω-cm and the average transmittance of 80.58% were obtained.

並列關鍵字

Zinc oxide ； co-sputtering ； hydrogen post-annealing

參考文獻

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