- 學位論文
塑膠基板上濺鍍ZnO：Al薄膜探討ZnO介層與氫電漿處理對光電特性之影響
The effect of ZnO buffer layers and hydrogen plasma post-treatment for the optoelectronic properties of ZnO:Al films deposited on plastic substrates by sputtering
摘要
本研究以射頻磁控濺鍍成長氧化鋅鋁薄膜於塑膠基板上，藉由改變基板溫度與氧化鋅之介層厚度，獲得最佳光電特性薄膜，再進行氫電漿熱處理，藉由氫電漿熱處理改善成長於塑膠基板之氧化鋅鋁薄膜之光電特性。 經由實驗結果得知，基板加熱有助於氧化鋅鋁薄膜繞射峰(002)的成長，但製程時間過長會使電性不佳且光穿透率降低，故當射頻功率125W、沉積時間20min、基板溫度100℃，可得最佳之光電特性，電阻率為1.2×10-1Ω-cm，載子濃度為2.04×1020cm-3，遷移率為0.264cm2/Vs，平均光穿透率91%。 經由實驗結果得知，當加入適當厚度的氧化鋅介層，有助於繞射峰(002) 的成長且可改善光電特性，當加入50nm的氧化鋅介層，可得最佳之光電特性，電阻率為3.87×10-2Ω-cm，載子濃度為1.14×1021cm-3，遷移率為0.574cm2/Vs，平均光穿透率91%。 氫電漿熱處理方面，本實驗射頻功率為100W，氫電漿熱處理時間為20分鐘可得到最佳的光電特性，低壓時由於平均自由路徑長，使得氧化鋅鋁薄膜為電漿轟擊熱處理的效果，其最佳光電特性，電阻率為4.62×10-2Ω-cm，載子濃度為1.73×1020cm-3，遷移率為0.858cm2/Vs，平均光穿透率87%；高壓時由於平均自由路徑短，使得氫原子起還原作用，使薄膜氧空缺增加，載子濃度提升，而電阻率為1.73×10-2Ω-cm，載子濃度為1.62×1020cm-3，遷移率為0.862cm2/Vs，平均光穿透率91%。
並列摘要
In this study, we used RF magnetron sputtering to grow aluminum doped ZnO films on polycarbonate substrates. The films were processed by changing substrate temperature and thickness of ZnO interlayer to get appropriate properties of films. After deposition, the AZO samples were treated in hydrogen plasma. The plasma treatment could further improve the AZO properties such as transmittance and resistivity. The preferred (002) orientation of AZO film increases with increasing substrate temperatures, but when the deposition time is too long the electrical and optical properties will become worse. The best properties were obtained at resistivity of 1.2×10-1Ω-cm, carrier concentration of 2.04×1020cm-3, mobility of 0.264cm2/Vs and average transmittance of 91 %. The process condition was carried out at that AZO power is 125W, deposition time is 20min and substrate temperature is 100℃. The preferred (002) orientation and opto-electrical properties of AZO film were improved by introducing a ZnO interlayer. The best properties shown resistivity of 3.87×10-2Ω-cm, carrier concentration of 1.14×1021cm-3, mobility of 0.574cm2/Vs and average transmittance of 91 % were processed with 50nm ZnO interlayer. In hydrogen plasma, we got the best properties of films at plasma power of 100W and processing time of 20min. The heating effect by ion bombardment into AZO film was dominated in low pressure as well as longer mean free path, therefore the properties were improved such as resistivity of 4.62×10-2Ω-cm, carrier concentration of 1.73×1020cm-3, mobility of 0.858cm2/Vs and the average transmittance of 87%. In hydrogen plasma, hydrogen can increase oxygen vacancies as well as increasing carrier concentration. The reduce effect by hydrogen is dominated in high pressure as well as shorter mean free path, therefore, the properties were improved such as resistivity of 1.73×10-2Ω-cm, carrier concentration of 1.62×1020cm-3, mobility of 0.862cm2/Vs and the average transmittance of 91%.