利用電漿輔助式化學沉積法成長氧化鋅薄膜

Fabrication of ZnO (002) thin films grown by PECVD

郭育安(Yu-An Kuo)

指導教授 ： 魏大華

國立臺北科技大學/機電學院/機電整合研究所/碩士(2010年)

https://doi.org/10.6841/NTUT.2010.00588

摘要

本研究是利用電漿輔助式化學沈積法(PECVD)，分別以二乙基鋅(DEZn)及二氧化碳(CO2)之混合氣體為鋅及氧元素之反應源，在Si(100)基板與玻璃基板上製備纖鋅礦型式(Wurtzite)具有c軸(0002)優選取向之氧化鋅薄膜結構。本論文中分別操控的製程參數範圍：二氧化碳的氣體流量(6~20 sccm)、基板溫度(250~450 oC)、射頻(RF)功率(30~70 W)與製程壓力(500~1000 mTorr)，並探討在不同製程參數下對於形成(0002)織構的氧化鋅薄膜之影響。
由實驗結果顯示：於製程壓力500 mTorr、RF功率60 W、基板溫度400 oC和CO2流量為20 sccm時，所沉積之氧化鋅薄膜在Si基板及玻璃基板上有較佳之c軸(0002)織構能力，同時XRD之半高寬(full width at half maximum, FWHM)值可達 0.151o，並具有優異的紫外光發光效率。另外隨RF功率與基板溫度增加時，在半高寬的部份會隨之遞減，這也表示氧化鋅薄膜要沿著c軸方向做成長，給予額外的能量是非常重要的。另一方面，隨著二氧化碳流量、RF功率與基板溫度的增加，其表面粗糙度也隨之增加。而從光致螢光光譜儀(Photoluminescence Spectrophotometer, PL)與拉曼光譜(Raman spectra)分析得知：在本質紫外光波段380 nm左右和波數437 cm-1的位置有明顯的頻譜訊號，證實為氧化鋅相。另外，在UV-VIS穿透光譜圖中，於可見光區段(400~800 nm)具有高穿透率(達 85%)，同時表示未來極具潛力應用於顯示器和光電元件用途。

關鍵字

氧化鋅 ； 電漿輔助式化學沉積系統 ； c軸(0002)優選取向 ； 穿透率 ； 發光

並列摘要

The wurtzite ZnO thin films with c-axis (0002) preferred orientation have been successfully grown on the Si(100) and glass substrates by plasma enhanced chemical vapor deposition (PECVD) using diethylzinc (DEZn) liquid and carbon dioxide (CO2) gas as the Zn and O sources, respectively. This thesis is focused on the synthesized conditions for forming (0002) textured ZnO films by varying the fabrication parameters during film growth process. The changed parameters in the synthesized processes of ZnO phase including the CO2 gas flows (6~20 sccm), substrate temperature (250~450 oC), radio frequency (RF) power (30~70 W), and working pressure (500~1000 mTorr). The optimized conditions for fabricating c-axis ZnO (0002) epitaxial films with the narrow full width at half maximum (FWHM) value of about 0.151o onto silicon and glass substrates are at working pressure of 500 mTorr, substrate temperature of 400 oC, RF power of 60 W, and CO2 flow of 20 sccm, respectively. The FWHM values decrease with increasing the working power and substrate temperature, indicating the extra energy is important for forming c-axis alignment of ZnO films. On the other hand, the surface roughness increases with increasing the values of CO2 flow, RF power, and substrate temperature, respectively. From the photoluminescence (PL) and Raman spectra, the typical intrinsic UV-band emitted peak is appeared and located at about 380 nm and 437 cm-1, indicating the ZnO phase formed. The transmission spectrum shows the highly transmissive ability (over 85%) in the visible region (400~800 nm) that shown the possibility for the future applications of display and optoelectronic devices.

並列關鍵字

ZnO ； plasma enhanced chemical vapor deposition ； c-axis (0002) preferred orientation ； transmission ； luminescence

參考文獻

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