氧化鋅薄膜之微結構與奈米機械特性研究

Abstract

本研究利用射頻磁控式濺鍍(RF-sputtering)法於矽(100)基材上沉積高品質氧化鋅薄膜，在實驗中改變濺鍍功率(50、100、150、200、以及300 W)來觀察其對氧化鋅薄膜表面形貌、晶格結構、及奈米機械性質的影響。實驗中以掃瞄式電子顯微鏡(SEM)、原子力顯微鏡(AFM)來觀察薄膜之表面形貌與表面粗糙度，再以X光繞射儀(XRD)以及穿透式電子顯微鏡(TEM)分別觀察氧化鋅薄膜之結晶結構與微區結構。最後於不同沉積功率參數的氧化鋅薄膜應用奈米壓痕系統測試其機械性質，目的在於瞭解氧化鋅薄膜之硬度與楊式係數等機械特性的表現。 從SEM與AFM所得到的實驗結果可以發現沉積於矽基材上之氧化鋅薄膜，其表面形貌會隨著濺鍍功率的提升而趨於平坦化。觀察X-Ray的分析結果，氧化鋅薄膜在34度附近有較明顯之散射峰值，此為氧化鋅(002)晶面。在奈米機械特性方面，是利用奈米壓痕技術得到薄膜的硬度與楊氏係數，從實驗結果可以得知，薄膜之機械特性除了受到濺鍍功率大小的影響外，還會受到基材效應的影響而有所變化。

In this study, the ZnO thin films were deposited onto Si (100) substrate by ratio frequency sputtering with various RF power at 50, 100, 150, 200, and 300 W and the surface morphologies, crystalline structural, and nanomechanical properties of ZnO thin films were examined. Surface roughness and surface morphologies of ZnO thin films were observed by scanning electronic microscope (SEM) and atomic force microscope (AFM). Characteristics of crystallization and microstructure were analyzed by X-Ray diffractometer (XRD) and transmission electron microscope (TEM) respectively. Eventually, the nanomechanical properties of ZnO thin films like hardness and Young’s modulus were explored by nanoindentation technique. The patterns of SEM and AFM revealed that the surface became smoother as the RF power increased. The deposited film featured a polycrystalline nature, with only (002) peaks of hexagonal ZnO at 34°. In nanomechanical property aspect, the hardness and Young’s modulus could be obtained by nanoindentation technique. Experimental result demonstrated that the nanomechanical properties influenced by not only RF power but also substrate effect.