为了探究氧化层对金属薄膜表面等离子体共振(SPR)特性的调制作用，实验采用直流磁控溅射技术，通过控制沉积功率和沉积时间制备不同厚度的金属铝基薄膜，而后调控退火时间和温度得到相应的铝/氧化铝(Al/Al₂O₃)复合薄膜。采用X 射线衍射仪(XRD)、原子力显微镜(AFM)、紫外-可见-近红外分光光度计及拉曼光谱仪分别表征样品的结构、表面形貌及SPR 特性。XRD 测试结果表明，随着金属铝基薄膜厚度的增加，Al/Al₂O₃ 复合薄膜由非晶态转变为较低表面能方向择优生长，薄膜结晶质量提高。其吸收光谱在220 nm 附近处出现由双层复合薄膜SPR 吸收峰，830 nm 附近的峰对应金属铝膜的本征吸收峰。以罗丹明B 为例的拉曼光谱测试结果表明，拉曼散射强度随着铝薄膜厚度增加表现为先增强后减弱的趋势，当铝膜厚度为14.5 nm 时，表面增强拉曼散射(SERS)效果最显著。实验结果表明，氧化铝膜层对不同厚度的金属铝基薄膜的SPR 特性有很好的调制作用，氧化铝化学性质稳定，对样品起到很好的保护作用。

In order to investigate the modulation of the surface oxide layer on the surface plasmon resonance (SPR) properties of the metal thin films, Al metallic films are deposited with different thicknesses by DC magnetron sputtering by controlling the deposition power and deposition time. The as-deposited films are annealed to fabricate Al/Al₂O₃ composite films by regulating the annealing time and temperature. The structures, morphology and SPR properties of the Al/Al₂O₃ composite films are investigated by X-ray diffraction (XRD), atomic force microscope (AFM), spectro photometer and Raman spectroscopy, respectively. XRD results show that the phases of Al/Al₂O₃ composite films vary from amorphous to polycrystalline with a preferential orientation with the thickness increasing. Optical absorption spectra show that two peaks which correspond to the SPR absorption peak near 220 nm and the intrinsic absorption peak metal aluminum film near 830 nm. Raman spectrum reveals that the surface enhanced Raman scattering (SERS) intensity of Rhodamine B increases with the increasing thickness up to 14.5 nm and then decreases with the thickness further increasing. The results demonstrate that Al₂O₃ film has the capability to modulate the SPR with good properties.