射频溅射功率对Mn-Co-Ni-O薄膜结构与性能的影响

Effect of Radio Frequency Sputtering Power on the Structure and Properties of Mn-Co-Ni-O Thin Films

采用射频磁控溅射技术在硅衬底上制备了锰钴镍氧(Mn-Co-Ni-O,MCNO)薄膜并进行了后退火处理。利用X射线衍射、扫描电子显微镜、光学测试仪器等测试手段对晶体结构、表面形貌及光学性能进行表征。分析了不同射频溅射功率(60~100 W)对MCNO薄膜表面微观形貌、晶体结构和光学性能的影响。结果表明,在60~90 W下获得的薄膜表面致密且均匀,但在100 W下获得的MCNO薄膜表面晶粒尺寸显著增大。物相分析表明,采用射频磁控溅射沉积的MCNO薄膜主要为尖晶石结构,溅射功率对薄膜结晶质量和择优取向具有显著影响,在80 W下获得的MCNO薄膜结晶质量最佳。同时,拉曼光谱测试也表明该MCNO薄膜表现出最强的Mn^(4+)—O对称弯曲振动和最小的压应力。紫外-可见-近红外光谱分析表明,MCNO薄膜的吸光范围主要在可见光-近红外波段,在80~90 W溅射功率下获得的MCNO薄膜在近红外波段表现出更强的吸收峰。射频溅射功率的改变会影响薄膜的厚度和结晶质量,从而对薄膜的光学带隙起到调控作用。光致发光光谱测试不同溅射功率下薄膜的缺陷峰发光强度,且在功率为80 W时沉积的薄膜具有最强紫外发射峰,表明改变溅射功率能够有效改善薄膜缺陷及提高晶体质量。

In this study,manganese-cobalt-nickel-oxide(Mn-Co-Ni-O,MCNO)thin films were prepared on silicon substrates by radio frequency(RF)magnetron sputtering and post-annealing.The crystal structure and surface morphology of the thin films were characterized by X-ray diffraction and scanning electron microscopy,and their optical properties were tested and analyzed by optical testing instruments.The effect of RF sputtering power(60~100 W)on the surface morphology,crystal structure and optical properties of MCNO thin films were analyzed.The surfaces of the films obtained under 60~90 W were dense and uniform,but the surface grain size of the MCNO thin films obtained under 100 W increases significantly.The phase analysis shows that the MCNO thin films deposited by RF magnetron sputtering are mainly spinel structures,and the sputtering power has a significant effect on the crystal quality and preferred orientation of thin films.The crystal quality of the MCNO thin films obtained under 80 W is the best.At the same time,the Raman spectroscopy test also shows that the MCNO thin film exhibits the strongest Mn^(4+)-O symmetrical bending vibration and the smallest compressive stress.Ultraviolet-visible-near-infrared spectroscopy analysis show that the absorption range of MCNO thin films is mainly in the visible-near-infrared band,and the MCNO thin films obtained under the sputtering power of 80~90 W show stronger absorption peaks in the near-infrared band.The change of the RF sputtering power can affect the thickness and crystalline quality of the thin film,thereby regulating the optical band gap of the thin film.The luminescence of the defect peaks at different sputtering powers was measured by photoluminescence spectroscopy,and the thin films deposited at 80 W have the strongest UV emission peaks,demonstrating that varying the sputtering power can effectively improve the defects and crystal quality.