射频磁控溅射法制备氮化硅基ZnO薄膜的光致发光性能研究

Photoluminescence of Silicon Nitride-Based ZnO Thin Film Developed with RF Magnetron Sputtering

氮化硅薄膜因其耐腐蚀性、高温稳定性和良好的机械强度等优点,被广泛用作透射电子显微镜(TEM)、扫描电子显微镜(SEM)、原子力显微镜(AFM)、X射线光电子能谱仪(XPS)、能量色散X射线光谱仪(EDX)等的表征实验承载体。特别是,SiN可作为SEM观察时的低扰背景。然而SiN薄膜较差的荧光性制约了其进一步在荧光器件中的广泛应用。为了进一步提高SiN薄膜窗口的荧光效率,实验研究中采用了射频磁控溅射技术在SiN_x薄膜衬底上成功制备出系列ZnO薄膜,并分别进行了氮气氛非原位退火和原位退火处理。然后利用原子力显微镜(AFM)、扫描电子显微镜(SEM)、拉曼光谱仪(Raman)对薄膜的微结构和光致发光(PL)性能进行了研究,并系统研究了所制备薄膜的发光情况。实验研究结果表明,镀膜后荧光强度普遍提升,退火促进晶粒进一步熟化生长、结晶性能大幅提升、晶界减少,且退火方式对射频磁控溅射法制备的ZnO/SiN复合薄膜的微结构和发光性能有显著影响。与SiN_x薄膜相比,未退火的ZnO/SiN_x薄膜和N_2气氛非原位退火的ZnO/SiN_x薄膜在380nm附近的带边本征发射强度分别提高了7.7倍和34.0倍以上。与非原位退火处理的薄膜相比,原位退火处理的ZnO/SiN_x薄膜具有更多的氧空位缺陷,因此表现出更强的可见光波段PL强度,在425~600nm的可见光波段表现出更高的光致发光能力。这些结果有助于优化氮化硅基ZnO荧光薄膜的制备参数。

Owing to its merits of high corrosion resistance,high temperature stability as well as good mechanical strength etc.,silicon nitride membrane（SiN）has been widely used as the experimental carrier of transmission electron microscope（TEM）,scanning electron microscopy（SEM）,atomic force microscope（AFM）,X-ray photoelectron spectroscopy（XPS）,energy dispersive X-Ray spectroscopy（EDX）and other characterization.In particular,SiN can be used as a low disturbing background for SEM observation.However,the poor luminescent property of SiN thin film has restricted its wide application in fluorescent devices.In order to enhance the fluorescence efficiency of silicon nitride membrane,a series of ZnO films were prepared on a SiNx film substrate with radio frequency magnetron sputtering（RF magnetron sputtering）technology during the experiment.Samples were then non-situ and in-situ annealed in nitrogen atmosphere,respectively.Then,atomic force microscope（AFM）,scanning electron microscopy（SEM）and Raman spectroscopy（Raman）were applied to study the microstructure and photoluminescence（PL）properties of the prepared films.This paper also systemically studies the luminescence of the prepared thin films.The results show that,luminescent intensity increases after sputtering,while annealing further promoted the grain growth,a substantial increase in crystallization behavior and a decrease in grain boundary.The microstructure and luminescence properties of ZnO/SiN thin films prepared by RF magnetron sputtering were significantly influenced by annealing method.Compared with the SiNx film,near the band edge of the intrinsic emission intensity（about 380nm）of untempered ZnO/SiNxfilms and N2 atmosphere exsitu annealed ZnO/SiNxfilms were increased by more than 7.7times and 34.0times.Compared with non-situ annealed films,insitu annealed films contained more oxygen vacancy defects,thus showing a stronger visible light PL intensity.In-situ annealed films exhibited a higher photoluminescence capacity during the wavelength from 425 to 600nm of visible light.These results can help to optimize the preparation parameters of silicon nitride based ZnO fluorescent films.