PECVD制备富硅氮化硅薄膜的工艺条件及其性质的研究

Study on Technological Conditions and Properties of Si-rich Silicon Nitride Thin Films Prepared with PECVD

采用等离子体增强化学气相沉积法(PECVD)以SiH4和N2为反应气体,分别在射频功率、硅烷稀释度[SiH4/N2]、衬底温度为变量的情况下制备了富硅氮化硅薄膜材料,利用X射线衍射谱(XRD)、傅里叶变换红外谱(FTIR)、紫外-可见光吸收谱(UV-Vis)对薄膜材料进行了表征,并研究了薄膜材料的微结构和晶化状况、光学特性等。实验结果表明,所沉积薄膜都为富硅的非晶氮化硅材料,改变射频功率、硅烷稀释度和衬底温度可以控制氮化硅薄膜中N元素的含量、光学带隙的大小和薄膜的折射率,并制备出最适宜富硅氮化硅薄膜,为进一步退火析出硅量子点奠定了基础。

Silicon nitride thin films were fabricated by plasma-enhanced chemical vapor deposition （PECVD） using silane and nitrogen with the variables of radio frequency power, silane dilution ratio [ SiH4/N2 ] and substrate temperature. X-ray diffraction, Fourier transform infrared spectroscopy and UV-Vis spectroscopy were used to characterize the thin films, and researched microstructure, crystallization condition and optical property of the thin films. The experiment results indicated that the thin films are amorphous structure of Si3N4, the control of nitrogen content, optical band gap and refractive index in amorphous Si3 N4 thin films can be realized by the regulation of radio frequency power, silane dilution ratio and substrate temperature, deposition products are the best Si-rich silicon nitride thin films. The results established a solid foundation for further annealing and separation of silicon quantum dots.