SiO2-TiO2溶胶-凝胶薄膜的激光致密化研究

为了研究激光直写技术在薄膜器件成型工艺中的应用,采用波长为1.07μm的连续光纤激光器对SiO2/Si基表面SiO2-TiO2多孔溶胶-凝胶薄膜进行致密化的方法,得到了激光功率密度对薄膜收缩率的影响规律以及热处理温度对薄膜的激光致密化功率密度阈值和厚度变化的影响结果.结果表明,薄膜收缩率随着激光功率密度的增加而增大.薄膜热处理温度越高,激光致密化功率密度阈值越高,达到薄膜致密化极限需要的激光能量越大.激光致密化机制是通过硅衬底吸收激光能量,然后以热传导的形式加热溶胶-凝胶疏松薄膜,实现薄膜致密化.

Study on the densification of SiO2-TiO2 Sol-Gel films by laser irradiation

In order to study the application of laser direct writing technology in the area of thin film elements rapid fabrication,the densification of SiO2-TiO2 porous sol-gel films on SiO2/Si wafer was performed by means of a continuous fiber laser with the wavelength of 1.07μm. The effect of laser power density on the shrinkage of the film was investigated. The thresholds of laser power density and the change of thickness of films under different preheated temperatures were discussed.Finally,the mechanism of laser densification of the SiO2-TiO2 films was also analyzed. The experimental results demonstrate that the shrinkage of films increases with the laser power density. The thresholds of laser power density will increase with increasing temperature in the process of laser densification. The energy of induced laser beam is absorbed by Si substrate instead of Sol-Gel film. The mechanism of laser densification of the SiO2-TiO2 films is mainly based on the shrinkage of nanon-scale pore due to the energy transfer from Si wafers.