用等离子体增强化学气相淀积制备了Ge掺杂SiO2薄膜,并对薄膜进行了不同温度的退火处理。采用棱镜耦合仪、原子力显微镜和傅里叶变换红外光谱分析技术研究了不同退火温度对Ge掺杂SiO2薄膜性质的影响。通过1 100℃退火处理后,正的折射率变化量和负的体积变化量随着GeH4流量增加而增大,Ge-O-Ge键增多;而通过900℃退火处理后,折射率没有随着GeH4流量增加而增大;薄膜的表面粗糙度随着退火温度升高而降低。研究结果表明,SiO2薄膜中Ge掺杂过量,其折射率反常下降;通过1 100℃退火处理后,折射率随着GeH4流量增加而增大,折射率的增大主要是由于薄膜密实化和Ge-O-Ge键的形成。
The Ge-doped SiO2 films were fabricated by plasma-enhanced chemical vapor deposition,and annealed at different temperatures.The effects of thermal annealing on the properties of Ge-doped SiO2 films were investigated with prism coupler,atomic force microscope and Fourier transform infrared spectroscopy.It is found that for the Ge-doped SiO2 films annealed at 1 100 ℃,the change of both the positive refractive index and the negative volume increases with GeH4 flow,and the formation of Ge-O-Ge bond also increases,while for the films annealed at 900 ℃,the refractive index does not increase with GeH4 flow,and the surface roughness of the films decreases with the increase of annealing temperature.The results indicate that when too much Ge doping into SiO2 films will decrease the refractive index,but after annealed at 1 100 ℃,the refractive index of the films increases with GeH4 flow,and it is mainly due to the densification and formation of the Ge-O-Ge bond.