基底温度对电子束沉积SiO2薄膜的影响

Influence of Substrate Temperature on SiO_2 Thin Films by Electron Beam Deposition

利用热力学统计理论及薄膜生长理论,给出了薄膜堆积密度、折射率与基底温度之间的关系。在实验中采用电子束热蒸发技术,在不同的沉积速率和基底温度下制备了单层二氧化硅薄膜。研究了沉积速率与薄膜表面均匀度及折射率的关系,并着重分析了基底温度对薄膜折射率、透射率、表面形貌及微观结构的影响。实验结果表明:基底温度升高,薄膜表面粗糙度减小,晶粒间隙缩小,折射率增加,透射率提高,吸收度降低。且当基底温度为500℃时,在可见光区域SiO2薄膜的透射率可达99.4%以上。对实验数据进行拟合,理论计算与实验结果符合得很好。

The relationship of stacking density,refractive index and substrate temperature is obtained by statistical thermodynamics theory and thin film growth mechanism.Monolayer SiO2 thin films are fabricated at different substrate temperatures and deposition rates by electron beam evaporation technology.The relationships between deposition rate and surface uniformity,the refractive index are studied.The influence of substrate temperature on the refractive index,transmittance,morphology,microstructure of thin films is emphatically analyzed.It shows that the surface roughness decreases,the crystalline grain gap narrows,the refractive index and transmittance increase,absorption degree reduces with the increasing of substrate temperature.When the substrate temperature is 500℃,the transmittance of SiO2 thin films in the visible light is above 99.4%.Through fitting experimental data,theory calculation agrees well with the experimental results.