沉积参量及时效时间对 SiO2薄膜残余应力的影响

SiO2 薄膜由电子束蒸发方法沉积而成。用GPI数字波面光学干涉仪测量了不同沉积条件下玻璃基底镀膜前后曲率半径的变化,并确定了 SiO2 薄膜中的残余应力。在其他条件相同的情况下,当沉积温度由 190 ℃升高到350 ℃时,SiO2 薄膜中的压应力由-156 MPa增大为-289 MPa。氧分压由3.0×10-3 Pa升高到13.0×10-3 Pa时,SiO2 薄膜中的应力由-223.5 MPa变为20.4 MPa。通过对薄膜折射率的测量,发现薄膜的堆积密度随沉积条件的改变也发生了规律性的变化。应力的变化主要是由于沉积时蒸发粒子的动能不同,导致薄膜结构不同引起的。同时,在样品的存放过程中,发现随着存放时间的延长,薄膜中的应力表现出了由压应力状态向张应力状态演变的趋势。

Influences of the Deposition Parameters and Aging Time on the Residual Stress of SiO2 Films

The residual stress in the SiO2 films deposited by electron beam evaporation under different conditions is measured by viewing the substrate deflection using GPI optical interferometer in different under cordition. The influences of deposition temperatures, oxygen partial pressure and aging on the The residual stress varies from -223.5 MPa to 20.4 MPa when the oxygen partial pressure increased from 3.0×10-3 Pa to 13.0×10-3 Pa, and from -150 MPa to -289 MPa when temperature increased from 190 ℃ to 350 ℃ which may be attributed to the variation of the microstructure concluding from the variation of the refractive index. An evolution of residual stress from compressive to tensile with time of sample storage in a conventional clean-room environment is measured for all evaporated SiO2 films investigated.