ZrO_2/SiO_2多层膜中膜厚组合周期数及基底材料对残余应力的影响

Influences of the period of repeating thickness on the stress of alternative high and low refractivity ZrO_2/SiO_2 multilayers

ZrO2/SiO2多层膜由相同沉积条件下的电子束蒸发方法制备而成,通过改变多层膜中高(ZrO2)、低(SiO2)折射率材料膜厚组合周期数的方法,研究了沉积在熔石英和BK7玻璃基底上多层膜中残余应力的变化.用ZYGO光学干涉仪测量了基底镀膜前后曲率半径的变化,并确定了薄膜中的残余应力.结果发现,该多层膜中的残余应力为压应力,随着薄膜中膜厚组合周期数的增加,压应力值逐渐减小.而且在相同条件下,石英基底上所沉积多层膜中的压应力值要小于BK7玻璃基底上所沉积多层膜中的压应力值.用x射线衍射技术测量分析了膜厚组合周期数不同的ZrO2/SiO2多层膜微结构,发现随着周期数增加,多层膜的结晶程度增强.同时多层膜的微结构应变表现出了与所测应力不一致的变化趋势,这主要是由多层膜中,膜层界面之间复杂的相互作用引起的.

The effect of period of repeating thickness on the stress is studied in ZrO2/SiO2 multilayers deposited by electron beam evaporation on BK7 glass and fused silica substrates, separately. The results show that the residual stress in the multilayers is compressive, and with the increase of the period of repeating thickness the residual stress in multilayers decrease in both BK7 and fused silica substrates. At the same time, the residual stress in multilayers deposited on BK7 glass substrates is less than that in the samples deposited on fused silica substrates. The variation of the microstructure examined by the x-ray diffraction shows that the microscopic deformation does not correspond to the macroscopic stress, which may be due to the variation of the interface stress.