摘要
红外滤光片,尤其是中长波红外窄带滤光片等光谱指标要求较高的红外光学薄膜,膜层厚度能达到几十微米,因而对膜料的需求非常大。当镀膜真空室较大时,一次填料不能满足膜料用量需求,通常采用减小蒸发距离的方式提高膜料的利用率,但同时会使膜厚均匀性变差,光谱性能变差。通过镀膜理论分析,在满足产品镀膜均匀性的前提下,设计了一套可自由调节高度及大小的旋转平面基片工装,以减小蒸发源与镀膜基片的距离,提高膜料利用率。理论计算表明,当工件盘和蒸发源之间的垂直高度与蒸发源和工件盘转轴的距离之比为1.8、蒸发源是小平面源时,膜厚不均匀性不大于0.20%。采用该装置制备中波红外短波通滤光片,置于工件盘中心与边缘位置的滤光片半功率点位置相差8 nm,与理论计算的膜厚不均匀性(0.18%)对应一致。
In general,infrared filters have thicker films,especially infrared optical films with high spectral requirements such as medium and long-wave infrared narrowband filters.The film thickness can reach tens of microns and the demand for film materials is very large.The uniformity has a very obvious influence on the spectral performance.If the coa ting vacuum chamber is large,the primary material will often not meet the requirement of the film material consumption,which is usually solved by reducing the evaporation distance,but this will bring about problems such as poor film thickness uniformity.According to the analysis of the coating theory,under the condition of satisfying the film uniformity,a set of rotating flat substrate support plate with freely adjustable height and size is designed to reduce the distance between the evaporation source and substrate.When the ratio of the vertical height between the work plate and the evaporation source to the distance between the evaporation source and the rotating shaft of the work plate is 1.8,the unevenness of the film thickness is 0.20%for a small area source.The prepared mid-wave infrared short-wave pass filter has a maximum spectral difference of 8 nm between the center point and the edge position of the work plate,which is consistent with the uniformity of the film thickness obtained by theoretical calculations.
作者
徐嶺茂
王济洲
李坤
王多书
周晖
XU Lingmao;WANG Jizhou;LI Kun;WANG Duoshu;ZHOU Hui(Science and Technology on Vacuum Technology and Physics Laboratory,Lanzhou Institute of Physics,Lanzhou 730000,China)
出处
《真空与低温》
2021年第5期444-448,共5页
Vacuum and Cryogenics
基金
真空技术与物理重点实验室重点基金(ZD171902)。
关键词
膜厚均匀性
基片工装
蒸镀工艺
红外滤光片
thickness uniformity
substrate holder
theoretical analysis
evaporation
