大尺寸中阶梯光栅具有大孔径和极高的衍射级次, 可以实现普通光栅难以达到的极高光谱分辨率。中阶梯光栅通常是利用刻划机在厚铝膜上刻划而成, 所以制备大面积均匀性的高质量铝膜刻划基底是实现高性能大尺寸中阶梯光栅的关键因素。在较厚铝膜的制备工艺中, 基底温度是至关重要的工艺参数。本文通过电子束热蒸发镀铝工艺在不同基底温度下制备了厚铝膜样品, 并利用原子力显微镜、扫描电镜等手段从宏观和微观尺度详细分析了基底温度对铝膜质量的影响。铝膜平均晶粒尺寸从100 ℃时的26434 nm增大到200 ℃时的38497 nm和300 ℃时的59635 nm, 表面粗糙度Rq从100 ℃时的347 nm增长到200 ℃时的589 nm和300 ℃时的951 nm。结果表明, 随着基底温度的升高表面粗糙度迅速增大, 铝膜的表面质量严重退化。

Large-size echelle grating has extremely high spectral resolution due to its large aperture and high diffractive order. Generally, echelle grating ruling is performed on a thick Al film. Consequently, the preparation of high-quality large-area thick Al films becomes one of the most important factors to realize a high-performance large-size echelle grating. In the thick Al films deposition process, substrate temperature is the most important technological parameter. In this paper, the thick Al films samples are prepared at different temperatures by electron-beam evaporation technique. Then, the influence of substrate temperature on the Al films quality are analyzed by means of an atomic force microscope and scanning electron microscope. It is found that the average grain size and surface roughness increase rapidly from 26434 nm, 347 nm at 100 ℃ to 38497 nm, 589 nm at 200 ℃ and 59635 nm, 951 nm at 300 ℃. Experimental results show that with an increased substrate temperature, grain size and surface roughness increase sharply and the surface quality of thick Al films degrades seriously.