Lodha G S, Yamashita K, Kunieda H, Tawara Y, Yu J, Namba Y, Bennett J M
Appl Opt. 1998 Aug 1;37(22):5239-52. doi: 10.1364/ao.37.005239.
Grazing-incidence specular reflectance and near-specular scattering were measured at Al-K(alpha) (1.486-keV, 8.34-?) radiation on uncoated dielectric substrates whose surface topography had been measured with a scanning probe microscope and a mechanical profiler. Grazing-incidence specular reflectance was also measured on selected substrates at the Cu-K(alpha) (8.047-keV, 1.54-?) wavelength. Substrates included superpolished and conventionally polished fused silica; SiO(2) wafers; superpolished and precision-ground Zerodur; conventionally polished, float-polished, and precision-ground BK-7 glass; and superpolished and precision-ground silicon carbide. Roughnesses derived from x-ray specular reflectance and scattering measurements were in good agreement with topographic roughness values measured with a scanning probe microscope (atomic force microscope) and a mechanical profiler that included similar ranges of surface spatial wavelengths. The specular reflectance was also found to be sensitive to the density of polished surface layers and subsurface damage down to the penetration depth of the x rays. Density gradients and subsurface damage were found in the superpolished fused-silica and precision-ground Zerodur samples. These results suggest that one can nondestructively evaluate subsurface damage in transparent materials using grazing-incidence x-ray specular reflectance in the 1.5-8-keV range.
在 Al - K(α)（1.486 keV，8.34 Å）辐射下，对表面形貌已用扫描探针显微镜和机械轮廓仪测量过的未镀膜介电基板进行掠入射镜面反射和近镜面散射测量。还在 Cu - K(α)（8.047 keV，1.54 Å）波长下对选定基板进行掠入射镜面反射测量。基板包括超抛光和传统抛光的熔融石英；SiO₂ 晶圆；超抛光和精密研磨的微晶玻璃；传统抛光、浮法抛光和精密研磨的 BK - 7 玻璃；以及超抛光和精密研磨的碳化硅。通过 X 射线镜面反射和散射测量得出的粗糙度与用扫描探针显微镜（原子力显微镜）和机械轮廓仪测量的形貌粗糙度值高度吻合，这些测量涵盖了相似范围的表面空间波长。还发现镜面反射对抛光表面层的密度以及直至 X 射线穿透深度的亚表面损伤敏感。在超抛光熔融石英和精密研磨的微晶玻璃样品中发现了密度梯度和亚表面损伤。这些结果表明，利用 1.5 - 8 keV 范围内的掠入射 X 射线镜面反射可以无损评估透明材料中的亚表面损伤。
