Recent Advancements in Small Angle X-ray Scattering: Synchrotron Grazing Incidence X-ray Scattering, Specular X-ray Reflectivity and Their Combinations

Pohang Accelerator Laboratory, Pohang University of Science & Technology
â—‹Moonhor Ree Jinhwan Yoon Kyuyoung Heo Kyeong Sik Jin Sangwoo Jin Byeongdu Lee Jehan Kim Kwang-Woo Kim

Conventional small angle X-ray and neutron scattering (SAXS and SANS) have been widely used to determine the large scale features of nanostructures, particularly in bulk specimens. However, these conventional scattering techniques are not applicable to nanostructures supported with substrates or in supported thin films because of their low sensitivity and resolution, which arise for low scattering volumes and when the substrates are much thicker than the nanostructures. Thus, a nondestructive method is required for the quantitative analysis of nanostructures supported with substrates or in supported thin films. In this paper, we describe a nondestructive grazing incidence small angle X-ray scattering (GISAXS) technique, which can produce a high intensity scattering pattern with high statistical significance even for thin films with a thickness of tens of nanometers that are supported with substrates. However, the use of the GISAXS technique is only possible in conjunction with scattering theory development and intensive data analysis because grazing incidence scattering is complicated by reflection and refraction effects that are not found in conventional small angle scattering. Due to these complexities of GISAXS data analysis, the full use of the power of GIXS in the characterization of nanostructure systems has been limited. The GISAXS theory is introduced and its power is demonstrated with quantitative data analyses of various nanostructure systems (for example, nanostructures with and without patterning, and single- and multi-layer nanostructures). Further, the GISAXS technique becomes more powerful when it is used together with specular X-ray reflectivity method.