X-ray reflectometry apparatus and method thereof for measuring three dimensional nanostructures on flat substrate

An X-ray reflectometry apparatus for measuring a three-dimensional nanostructure on a flat substrate, comprising:

• an X-ray source for emitting an X-ray of one wavelength in a multi-wavelength range of 0.154 nm-20 nm;
• an X-ray reflector comprising multiple mirrors or a X-ray monochromator;
• a six-axis platform configured to control a focus distance of the X-ray reflector such that the focus distance is ≥150 mm, so that the X-ray is point focused on a sample surface from an incident angle ≥24° and a footprint of the focused X-ray is less than or equal to 10 μm×25 μm;
• an incident slit disposed between the X-ray reflector and the sample surface, wherein the focused X-ray is controlled by the incident slit to change a divergence angle, and the incident slit is an aperture optical element or a slit element that is controlled in at least one direction;
• an X-ray detector configured to collect reflecting and scattering signals from the sample surface, which includes a 2-dimensional X-ray sensor inside a vacuum chamber and an analyzer outside the vacuum chamber;
• and
• a controller configured to control the 2-dimensional X-ray sensor to move along a z-axis with the incident angle of the focused X-ray for collecting the scattering and reflecting signals.