Metrology of Wide Field of View Nano-Thickness Foils' Homogeneity by Conventional and Phase Contrast Soft X-ray Imaging

A tabletop ultra-bright, debris-free femtosecond-laser-driven cluster-based plasma soft X-ray source, which emits more than $10^{12}$ photons/(sr$\cdot$pulse) in the spectral range 1–10 nm within a $4\pi$ sr solid angle was developed. Using such source in combination with a high dynamic range LiF crystal soft X-ray detector allows obtaining contact and propagation-based phase-contrast images of nanostructures with 700 nm spatial resolutions in a wide field of view. It was demonstrated that the high precision of used techniques enable distinguishing inhomogeneity of measured intensities of ultrathin foils in the order of $\pm 3$%. All of this opens a new approach for PBPC imaging and metrology of full areas of free-standing or mesh-supported nano-thickness foils, or other nanostructures.