An X-ray diffraction system uses a two-dimensional detector to detect diffracted X-ray energy at a plurality of radial positions surrounding a sample location, the results at each position being combined to form a final diffraction image. To minimize smearing in the final image, the detector pixel intensities at each position are reapportioned among the pixel locations prior to being combined with the intensities collected at other positions. A two-dimensional pixel array space of the detector is projected onto a cylinder to form a projected pixel array space, and a virtual cylindrical detection surface representative of an ideal cylindrical detector is determined. An overlap between the pixels of the projected pixel array space and the pixels of the virtual cylindrical detection surface is determined, and pixel intensities are reapportioned accordingly. The reapportionment may include dividing each pixel space into subpixels and redistributing the subpixels among adjacent pixels.

A method for X-ray scatterometry includes receiving a first distribution of an X-ray beam scattered from a sample. The first distribution exhibits asymmetry with respect to a reference axis. A correction is applied to the first distribution, so as to produce a second distribution in which a level of the asymmetry is reduced relative to the first distribution. One or more parameters of the sample are estimated based on the second distribution.

An X-ray diffraction system uses a two-dimensional detector to detect diffracted X-ray energy at a plurality of radial positions surrounding a sample location, the results at each position being combined to form a final diffraction image. To minimize smearing in the final image, the detector pixel intensities at each position are reapportioned among the pixel locations prior to being combined with the intensities collected at other positions. A two-dimensional pixel array space of the detector is projected onto a cylinder to form a projected pixel array space, and a virtual cylindrical detection surface representative of an ideal cylindrical detector is determined. An overlap between the pixels of the projected pixel array space and the pixels of the virtual cylindrical detection surface is determined, and pixel intensities are reapportioned accordingly. The reapportionment may include dividing each pixel space into subpixels and redistributing the subpixels among adjacent pixels.

A method includes receiving, by a processing device, a first small angle scattering image of a substrate. The substrate includes a number of structures oriented at a first angle relative to a base of the substrate. The first small angle scattering image of the substrate is collected at a second angle of incidence of radiation relative to the base of the substrate, different than the first angle. The method further includes determining a first-order Fourier term associated with the first small angle scattering image by performing angular Fourier decomposition of the first small angle scattering image. The method further includes determining a value of the first angle based on the first-order Fourier term.