A method for X-ray measurement includes generating and directing an X-ray beam to a sample including at least first and second layers stacked on one another, the X-ray beam incident on a sample location at which the first and second layers include respective first and second high aspect ratio (HAR) structures. X-ray scatter profiles are measured, that are emitted from the sample location in response to the X-ray beam as a function of tilt angle between the sample and the X-ray beam. A shift is estimated, between the first and second layers and a characteristic tilt of the first and second layers, based on the X-ray scatter profiles measured as a function of the tilt angle.