Abstract: A method of processing a substrate includes providing a substrate with a line pattern including lines extending in a longitudinal direction and exposing the line pattern to a directional beam. The directional beam has an azimuthal component substantially parallel to the longitudinal direction. Exposing the line pattern to the directional beam may concurrently deposit material on sidewall surfaces of the line pattern and etch surfaces of the line pattern with a normal component parallel to the longitudinal direction. The line pattern may have localized defects. The deposited material may mitigate pinch defects in the line pattern. The etched surfaces may mitigate bridge defects in the line pattern. A controller may be configured to cause the substrate to be processed according to the method. The controller may be included in a system further including a beam source and a substrate positioner.