A system to generate multiple beam lines in an oblique angle multi-beam spot scanning wafer inspection system includes a beam scanning device configured to scan a beam of illumination, an objective lens oriented at an oblique angle relative to the surface of a sample and with an optical axis perpendicular to a first scanning direction on the sample, and one or more optical elements positioned between the objective lens and the beam scanning device. The one or more optical elements split the beam into two or more offset beams such that the two or more offset beams are separated in a least a second direction perpendicular to the first direction. The one or more optical elements further modify the phase characteristics of the two or more offset beams such that the two or more offset beams are simultaneously in focus on the sample during a scan.