Samsung patents dark field system for spotting tiny defects on chips

1. A dark field defect inspection system comprising: a stage on which an inspection substrate is arranged; an illumination optical system configured to radiate incident light to a top surface of the inspection substrate and arranged along a first oblique optical axis rotated in a first rotation direction from a normal line to the top surface of the inspection substrate by an oblique angle; a calibration optical system configured to receive calibration light and arranged along a second oblique optical axis rotated in a second rotation direction from the normal line by the oblique angle, the second rotation direction being opposite to the first rotation direction; and an inspection optical system configured to receive inspection light and arranged along a vertical optical axis extending upward from the inspection substrate, wherein the illumination optical system includes: a light source configured to output the incident light; a delivery optical system configured to shape the incident light output from the light source into a preset shape, the delivery optical system including at least one lens; a first phase retardation plate and a second phase retardation plate each configured to delay a phase of the incident light; and a linear polarizer arranged between the first phase retardation plate and the second phase retardation plate, the inspection optical system includes: an inspection detector configured to receive the inspection light; an objective lens facing an inspection region of the inspection substrate; a tube lens arranged before the inspection detector along the vertical optical axis; an inspection analyzer arranged after the objective lens along the vertical optical axis; and an aperture arranged along the vertical optical axis and arranged in an exit pupil plane of the objective lens, the delivery optical system of the illumination optical system includes a cylindrical lens arranged between the first phase retardation plate and the light source along the first oblique optical axis, the exit pupil plane of the objective lens includes a virtual plane on which the inspection light exiting the objective lens converges, the oblique angle is about 50 degrees to about 75 degrees, and the calibration light and the inspection light include scattered light from the inspection substrate.