Dark field defect inspection system and inspection method thereof

A dark field defect inspection system comprising:

• a stage;
• an illumination optical system configured to radiate incident light to a top surface of an inspection substrate 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 traveling 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 traveling 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 half-wave plate arranged after the light source along the first oblique optical axis;
• a linear polarizer arranged after the half-wave plate along the first oblique optical axis;
• and
• a quarter-wave plate arranged after the linear polarizer along the first oblique optical axis, 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 along the vertical optical axis and arranged in a first exit pupil plane of the objective lens;
• and
• an aperture arranged along the vertical optical axis and arranged in a second exit pupil plane of the objective lens, and
• the first exit pupil plane and the second exit pupil plane each include a virtual plane on which the inspection light exiting the objective lens converges.

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 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 traveling 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 traveling along a vertical optical axis from the inspection substrate,
• wherein the illumination optical system includes:
• a light source configured to output the incident light;
• a first phase retardation plate and a second phase retardation plate each arranged along the first oblique optical axis and 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 along the first oblique optical axis,
• the inspection optical system includes:
• an inspection detector configured to receive the inspection light;
• an objective lens arranged along the vertical optical axis and facing an inspection region of the inspection substrate;
• a tube lens arranged before the inspection detector along the vertical optical axis;
• a first relay lens and a second relay lens arranged between the objective lens and the tube lens along the vertical optical axis;
• an inspection analyzer arranged between the first relay lens and the second relay lens along the vertical optical axis;
• and
• an aperture arranged before the tube lens along the vertical optical axis,
• the inspection analyzer is arranged in a rear focal plane of the first relay lens and a front focal plane of the second relay lens,
• the aperture is arranged in a rear focal plane of the second relay lens and a front focal plane of the tube lens,
• 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.