Patent ID: 9239283
Filing Date: 2016-01-19
CPC Classification: G01N

Claim Text:
1. A defect inspection device, comprising: a stage unit which is movable at least in one direction with a test specimen placed thereon; a light irradiation unit which irradiates the test specimen placed on the stage unit with linearly shaped light from a direction inclined relative to a normal direction of a surface of the stage on which the test specimen is placed; a first light collecting/detecting unit which collects and detects light reflected/scattered in a first direction from the test specimen irradiated with the linearly shaped light by the light irradiation unit; a second light collecting/detecting unit which collects and detects light reflected/scattered in a second direction from the test specimen irradiated with the linearly shaped light by the light irradiation unit; a processing unit which processes a detection signal output from the first light collecting/detecting unit and a detection signal output from the second light collecting/detecting unit to detect a defect on the test specimen; and a control unit which controls the stage unit, the light irradiation unit, the first light collecting/detecting unit, the second light collecting/detecting unit and the processing unit, wherein each of the first light collecting/detecting unit and the second light collecting/detecting unit has a photoelectric converter provided with a plurality of optical sensor arrays, and the processing unit obtains misalignment of a focal position of the first light collecting/detecting unit relative to a surface of the test specimen by using detection signals from the plurality of optical sensor arrays of the first light collecting/detecting unit, obtains misalignment of a focal position of the second light collecting/detecting unit relative to the surface of the test specimen by using detection signals from the plurality of optical sensor arrays of the second light collecting/detecting unit, corrects the detection signal output from the first light collecting/detecting unit and the detection signal output from the second light collecting/detecting unit in accordance with the obtained misalignment of the focal position of the first light collecting/detecting unit and the obtained misalignment of the focal position of the second light collecting/detecting unit, combines together the detection signal output from the first light collecting/detecting unit and the detection signal output from the second light collecting/detecting unit which have been corrected to detect the defect on the test specimen.