Patent ID: 8339593
Filing Date: 2012-12-25
Classification: G01N

Abstract:
1. A laser scattering defect inspection system that irradiates a laser beam on a surface of a workpiece to detect the light beam scattered from the surface, thereby detecting presence of defects, the laser scattering defect inspection system comprising: a stage mover that rotates the workpiece and transports the workpiece in one direction; a laser light source that emits the laser beam that has a beam diameter toward the workpiece mounted on the stage mover; an optical deflector that cross scans the laser beam emitted from the laser light source on the workpiece, where a scan width of a cross scan is a quantity of laser beam movement caused by the optical deflector; an optical detector that detects the laser beam scattered from the surface of the workpiece; a storage that stores defect inspection conditions for each of a plurality of inspections of the workpiece in a manufacturing process, where the conditions include a rotation speed and a moving speed of the workpiece by the stage mover, a scan width on the workpiece and a scan frequency by the optical deflector; and a controller that reads the defect inspection conditions stored for each of a plurality of inspections of the workpiece in the storage and controls the driving of the stage mover and the optical deflector under the conditions, wherein the controller controls the stage mover, the laser light source, the optical deflector and the optical detector, and the controller performs a first inspection step of defect inspection as a preliminary inspection for performing actual condition investigation, which classifies the defects, and a second inspection step of defect inspection that only counts a quantity of the defects but does not perform actual condition investigation, which classifies the defects, the optical deflector stops the cross scan when the controller performs the first inspection step, while the stage mover rotates and transports the workpiece and the optical detector detects the laser beam scattered from the surface of the workpiece, and the scan width of the cross scan is controlled to be equal or larger than the beam diameter on the workpiece in the second inspection step, while the stage mover rotates and transports the workpiece and the optical detector detects the laser beam scattered from the surface of the workpiece.