Darkfield inspection system having a programmable light selection array

An surface inspection apparatus comprising:

• an illumination source for directing a light beam onto a workpiece;
• a programmable light selection array positioned to receive light scattered from the workpiece, the programmable light selection array for directing said light onto to a photodetector element and also capable of selectively directing selected portions of the light onto to a photosensor element;
• the photodetector element being positioned such that it receives light from the programmable light selection array and translates said received light into an associated electrical signal;
• processing circuitry for receiving and analyzing the associated electrical signal from the first photodetector element and thereby determining an ordinary scattering portion of the of the light scattered from the workpiece that is associated with an ordinary scattering pattern of the workpiece and determining a defect portion of the light scattered from the workpiece that is associated with defects of the workpiece;
• control circuitry for activating and deactivating light selection elements of the programmable light selection array so that said selected portions of the light comprising the defect portion of the light scattered from the workpiece are selectively directed onto the photosensor element that translates said defect portion into a defect electrical signal;
• defect analysis circuitry for receiving and analyzing the defect electrical signal from the photosensor element to characterize defects the workpiece.