Patent ID: 8055058

Claim:
An apparatus for detecting defects in a wafer, comprising: an inspection stage having an inspection region, on which a wafer to be inspected is disposed, formed of a transmissive material; an optical part disposed under the inspection stage and radiating infrared light onto the wafer to be inspected; an image obtaining part formed of a plurality of line sensors having a striped photographing region respectively, and detecting the infrared light transmitted through the wafer disposed on the inspection stage to output an image signal; a conveying part for conveying the image obtaining part or the inspection stage in a short-side direction of the photographing region of the line sensor, and outputting a pulse signal having a predetermined period corresponding to a relative straight moving distance between the image obtaining part and the inspection stage; a controller for counting the pulse signal and controlling the image obtaining part to photograph the wafer whenever the wafer is conveyed in the short-side direction of the photographing region of the line sensor toward the image obtaining part by a distance corresponding to the length of short sides of the photographing region; and a defect detection part for combining each image signal output from the image obtaining part to generate an inspection image corresponding to the wafer, and detecting positions of defects existing in the wafer from the inspection image, wherein each of the line sensors transmits charges accumulated therein to a line sensor adjacent in an opposite direction of the conveyance direction when a photographing instruction signal is input from the controller, and then detects the infrared light transmitted through the wafer disposed on the inspection stage, and the line sensor positioned at an end in an opposite direction of the conveyance direction outputs charges accumulated therein as the image signal from a time when the number of input photographing signals exceeds the number of line sensors.