Patent ID: 8436633

Claim:
A method to determine a quality of a needle mark including, when an electrical property test is performed on a plurality of devices formed on a semiconductor wafer by electrically contacting a plurality of electrode pads of each of the plurality of devices with a plurality of probes, obtaining a captured image of the semiconductor wafer by an image capturing means, and determining if respective marks formed on the plurality of electrode pads of the devices are good or bad as probe needle marks based on the captured image, the method comprising: selecting an object device including an object electrode pad with an indefinite mark as a probe needle mark formed thereon, and selecting a certain number of comparison devices preceding the object device at successive times and another certain number of comparison devices following the object device at successive times along a test direction, and determining if the indefinite mark of the object electrode pad is good or bad as the probe needle mark based on a change in marks over time among the indefinite mark of the object electrode pad and marks formed on respective comparison electrode pads of the plurality of comparison devices preceding and following the object device, the respective comparison electrode pads corresponding to the object electrode pad.