PURPOSE: To simplify the detection of a defect by comparing electric signals obtained with respect to the light transmission small windows of an inspecting mask and patterns at corresponding portions with those before completing electric signals of the entire pattern to judge a defect at the portion when the electric signals are not coincident.
CONSTITUTION: Signals are produced from CCDs 46, 48 in the state that an inspecting mark 20 is so positioned that X-ray transmission window is disposed at a position of registered E address. To this end, a timing controller 70 is connected with CCDs 46, 48, the timing of producing serial signals of X-ray images of the two CCDs 46, 48 are controlled to simultaneously obtain inspection signals from the CCDs 46, 48. The X-ray image signal obtained from the CCDs 46, 48 are converted to digital X-ray image data, compared by a digital computer 76, and a defect detection signal is output from the computer 76 when both data are discordant more than set level.
IIDA TAKAHIDE
MIYAKE HIROSHI
HATTORI SHUZO
HATTORI SHUZO
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