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Hitachi Ltd
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Hitachi Ltd
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Application filed by Hitachi LtdfiledCriticalHitachi Ltd
Priority to JP7318276ApriorityCriticalpatent/JPS52156571A/en
Publication of JPS52156571ApublicationCriticalpatent/JPS52156571A/en
PURPOSE: To reduce mask alignment time by simultaneously performing the optical and electrical detection of the lapped image of a mask and a wafer in 45° direction to the right and left.