M02000 - SEMI M20 - Practice for Establishing a Wafer Coordinate System Revision:SEMI M20-0215 - Superseded This Standard specifies measurement methods

This Standard specifies measurement methods

Because of the hazardous nature of chrome containing etchants

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and extinction

SEMI E133-1107 (technical revision)

M02000 - SEMI M20 - Practice for Establishing a Wafer Coordinate System Revision:SEMI M20-0215 - Superseded This Standard specifies measurement methodsNOTICE: This Document was reapproved with minor editorial changes. Processing systems now employed in advanced device manufacturing use aligning mechanisms to position the wafer rotationally and in x y prior to processing. Many of these scan the wafer periphery and determine the geometric center of the wafer surface. This is most often seen on stepping aligners, to minimize the effects of wafer to wafer diameter variation in mixed aligner type fabs.