Wafer with a focus/exposure matrix
AssigneeVLSI Technology, Inc.
InventorPierre Leroux
Life of this patent
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Abstract
A focus/exposure matrix comprises a series of patterns disposed on a wafer. The patterns are arranged in rows and columns. The patterns in a row are characterized by having been formed with substantially the same exposure time and an effective focus that increments between successive row patterns by an amount substantially corresponding to half the focus resolution of the photostepper. The patterns in a column are characterized by having been formed with substantially the same effective focus and an exposure time that increments between successive column patterns by a finite amount.
Claims8
A wafer for use in optimizing the focus and exposure time of a photostepper, wherein the photostepper has a plurality of focus settings and a finite focus resolution, comprising:
- a focus/exposure matrix comprising a series of thin-film patterns disposed on said wafer, the patterns being arranged in rows and columns, the patterns in a row being characterized by having been formed with the same exposure time and an effective focus that increments between successive patterns by an amount half the focus resolution of the photostepper, the patterns in a column being characterized by having been formed with the same effective focus and an exposure time which increments between successive patterns.
Dependencies are inferred from the claim text.