Patent ID: 6330355
Filing Date: 2001-12-11
Classification: G03F

Abstract:
An alignment monitor for overlay images, comprising:a transparent mask substrate;a first chip image, a first scribeline region containing a first alignment region, a second chip image, and a second scribeline region containing a second alignment region formed in a layer of opaque material on said transparent mask substrate;a first number of parallel and equally spaced transparent first horizontal alignment lines formed in said layer of opaque material in said first alignment region, wherein the space between adjacent said first horizontal alignment lines is a first distance and one of said first horizontal alignment lines is longer than the other said first horizontal alignment lines;a second number of parallel and equally spaced transparent first vertical alignment lines formed in said layer of opaque material in said first alignment region, wherein the space between adjacent said first vertical alignment lines is said first distance, one of said first vertical alignment lines is longer than the other said first vertical alignment lines, and said first vertical alignment lines are perpendicular to said first horizontal alignment lines;said first number of parallel and equally spaced transparent second horizontal alignment lines formed in said layer of opaque material in said second alignment region, wherein the space between adjacent said second horizontal alignment lines is a second distance, said second distance is a third distance less than said first distance, and one of said second horizontal alignment lines is longer than the other said second horizontal alignment lines; andsaid second number of parallel and equally spaced transparent second vertical alignment lines formed in said layer of opaque material in said second alignment region, wherein the space between adjacent said second vertical alignment lines is said second distance, one of said second vertical alignment lines is longer than the other said second vertical alignment lines, and said second vertical alignment lines are perpendicular to said second horizontal alignment lines.