Segmented bar-in-bar target

摘要

A target for measurement of critical dimension bias on a substrate formed by a lithographic process comprises three sets of contrasting arrays of elements on the substrate. Each of the arrays has a plurality of spaced parallel elements contrasting with the substrate. Ends of the contrasting elements are aligned along parallel lines forming opposite array edges, with the length of the contrasting elements comprising the array width. The array edges are measurable by microscopy without resolution of individual elements of the array. The three arrays are spaced apart in the X- or Y-direction such that critical dimension bias may be measured by comparing the centerline of a first distance measured from one edge of the first array to one edge of the third array to the centerline of a second distance measured from one edge of the second array to one edge of the third array, with the centerlines being measured without resolution of the individual array elements.