Patent ID: 7176433
Filing Date: 2007-02-13
Classification: G01N,H01L

Abstract:
1. A line-scan wafer inspection system having the capability of forming an image of an illuminated wafer sample, said wafer inspection system including: a line imaging system and associated optics; said imaging system including a scanner sensor array for optically sampling outgoing light from said sample surface, said scanner sensor array comprising a plurality of coplanar linear sensor arrays in a focal plane, each said linear sensor array arranged perpendicular to a scan direction of said scanner sensor array relative to said sample, each said linear sensor array comprising abutting optical sensors, each said sensor being a pixel having a pixel width, each said linear sensor array having an actual linear pixel density, wherein; said scanner sensor array is arranged to provide a shift in sampling in adjacent linear sensor arrays, wherein the sampling in at least a portion of said linear sensor arrays is shifted by a fraction of a pixel width with respect to adjacent linear sensor arrays, to provide optical sampling data from said sample which yields an effective linear pixel density greater than said actual linear pixel density; wherein said shift in sampling in adjacent linear sensor arrays is provided by one selected from the group consisting of: a) said scanner sensor array being rotated in said focal plane by an angle θ with respect to said scan direction; and b) a first portion of each pixel being masked and a second portion of each pixel being unmasked, wherein said second portion is shifted in each successive linear sensor array, such that the sampling is performed at progressively offset locations.