Patent ID: 8319149

Claim:
A method of processing a workpiece having a workpiece surface to be treated, comprising: generating a beam of radiation and projecting said beam onto said workpiece surface as a two-dimensional rectangular line beam having a long dimension L along a first axis and a short dimension along a second axis; repetitively performing the following with respect to first and second halves of said workpiece surface, said first and second halves being separated by an imaginary boundary line parallel to said second axis: (a) scanning said beam in a first direction parallel to said second axis in a row located in said first half of said workpiece surface; (b) first translating said beam in a direction parallel to said first axis and toward said second half of said workpiece surface by a distance of approximately n·S, wherein S is a stepping distance which is a center-to-center spacing between successive rows and n is an integer such that n·S equals about half of a diameter of said workpiece; (c) scanning said beam in a second direction parallel to said second axis and opposite said first direction in a row located in said second half of said workpiece surface; (d) second translating said beam in a direction parallel to said first axis and toward said first half of said workpiece surface by a distance of approximately (n−1)·S; wherein S and L are related by an overlap (OVLP) of adjacent rows as follows: S =(1− OVLP ) L; and wherein scanning of said beam in said first half of said workpiece surface is performed in said first direction only and scanning of said beam in said second half of said workpiece surface is performed in said second direction only.