Pattern forming system

Claim 1

A pattern forming system comprising: a reticule on which a pattern is formed of one or more chips; arranging means for preliminarily arranging a plurality of shot regions on a main surface of a wafer in a matrix arrangement where each shot region is formed by one shot of the pattern formed on the reticule, the matrix arrangement including a basic shot region positioned proximate the center of the matrix arrangement wherein the basic shot region has a central point; calculating means for calculating the number of the shot regions which constitute said matrix arrangement by sequentially moving the matrix arrangement on the main surface of the wafer to move the central point of the basic shot region in a two-dimensional coordinate system comprised of an X axis and an Y axis having an origin defined at a center of the wafer, wherein each sequential movement of the matrix arrangement moves the central point of the basic shot region in a range of -S.sub.x /2≦x≦S.sub.x /2, and -S.sub.y /2≦y≦S.sub.y /2, where S x is a size of each shot region in a direction along the X axis, and S y is a size of each shot region in a direction along the Y axis, said calculating means further calculating the number of the chips to be completely formed on said main surface of said wafer by each sequential movement of the matrix arrangement; selecting means for selecting a case in which the number of shot regions constituting said matrix arrangement is smallest and the number of chips to be completely formed on said main surface of said wafer is largest; and forming means for forming said pattern, which is formed on said reticule, on the main surface of the wafer for each shot region of the matrix arrangement.