Patent ID: 7181057
Filing Date: 2007-02-20
Classification: G03F,G06K,G06T,Y10S

Abstract:
1. An overlay mark for determining a relative position between two or more successive layers of a substrate or between two or more separately generated patterns on a single layer of a substrate, the overlay mark comprising: a plurality of working zones used to calculate alignment between a first and a second layer of the substrate or between a first and a second pattern on a single layer of the substrate, each of the working zones being positioned within the perimeter of the mark, each of the working zones representing a different area of the mark, the working zones being configured to substantially fill the perimeter of the mark such that the combined area of the working zones is substantially equal to the total area of the mark, wherein the overlay mark is divided into four equal quadrants, each quadrant including at least one working zone, a first set of quadrants being in a first opposed relationship, a second set of quadrants being oriented in a second opposed relationship that lies crosswise relative to the first set of quadrants, the first set of quadrants each including at least a first working zone, the first working zones being generated together in the first layer or first pattern, the second set of quadrants each including at least a second working zone, the second working zones being generated together in the second layer or second pattern.