Patent ID: 7599063
Filing Date: 2009-10-06
Classification: G03F

Abstract:
1. A method for checking alignment accuracy, which is applicable for checking the alignment accuracy in a photolithography process for defining an upper layer on a wafer with respect to a lower layer on the wafer, the method comprising: forming a plurality of overlay marks, comprising: performing a measurement process to obtain a first relation between only the interior profile of the each outer mark of the plurality of the outer marks and only the interior profile of another outer mark of the plurality of the outer marks and a second relation between the each correspondingly above inner mark of the plurality of the inner marks and another correspondingly above inner mark of the plurality of the inner marks or to obtain a third relation between only the interior profile of the each outer mark of the plurality of the outer marks and the each correspondingly above inner mark of the plurality of the inner marks; and calculating a X-directional alignment and a Y-directional alignment for the photolithography process with respect to the lower layer using the first and the second relations or the third relation.