Patent ID: 9128388
Filing Date: 2015-09-08
Classification: G03F,H01L

Abstract:
1. A method of focus measurement comprising: projecting first and second line-and-space patterns on a substrate on which a photosensitive material is applied by irradiating first exposure light from a first direction that is displaced from an optical axis of an optical system on the first line-and-space pattern having a first pattern pitch and the second line-and-space pattern having a second pattern pitch; projecting third and fourth line-and-space patterns on the substrate by irradiating second exposure light from a second direction that is displaced from the optical axis of the optical system on the third line-and-space pattern having the first pattern pitch and the fourth line-and-space pattern having the second pattern pitch; calculating a sum of a dislocated amount on the substrate caused by a dislocation of focus and an overlap dislocation amount on the substrate between the first and third line-and-space patterns as a first dislocation amount by measuring a distance between the first line-and-space pattern and the third line-and-space pattern on the substrate; calculating an overlap dislocation amount on the substrate between the second and fourth line-and-space patterns as a second dislocation amount by measuring a distance between the second line-and-space pattern and the fourth line-and-space pattern on the substrate; and calculating the focus dislocation amount based on the first and second dislocation amounts.