Patent ID: 8891061
Filing Date: 2014-11-18
Classification: G03F

Abstract:
1. A method comprising: printing a marker on a substrate using an exposure apparatus and a mask, the mask including a pattern for creating the marker, the pattern comprising an array of structures wherein each structure of the array of structures comprises an array of substructures, the array of structures having a variable pitch in one direction that is resolvable by the exposure apparatus and the array of substructures of each structure of the array of structures having a pitch between 0 and 70 nm in a second direction different from the first direction; and measuring a property of the substrate that has been exposed by the exposure apparatus and the mask, the measuring comprising: projecting a radiation beam onto the marker on the substrate; detecting radiation reflected from the marker on the substrate; and determining, from the properties of the reflected radiation, at least one of focus and dose related properties of the exposure apparatus.