Patent ID: 8064730

Claim:
A device manufacturing method comprising: patterning a beam of radiation using a patterning device; determining a rotational position orientation of a substrate by: acquiring an image of each of at least two structures disposed on said substrate; determining a distance vector in a measurement coordinate system between the at least two structures disposed on said substrate by comparing the respective images of the at least two structures, said at least two structures having corresponding features and of which relative positions are known in relation to a pattern coordinate system different from the measurement coordinate system; decomposing the distance vector into a first distance along a first axis of the measurement coordinate system and a second distance along a second axis of the measurement coordinate system; and calculating a rotational position of the pattern coordinate system in relation to the measurement coordinate system using the first and the second distance; and aligning the substrate and the patterning device according to the rotational position orientation of the substrate; and projecting the patterned beam of radiation onto a target portion of a layer of radiation-sensitive material disposed on the substrate.