Patent ID: 8300212
Filing Date: 2012-10-30
Classification: G03F

Abstract:
1. A device manufacturing method of projecting a mask pattern of an alternating phase shift mask onto a substrate, the method comprising: illuminating the mask pattern with a beam of radiation to provide a zeroth order diffracted radiation, first first-order diffracted radiation and second first-order diffracted radiation emanating from the mask pattern; imaging the mask pattern onto a substrate using a projection system; and adjusting phase using an optical phase adjuster, wherein the zeroth and first-order diffracted radiation traverses the optical phase adjuster, the adjusting including: adjusting a phase of the zeroth order diffracted radiation to substantially match a phase of the first first-order diffracted radiation, or vice versa, using the phase adjuster, and adjusting a phase of the second first-order diffracted radiation to substantially match the phase of the first first-order diffracted radiation plus 180° using the phase adjuster.