Patent ID: 7623218
Filing Date: 2009-11-24
Classification: G03F

Abstract:
1. A lithographic method of manufacturing a miniaturized device using a projection exposure system of the liquid immersion type, the method comprising: disposing a patterning structure to be imaged in a region of an object plane of an imaging optics of the projection exposure system; disposing a substrate carrying a resist in a region of an image plane of the imaging optics and exposing portions of the substrate with images of the patterning structure using the projection exposure system; maintaining, at least during selected time intervals, a flow of an immersion liquid to and from a space between the substrate and a front lens of the imaging optics closest to the substrate; measuring a physical property which is indicative of at least one of a refractive index of the immersion liquid and a change of the refractive index of the immersion liquid over time, wherein the physical property is measured using a beam of measuring light interacting with the immersion liquid; measuring a first physical property using a first beam of measuring light interacting with the immersion liquid at a location upstream of the space between the substrate and the front lens; measuring a second physical property using a second beam of measuring light interacting with the immersion liquid at a location downstream of the space between the substrate and the front lens; adjusting at least one optical property of the projection exposure system based on the measured physical property, the measured first physical property, and the measured second physical property; exposing further portions of the substrate with images of the patterning structure using the projection exposure system with the at least one adjusted optical property of the projection exposure system; and developing the exposed resist and processing the substrate with the developed resist.