Patent ID: 9052609
Filing Date: 2015-06-09
Classification: G03F

Abstract:
1. A projection exposure apparatus for microlithography comprising: an illumination system configured to illuminate a mask in an object field with exposure light; and a projection objective comprising multiple optical elements configured to image the exposure light from the mask in the object field to a wafer in an image field, wherein the projection exposure apparatus is a wafer scanner configured to move the wafer relative to the mask during an exposure of a single die of the wafer with the exposure light, wherein the projection objective further comprises at least one manipulator configured to manipulate at least one of the optical elements and a control unit configured to control the manipulator to manipulate the optical element according to a repeating cycle having a time interval of less than 1000 ms, wherein the control unit comprises a determining unit configured to determine information about an imaging aberration, wherein the imaging aberration is caused by heating within the projection exposure apparatus during the exposure of the single die of the wafer with the exposure light as the wafer scanner moves the wafer relative to the mask, and wherein the control unit is configured to manipulate the optical element with the manipulator during the exposure of the single die of the wafer with the exposure light to reduce the imaging aberration based on information comprising the information determined by the determining unit.