Abstract: A lithographic apparatus comprising a projection system comprising at least one optical component and configured to project a pattern onto a substrate. The lithographic apparatus further comprises a control system arranged to reduce the effects of heating and/or cooling of an optical component in a lithographic process. The control system is configured at least: to select at least one of a plurality of mode shapes to represent a relationship between at least one input in the lithographic process and an aberration resulting from the input and to generate and apply a correction to the lithographic apparatus based on the mode shape.

Abstract: A lithographic apparatus comprising a projection system comprising at least one optical component and configured to project a pattern onto a substrate. The lithographic apparatus further comprises a control system arranged to reduce the effects of heating and/or cooling of an optical component in a lithographic process. The control system is configured at least: to select at least one of a plurality of mode shapes to represent a relationship between at least one input in the lithographic process and an aberration resulting from the input and to generate and apply a correction to the lithographic apparatus based on the mode shape.

Abstract: A method of reducing an aberration arising during operation of a lithographic apparatus, the method comprising measuring the aberration to obtain an aberration signal, the aberration signal comprising a first component and a second component, wherein the first component of the aberration signal comprises a first frequency band and the second component of the aberration signal comprises a second frequency band, wherein the first frequency band comprises frequencies that are higher than frequencies comprised in the second frequency band, calculating a correction, wherein a first part of the correction is calculated based on the first component of the aberration signal, and applying the correction to the lithographic apparatus.

Abstract: A method of reducing an aberration arising during operation of a lithographic apparatus, the method comprising measuring the aberration to obtain an aberration signal, the aberration signal comprising a first component and a second component, wherein the first component of the aberration signal comprises a first frequency band and the second component of the aberration signal comprises a second frequency band, wherein the first frequency band comprises frequencies that are higher than frequencies comprised in the second frequency band, calculating a correction, wherein a first part of the correction is calculated based on the first component of the aberration signal, and applying the correction to the lithographic apparatus.

Abstract: A method of reducing effects of reticle heating and/or cooling in a lithographic process, the method including calibrating a linear time invariant reticle heating model using a system identification method; predicting distortions of the reticle using the reticle heating model and inputs in the lithographic process; and calculating and applying a correction in the lithographic process on the basis of the predicted distortions of the reticle.

Abstract: A method of reducing effects of reticle heating and/or cooling in a lithographic process, the method including calibrating a linear time invariant reticle heating model using a system identification method; predicting distortions of the reticle using the reticle heating model and inputs in the lithographic process; and calculating and applying a correction in the lithographic process on the basis of the predicted distortions of the reticle.

Abstract: A method of reducing an aberration of a lithographic apparatus, the method including measuring the aberration, taking the measured aberration into account, estimating a state of the lithographic apparatus, calculating a correction using the estimated state, and applying the correction to the lithographic apparatus.

Abstract: A method of reducing effects of reticle heating and/or cooling in a lithographic process, the method including calibrating a linear time invariant reticle heating model using a system identification method; predicting distortions of the reticle using the reticle heating model and inputs in the lithographic process; and calculating and applying a correction in the lithographic process on the basis of the predicted distortions of the reticle.

Abstract: A method of reducing effects of reticle heating and/or cooling in a lithographic process, the method including calibrating a linear time invariant reticle heating model using a system identification method; predicting distortions of the reticle using the reticle heating model and inputs in the lithographic process; and calculating and applying a correction in the lithographic process on the basis of the predicted distortions of the reticle.

Abstract: A method of reducing effects of reticle heating and/or cooling in a lithographic process, the method including calibrating a linear time invariant reticle heating model using a system identification method; predicting distortions of the reticle using the reticle heating model and inputs in the lithographic process; and calculating and applying a correction in the lithographic process on the basis of the predicted distortions of the reticle.

Abstract: A method of reducing an aberration of a lithographic apparatus, the method including measuring the aberration, taking the measured aberration into account, estimating a state of the lithographic apparatus, calculating a correction using the estimated state, and applying the correction to the lithographic apparatus.