Abstract: In a lithographic apparatus, a control system is provided to automatically reduce throughput in the event that lens-heating aberrations exceed a certain threshold. The determination of whether lens-heating aberrations will exceed the threshold may be based upon a prediction, e.g. using a lens-heating model, or on measurements taken from a previously exposed substrate. Reduction of throughput of the device manufacture may be effected by reducing beam power or the duty cycle of the apparatus. In a particular embodiment, the time taken for substrate movement between exposure portions is increased.

Abstract: A lithographic projection apparatus is disclosed that includes a predictive system configured to predict changes in projection system aberrations with time with respect to measured aberration values, a modelling system configured to determine an application-specific effect of said predicted projection system aberration changes on at least one parameter of an image for a selected pattern, a control system configured to generate a control signal specific to the selected pattern according to said predicted projection system aberration changes and their application-specific effect on the at least one parameter of the image, and an image adjusting system, responsive to the control signal, to compensate for the application-specific effect of said predicted projection system aberration changes on the image.

Abstract: In a lithographic apparatus, a control system is provided to automatically reduce throughput in the event that lens-heating aberrations exceed a certain threshold. The determination of whether lens-heating aberrations will exceed the threshold may be based upon a prediction, e.g. using a lens-heating model, or on measurements taken from a previously exposed substrate. Reduction of throughput of the device manufacture may be effected by reducing beam power or the duty cycle of the apparatus. In a particular embodiment, the time taken for substrate movement between exposure portions is increased.

Abstract: A mask pattern for imaging a marker structure on a substrate with a lithographic apparatus, the marker structure being configured to determine optical alignment or overlay, includes constituent parts to define the marker structure. The constituent parts include a plurality of segments, each segment having substantially a size of a device feature and a segment shape. The mask pattern includes at least one assist feature located at a critical part of the segment shape. The at least one assist feature has substantially a size below a resolution of the lithographic projection and is configured to counteract optical aberrations or optical limitations generated in the lithographic projection at the critical part.

Abstract: A mask pattern for imaging a marker structure on a substrate with a lithographic apparatus, the marker structure being configured to determine optical alignment or overlay, includes constituent parts to define the marker structure. The constituent parts include a plurality of segments, each segment having substantially a size of a device feature and a segment shape. The mask pattern includes at least one assist feature located at a critical part of the segment shape. The at least one assist feature has substantially a size below a resolution of the lithographic projection and is configured to counteract optical aberrations or optical limitations generated in the lithographic projection at the critical part.

Abstract: A lithographic projection apparatus is disclosed that includes a predictive system configured to predict changes in projection system aberrations with time with respect to measured aberration values, a modelling system configured to determine an application-specific effect of said predicted projection system aberration changes on at least one parameter of an image for a selected pattern, a control system configured to generate a control signal specific to the selected pattern according to said predicted projection system aberration changes and their application-specific effect on the at least one parameter of the image, and an image adjusting system, responsive to the control signal, to compensate for the application-specific effect of said predicted projection system aberration changes on the image.

Abstract: A lithographic projection apparatus is disclosed that includes a predictive system configured to predict changes in projection system aberrations with time with respect to measured aberration values, a modelling system configured to determine an application-specific effect of said predicted projection system aberration changes on at least one parameter of an image for a selected pattern, a control system configured to generate a control signal specific to the selected pattern according to said predicted projection system aberration changes and their application-specific effect on the at least one parameter of the image, and an image adjusting system, responsive to the control signal, to compensate for the application-specific effect of said predicted projection system aberration changes on the image. Adjustments may therefore be determined optimally for a given application.

Abstract: A lithographic projection apparatus includes a measurement system for measuring changes in projection system aberrations with time, and a predictive control system for predicting variation of projection system aberrations with time on the basis of model parameters and for generating a control signal for compensating a time-varying property of the apparatus, such as the OVL values (X-Y adjustment) and the FOC values (Z adjustment) of a lens of the projection system for example. An inline model identification system is provided for estimating model parameter errors on the basis of projection system aberration values provided by the predictive control system and measured projection system aberration values provided by the measurement system, and an updating system utilizes the model parameter errors for updating the model parameters of the predictive control system in order to maintain the time-varying property within acceptable performance criteria.