Lithographic apparatus and method for optimizing an illumination source using photolithographic simulations
AssigneeASML Netherlands B.V.
InventorSteven George Hansen
Life of this patent
Estimating the term…
Abstract
A method for optimizing the illumination conditions of a lithographic apparatus by computer simulation, the lithographic apparatus including an illuminator and a projection system, includes defining a lithographic pattern to be printed on the substrate, selecting a simulation model, selecting a grid of source points in a pupil plane of the illuminator, calculating separate responses for individual source points, each of the responses representing a result of a single or series of simulations using the simulation model, and adjusting an illumination arrangement based on analysis of accumulated results of the separate calculations.
Claims59
A method for optimizing the conditions of illumination of a lithographic apparatus by computer simulation, the lithographic apparatus comprising an illuminator and a projection system, the method comprising:
- defining a lithographic pattern to be printed on a substrate;
- selecting a simulation model;
- selecting a grid of source points in a pupil plane of the illuminator;
- calculating separate responses for individual source points, each of the responses representing a result of a single or series of simulations using the simulation model;
- and
- adjusting an illumination arrangement of the illuminator based on analysis of accumulated results of the separate calculations.
A lithographic projection apparatus comprising:
- an illumination system to provide a projection beam of radiation
- a support structure to support a patterning structure which can be used to pattern the projection beam according to a desired pattern;
- a substrate table to hold a substrate;
- a projection system to project the patterned beam onto a target portion of the substrate;
- a processor to define a lithographic pattern to be printed on the substrate, select a grid of source points in a pupil plane of the illumination system, calculate separate responses for individual source points, each of the responses representing a result of a single or series of simulations using a simulation model, and calculate an optimized illumination arrangement based on analysis of the accumulated results of the separate calculations;
- and
- a selectably variable beam controller that is adapted to modify a cross-sectional intensity distribution in the projection beam exiting the illumination system in accordance with the optimized illumination arrangement calculated by the processor.
A machine readable medium encoded with machine executable instructions for optimizing an illumination arrangement of an illuminator according to a method comprising:
- defining a lithographic pattern to be printed on a substrate;
- selecting a simulation model;
- selecting a grid of source points in a pupil plane of the illuminator;
- calculating separate responses for individual source points, each of the responses representing a result of a single or series of simulations using the simulation model;
- and
- adjusting the illumination arrangement based on analysis of accumulated results of the separate calculations.
A device manufacturing method, comprising:
- projecting a patterned beam of radiation onto a target portion of a layer of radiation-sensitive material on a substrate, wherein, prior to impinging the mask, a cross-sectional intensity distribution in the projection beam is optimized using a method comprising:
- defining a lithographic pattern to be printed on the substrate;
- selecting a simulation model;
- selecting a grid of source points in a pupil plane of an illuminator;
- calculating separate responses for individual source points, each of the responses representing a result of a single or series of simulations using the simulation model;
- and
- adjusting an illumination arrangement of the illuminator based on analysis of accumulated results of the separate calculations.
Dependencies are inferred from the claim text.