A method and apparatus for predicting aberrations in a projection system
AssigneeASML Netherlands B.V.
InventorsMhamed AKHSSAY, Laurentius Johannes Adrianus VAN BOKHOVEN
Life of this patent
Estimating the term…
Abstract
A method of predicting thermally induced aberrations of a projection system for projecting a radiation beam, the method comprising: calculating a change in temperature of the projection system from a power of the radiation beam output from the projection system using a dynamic linear function; and calculating the thermally induced aberrations from the calculated change in temperature using a static non-linear function.
Claims18
1-17. (canceled)
A method comprising:
- calculating a change in temperature of a projection system from a power of a radiation beam output from a projection system using a dynamic linear function;
- and
- calculating a thermally induced aberrations from the calculating using a static non-linear function.
A method comprising:
- adjusting a lithographic apparatus to compensate for thermally induced aberrations and/or drift of thermally induced aberrations of a projection system of the lithographic apparatus based on operations using predicted aberrations by:
- calculating a change in temperature of a projection system from a power of a radiation beam output from a projection system using a dynamic linear function, and
- calculating a thermally induced aberrations from the calculating using a static non-linear function
- wherein the adjusting is performed in a control loop system.
A lithographic apparatus comprising:
- a projection system configured to project a radiation beam to project a pattern from a patterning device onto a substrate, wherein the lithographic apparatus is configured to predict thermally induced aberrations of the projection system by:
- using a dynamic linear function to calculate a change in temperature of the projection system from a power of the radiation beam output from the projection system using a dynamic linear function, and
- using a static non-linear function to calculate the thermally induced aberrations from the calculated change in temperature.
A computer program comprising computer readable instructions configured to cause a processor to carry out operations comprising:
- calculating a change in temperature of a projection system from a power of a radiation beam output from a projection system using a dynamic linear function;
- and
- calculating a thermally induced aberrations from the calculating using a static non-linear function.
A computer readable medium carrying a computer program that causes a processor to perform operations comprising:
- calculating a change in temperature of a projection system from a power of a radiation beam output from a projection system using a dynamic linear function;
- and
- calculating a thermally induced aberrations from the calculating using a static non-linear function.
A computer apparatus comprising:
- a memory storing processor readable instructions;
- and
- a processor arranged to read and execute instructions stored in the memory, wherein the processor readable instructions comprise instructions arranged to control the computer to carry out operations comprising:
- calculating a change in temperature of a projection system from a power of a radiation beam output from a projection system using a dynamic linear function;
- and
- calculating a thermally induced aberrations from the calculating using a static non-linear function.
Dependencies are inferred from the claim text.