US 2022/0067260 A1 · Method and System for Calculating Printed Area Metric Indicative of Stochastic Variations of the Lithographic Process

Abstract

Systems and methods for calculating a printed area metric indicative of stochastic variations of the lithographic process are disclosed. Lithography is a process that uses light to transfer a geometric pattern from a photomask, based on a layout design, to a resist on a substrate. The lithographic process is subject to random stochastic phenomena, with the resulting stochastic randomness potentially becoming a major challenge. To characterize the stochastic phenomena, a printed area metric may be generated analytically (rather than via simulations) and comprise one or more defined moments for a printed area distribution associated with the printed area that are indicative of one or more aspects associated with printing. For example, the printed area metric may be indicative of the likelihood of printing within the printed area or the variance of printing within the printed area due to stochastic randomness in one or both of exposure or resist process.

Claims23

Dependent claims

A method comprising:

defining, by at least one processor of a computer, a printed area comprising a sidelobe printing control domain (SPCD) associated with a layout design, wherein the layout design includes one or more elements corresponding to one or more sub-resolution assist features (SRAFs) to remain unprinted during a lithographic process for imaging part or all of the layout design onto a substrate;
determining, by the at least one processor of the computer, one or more defined moments for a printed area distribution associated with the printed area, wherein the one or more defined moments are indicative of likelihood of printing within the printed area due to stochastic randomness in one or both of exposure or resist process;
and
modifying, by the at least one processor of the computer, at least one aspect in the lithographic process based on the one or more defined moments for the printed area distribution associated with the printed area, which reduces an effect of the stochastic randomness in the lithographic process.

1 more element

A non-transitory machine-readable medium comprising instructions that, when executed by a processor, cause a computing system to perform a method comprising:

defining a printed area comprising a sidelobe printing control domain (SPCD) associated with a layout design that is used for a lithographic process for imaging part or all of the layout design onto a substrate, wherein the layout design includes one or more elements corresponding to one or more sub-resolution assist features (SRAFs) to remain unprinted during the lithographic process;
determining one or more defined moments for a printed area distribution associated with the printed area, wherein the one or more defined moments are indicative of likelihood of printing within the printed area due to stochastic randomness in one or both of exposure or resist process;
and
modifying, based on the one or more defined moments for the printed area distribution associated with the printed area, at least one aspect in the lithographic process, which reduces an effect of the stochastic randomness in the lithographic process.

1 more element

Dependencies are inferred from the claim text.

Method and System for Calculating Printed Area Metric Indicative of Stochastic Variations of the Lithographic Process

Life of this patent

Method and System for Calculating Printed Area Metric Indicative of Stochastic Variations of the Lithographic Process

Life of this patent

Abstract

Claims23