Optimization of lithographic process based on bandwidth and speckle

A non-transitory computer-readable medium comprising instructions stored therein that, when executed by one or more processors, are configured to cause the one or more processors to at least:

• compute a multi-variable cost function, the multi-variable cost function being a function of:
• (i) a plurality of design variables that affect characteristics of a lithographic process of imaging a portion of a design layout onto a substrate using a lithographic apparatus and (ii) a radiation bandwidth of a radiation source of the lithographic apparatus;
• and
• reconfigure one or more of the characteristics of the lithographic process by adjusting one or more of the design variables to reduce or minimize a speckle characteristic associated with the radiation generation by the radiation source, while maintaining an image contrast associated with the lithographic process within a desired range, the speckle characteristic is reduced by increase of the radiation bandwidth.

A method comprising:

• computing, by a hardware computer system, a multi-variable cost function, the multi-variable cost function being a function of:
• (i) a plurality of design variables that affect characteristics of a lithographic process of imaging a portion of a design layout onto a substrate using a lithographic apparatus and (ii) a radiation bandwidth of a radiation source of the lithographic apparatus;
• and
• determining, by the hardware computer system, an optimal radiation bandwidth to improve the lithographic process by adjusting one or more design variables until a termination condition is satisfied, the termination condition including a speckle characteristic being within a speckle specification associated with the radiation generation by the radiation source, while maintaining an image contrast associated with the lithographic process within a desired range, the speckle characteristic being reduced by increase of the radiation bandwidth.

A non-transitory computer-readable medium comprising instructions stored therein that, when executed by one or more processors, are configured to cause the one or more processors to at least:

• compute a multi-variable cost function, the multi-variable cost function being a function of:
• (i) a plurality of design variables that affect characteristics of a lithographic process of imaging a portion of a design layout onto a substrate using a lithographic apparatus and (ii) a radiation bandwidth of a radiation source of the lithographic apparatus;
• and
• determine an optimal radiation bandwidth to improve the lithographic process by adjusting one or more design variables until a termination condition is satisfied, the termination condition including a speckle characteristic being within a speckle specification associated with the radiation generation by the radiation source, while maintaining an image contrast associated with the lithographic process within a desired range, the speckle characteristic being reduced by increase of the radiation bandwidth.