Method for process metrology
AssigneeASML Netherlands B.V.
InventorsBert Verstraeten, Hugo Augustinus Joseph Cramer, Thomas Theeuwes
Life of this patent
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Abstract
A method of evaluating a patterning process, the method including: obtaining the result of a first measurement of a first metrology target; obtaining the result of a second measurement of a second metrology target, the second metrology target having a structural difference from the first metrology target that generates a sensitivity difference and/or an offset, of a process parameter of the patterning process between the first and second metrology targets; and determining a value pertaining to the patterning process based on the results of the first and second measurements.
Claims20
A method of generating a set of metrology targets to evaluate a patterning process, the method comprising:
- obtaining a pattern target;
- and
- generating, by a computer system, a first metrology target from the pattern target, the first metrology target having a structural difference from the pattern target that generates a sensitivity difference and/or an offset, of a process parameter of the patterning process between the pattern target and the first metrology target such that a Bossung curve measured for the first metrology target is shifted from a Bossung curve measured for the pattern target.
A non-transitory computer program product comprising machine-readable instructions therein, the instructions, when executed, are configured to cause a processor system to at least:
- obtain a pattern target;
- and
- generate a first metrology target to evaluate a patterning process from the pattern target, the first metrology target having a structural difference from the pattern target that generates a sensitivity difference and/or an offset, of a process parameter of the patterning process between the pattern target and the first metrology target such that a Bossung curve measured for the first metrology target is shifted from a Bossung curve measured for the pattern target.
A non-transitory set of metrology targets to evaluate a patterning process, the set of metrology targets comprising a first metrology target and a second metrology target, a difference between the first metrology target and the second metrology target generating a sensitivity difference and/or an offset, of a process parameter of the patterning process between the first and second metrology targets, wherein the offset represents a difference in formation of the first and second metrology targets when subject to a particular same value of the process parameter.
Dependencies are inferred from the claim text.