Methods of tuning process models
AssigneeASML Netherlands B.V.
InventorsMu Feng, Mir Farrokh Shayegan Salek, Dianwen Zhu, Leiwu Zheng, Rafael C. Howell, Jen-Shiang Wang
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Abstract
Methods of constructing a process model for simulating a characteristic of a product of lithography from patterns produced under different processing conditions. The methods use a deviation between the variation of the simulated characteristic and the variation of the measured characteristic to adjust a parameter of the process model.
Claims20
A method comprising:
- obtaining simulated characteristics by simulating, by a hardware computer system and under a plurality of processing conditions, characteristics of a product of lithography using a process model comprising a parameter;
- determining a statistical variation of the simulated characteristics;
- obtaining measured characteristics by measuring the characteristics of the product, from patterns produced under the plurality of processing conditions;
- determining a statistical variation of the measured characteristics;
- determining a first deviation between the statistical variation of the simulated characteristics and the statistical variation of the measured characteristics;
- and
- adjusting the parameter based on the first deviation.
A method comprising:
- obtaining a plurality of first deviations, each of which being between a statistical variation of simulated characteristics of a product of lithography and a statistical variation of measured characteristics of the product of lithography, wherein the simulated characteristics are obtained by simulating, by a hardware computer system, characteristics of the product using a process model comprising a parameter;
- constructing a plurality of cost functions, the cost functions being combinations of the plurality of first deviations;
- and
- adjusting the parameter of the process model by using the cost functions.
A non-transitory computer-readable medium comprising instructions therein, the instructions, upon execution by a computer system, configured to cause the computer system to at least:
- obtain a plurality of first deviations, each of which being between a statistical variation of simulated characteristics of a product of lithography and a statistical variation of measured characteristics of the product of lithography, wherein the simulated characteristics are obtained by simulating, by a hardware computer system, characteristics of the product using a process model comprising a parameter;
- construct a plurality of cost functions, the cost functions being combinations of the plurality of first deviations;
- and
- adjust the parameter of the process model by using the cost functions.
A non-transitory computer-readable medium comprising instructions therein, the instructions, upon execution by a computer system, configured to cause the computer system to at least:
- obtain simulated characteristics by computer simulation, under a plurality of processing conditions, of characteristics of a product of lithography using a process model comprising a parameter;
- determine a statistical variation of the simulated characteristics;
- obtain measured characteristics by measuring the characteristics of the product, from patterns produced under the plurality of processing conditions;
- determine a statistical variation of the measured characteristics;
- determine a deviation between the statistical variation of the simulated characteristics and the statistical variation of the measured characteristics;
- and
- adjust the parameter based on the deviation.
Dependencies are inferred from the claim text.