Model pattern simulation of semiconductor wafer processing steps
First Claim
1. A method of specifying a model pattern of a diffracting structure for use in semiconductor metrology, the diffracting structure to be fabricated on a semiconductor substrate employing a lithographic process, the method comprising:
- specifying a series of process steps to be employed in fabrication of a diffracting structure on a semiconductor substrate employing a lithographic process; and
simulating the series of process steps to produce a model pattern of the diffracting structure.
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Abstract
Methods and computer program for determining a model pattern of a diffracting structure for use in semiconductor metrology, in which methods a series of process steps to be employed in fabrication of a diffracting structure, such as a diffracting structure fabricated on a semiconductor substrate employing a lithographic process, are specified, and each such specified process step is successively simulated to produce a model pattern of the diffracting structure. The methods further provides for generation of libraries of model patterns and simulated diffraction signatures based thereon, and optionally further provides for comparing diffraction signatures of measured diffracting structures to simulated diffraction signatures of members of the set of model patterns of the diffracting structure, selection of one or more close match simulated diffraction signatures, and deriving one or more parameters associated with the measured diffracting structures.
59 Citations
43 Claims
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1. A method of specifying a model pattern of a diffracting structure for use in semiconductor metrology, the diffracting structure to be fabricated on a semiconductor substrate employing a lithographic process, the method comprising:
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specifying a series of process steps to be employed in fabrication of a diffracting structure on a semiconductor substrate employing a lithographic process; and
simulating the series of process steps to produce a model pattern of the diffracting structure. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of making a simulated diffraction signal of a diffracting structure fabricated on a semiconductor substrate, the method comprising:
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specifying a series of process steps employed in fabrication of a diffracting structure on a semiconductor substrate;
simulating the series of process steps to produce a model pattern of the diffracting structure;
generating a simulated diffraction signal from the model pattern of the diffracting structure. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A method of making a library of simulated diffraction signals of a diffracting structure fabricated on a semiconductor substrate for use in semiconductor metrology, the method comprising:
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specifying a series of process steps employed in fabrication of a diffracting structure on a semiconductor substrate and associated process variances for each process step;
simulating the series of process steps and associated process variances to produce a set of model patterns of the diffracting structure; and
generating simulated diffraction signals from members of the set of model patterns of the diffracting structure. - View Dependent Claims (14, 15)
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16. A method of making a library of simulated diffraction signals of a diffracting structure fabricated on a semiconductor substrate for use in semiconductor metrology, the method comprising:
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specifying a series of process steps employed in fabrication of a diffracting structure on a semiconductor substrate and one or more associated process variances for each process step;
simulating the series of process steps and one or more associated process variances to produce a set of model patterns of the diffracting structure;
generating simulated diffraction signatures of members of the set of model patterns of the diffracting structure;
obtaining a diffraction signature of the diffracting structure on a semiconductor substrate; and
comparing the diffraction signature of the diffracting structure to the simulated diffraction signatures of members of the set of model patterns of the diffracting structure. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
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34. A method of inferentially measuring at least one parameter associated with a diffracting structure fabricated on a semiconductor substrate by means of a radiation-based tool, the method comprising:
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specifying a series of two or more process steps employed in fabrication of a diffracting structure on a semiconductor substrate and one or more associated process variances for each process step;
simulating the series of process steps and associated process variances to produce a set of model patterns of the diffracting structure;
generating simulated diffraction signatures of members of the set of model patterns of the diffracting structure;
obtaining a diffraction signature of the diffracting structure on a semiconductor substrate by means of a radiation-based tool;
comparing the diffraction signature of the diffracting structure to the simulated diffraction signatures of members of the set of model patterns of the diffracting structure, and selecting a close match simulated diffraction signature; and
deriving at least one parameter associated with the diffracting structure by examination of the model pattern generating a close match simulated diffraction signature. - View Dependent Claims (35)
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36. A computer program, residing on a computer-readable medium, comprising instructions for causing a computer to:
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receive input on a series of process steps employed in fabrication of a diffracting structure on a semiconductor substrate;
determine one or more effects of each of the process steps in the fabrication of the diffracting structure; and
produce a graphic representation of a model pattern derived from the one or more effects of each of the process steps in the fabrication of the diffracting structure.
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37. A graphic user interface method for a generating a graphic model pattern of a diffracting structure fabricated on a semiconductor substrate, the method comprising:
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receiving inputs from a user to select process steps to be employed in modeling fabrication of a diffracting structure on a semiconductor substrate;
providing at least one input to specify an order in which to simulate the selected process steps;
displaying a graphic representation of a model pattern of the diffraction structure derived from one or more effects of each of the process steps in the fabrication of the diffracting structure. - View Dependent Claims (38, 39, 40, 41, 42, 43)
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Specification