Calibration of lithographic process models
US8174681B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 6, 2009 |
| Grant date | May 8, 2012 |
| Priority date | — |
| Expiry date | Sep 22, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/705
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method is provided for calibrating a model of a lithographic process that includes defining a parameter space of lithographic model parameters that are expected in an integrated circuit layout. The parameter space is defined according to bin values of a lithographic model parameter that span the range from a predetermined minimum and maximum value of the model parameter. The bin values may be incremented uniformly between the maximum and minimum parameter values, or may be distributed according to a weighting. The lithographic model is calibrated to an initial calibration test pattern. The resulting simulated calibration pattern is evaluated to determine whether the model parameter space is adequately populated. If the parameter space is over or under populated, the calibration pattern is modified until the calibration pattern test values adequately populate the parameter space, so that the final calibrated lithographic process model will more reliably predict images over the full range of image parameters.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.