Methods and apparatus for simulating interaction of radiation with structures, metrology methods and apparatus, device manufacturing method
US11429763B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 2, 2020 |
| Grant date | Aug 30, 2022 |
| Priority date | — |
| Expiry date | Oct 22, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/20
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Parameters of a structure (900) are measured by reconstruction from observed diffracted radiation. The method includes the steps: (a) defining a structure model to represent the structure in a two- or three-dimensional model space; (b) using the structure model to simulate interaction of radiation with the structure; and (c) repeating step (b) while varying parameters of the structure model. The structure model is divided into a series of slices (a-f) along at least a first dimension (Z) of the model space. By the division into slices, a sloping face (904, 906) of at least one sub-structure is approximated by a series of steps (904′, 906′) along at least a second dimension of the model space (X). The number of slices may vary dynamically as the parameters vary. The number of steps approximating said sloping face is maintained constant. Additional cuts (1302, 1304) are introduced, without introducing corresponding steps.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.