Layer detection for high aspect ratio etch control
US11107738B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 16, 2017 |
| Grant date | Aug 31, 2021 |
| Priority date | — |
| Expiry date | Nov 16, 2037 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10B43/27
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Controlling an etch process applied to a multi-layered structure, by calculating a spectral derivative of reflectance of an illuminated region of interest of a multi-layered structure during an etch process applied to the multi-layered structure, identifying in the spectral derivative a discontinuity that indicates that an edge of a void formed by the etch process at the region of interest has crossed a layer boundary of the multi-layered structure, determining that the crossed layer boundary corresponds to a preselected layer boundary of the multi-layered structure, and applying a predefined control action to the etch process responsive to determining that the crossed layer boundary corresponds to the preselected layer boundary of the multi -layered structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.