Layer detection for high aspect ratio etch control
US11929291B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 23, 2021 |
| Grant date | Mar 12, 2024 |
| Priority date | — |
| Expiry date | Dec 24, 2041 |
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.