Etching apparatus and etching method and detecting apparatus of film thickness
US11239097B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 8, 2019 |
| Grant date | Feb 1, 2022 |
| Priority date | — |
| Expiry date | Feb 20, 2039 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/334
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
In thickness/depth measurement of a wafer in etching, variation occurs in detected light quantity due to fluctuation of light quantity of a light source or fluctuation of air in a region through which light passes, and measurement accuracy of thickness/depth is reduced, and thus the total light quantity or average light quantity of an arbitrary wavelength is calculated from an optical spectrum measured at each time instant during etching, estimated total light quantity or estimated average light quantity at the present time, which is estimated using total light quantity or average light quantity measured prior to the present time, is calculated, a change rate, as a ratio of the total light quantity at the present time to the estimated total light quantity or a ratio of the average light quantity to the estimated average light quantity, is calculated, the calculated change rate is used to correct light quantity of each wavelength at the present time, and the corrected light quantity of each wavelength is used to perform thickness/depth measurement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.