Protective film thickness measuring method
US11892282B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 16, 2022 |
| Grant date | Feb 6, 2024 |
| Priority date | — |
| Expiry date | May 16, 2042 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/20
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A protective film thickness measuring method includes a step of applying light to a top surface of a wafer in a state in which no protective film is formed and measuring a first reflection intensity of the light reflected from the top surface, a step of forming the protective film including a light absorbing material, a step of irradiating the protective film with exciting light of a wavelength at which the light absorbing material fluoresces and measuring a second reflection intensity including fluorescence of the protective film and the light reflected from the top surface, and a step of excluding reflection intensity of patterns formed on the top surface, by subtracting the measured first reflection intensity from the measured second reflection intensity, and calculating fluorescence intensity of the protective film.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.