Polishing pad with multipurpose composite window
US11325221B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 9, 2018 |
| Grant date | May 10, 2022 |
| Priority date | — |
| Expiry date | Nov 7, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/30625
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
The invention provides a polishing pad suitable for polishing integrated circuit wafers. It includes an upper polishing layer that having a polishing surface and at least one groove in the upper polishing layer. At least one transparent window is located within the upper layer. The at least one transparent window has a thickness greater than a desired wear depth of the at least one groove. The at least one transparent window includes a non-fluorescent transparent polymer; and a fluorescent transparent polymer. The transparent window allows measuring groove depth by activating the fluorescent transparent polymer with an activation source at a wavelength sufficient to excite the fluorescent transparent polymer and allow endpoint detection by sending light through the fluorescent transparent polymer and the non-fluorescent transparent polymer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.