Core configuration for in-situ electromagnetic induction monitoring system
US11638982B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 6, 2019 |
| Grant date | May 2, 2023 |
| Priority date | — |
| Expiry date | Oct 5, 2041 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/26
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus for chemical mechanical polishing includes a support for a polishing pad having a polishing surface, and an electromagnetic induction monitoring system to generate a magnetic field to monitor a substrate being polished by the polishing pad. The electromagnetic induction monitoring system includes a core and a coil wound around a portion of the core. The core includes a back portion, a center post extending from the back portion in a first direction normal to the polishing surface, and an annular rim extending from the back portion in parallel with the center post and surrounding and spaced apart from the center post by a gap. A width of the gap is less than a width of the center post, and a surface area of a top surface of the annular rim is at least two times greater than a surface area of a top surface of the center post.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.