Method for adaptive feedback controlled polishing
US9573243B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 4, 2014 |
| Grant date | Feb 21, 2017 |
| Priority date | — |
| Expiry date | Nov 4, 2034 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB81C2201/0104
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An adaptive feedback control method is provided for a chemical mechanical polish process to minimize a dielectric layer clearing time difference between two annular regions on a substrate. An optical system with an optical window passes below the polishing pad and detects reflected light interference signals from at least two annular regions. A pre-clearing time difference is determined and is used to calculate an adjustment to one or both of a CMP head membrane pressure and a retaining ring pressure. The pressure adjustment is applied before the end of the polish cycle to avoid the need for a second polish cycle and to reduce a dishing difference and a resistance difference in a metal layer in the at least two annular regions. In some embodiments, a second pressure adjustment is performed before the end of the cycle and different CMP head membrane pressure adjustments are made in different pressure zones.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.