Tungsten CMP with improved alignment mark integrity, reduced edge residue, and reduced retainer ring notching
US6468136B1 · kind B1 · utility
12Cited by
8References
21Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 30, 2000 |
| Grant date | Oct 22, 2002 |
| Priority date | — |
| Expiry date | Jun 30, 2020 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB24B37/32
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Tungsten CMP is conducted with improved alignment mark integrity and reduced edge residue by employing a retaining ring having a mechanical hardness greater than about 85 durometer and a relatively soft polishing pad. Embodiments of the present invention include conducting CMP employing a carrier comprising a retaining ring additionally having a wear rate during CMP of less than about 1 mil per hour and a polishing pad having a hardness less than about 60 durometer. Suitable retaining ring materials include ceramics, quartz, polymers and fiber reinforced polymers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.