Low thermal expansion clamping mechanism
US5460703A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 3, 1994 |
| Grant date | Oct 24, 1995 |
| Priority date | — |
| Expiry date | Oct 3, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C14/50
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
An improved clamping ring, useful for securing a semiconductor wafer during wafer processing, for example in a physical vapor deposition system, is made of a thermally nonconductive material having a low thermal coefficient of expansion, for example a ceramic material, such as alumina. Such material, by exhibiting only slight expansion or contraction during thermal cycling, allows the production of a clamping ring having the largest possible inner diameter, such that more wafer surface area is available for device fabrication, and such that wafer shadowing that results from metal film build-up on the clamping ring is mitigated, thereby extending the useful life of the clamp ring and reducing system downtime. Additionally, the thermal stability provided by the present invention improves wafer temperature uniformity, and therefore also improves per wafer device yield while increasing device reliability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.