Ceramic sintered product and process for producing the same
US6265334A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 22, 1998 |
| Grant date | Jul 24, 2001 |
| Priority date | — |
| Expiry date | Oct 22, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Low thermal expansion ceramics contains a cordierite crystal phase, wherein a phase of a crystalline compound containing at least one element selected from the group consisting of an alkaline earth element other than Mg, a rare earth element, Ga and In, is precipitated in the grain boundaries of said crystal phase, said ceramics has a relative density of not smaller than 95%, a coefficient of thermal expansion of not larger than 1.times.10.sup.-6 /.degree. C. at 10 to 40.degree. C., and a Young's modulus of not smaller than 130 GPa. That is, the ceramics has a small coefficient of thermal expansion, is deformed very little depending upon a change in the temperature, has a very high Young's modulus and is highly rigid and is resistance against external force such as vibration. Accordingly, the ceramics is very useful as a member for supporting a wafer or an optical system is a lithography apparatus that forms high resolution circuit patterns on a silicon wafer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.