Silicon fixtures for supporting wafers during thermal processing
US6450346B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 2000 |
| Grant date | Sep 17, 2002 |
| Priority date | — |
| Expiry date | Jun 30, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/67306
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A silicon tower or boat for removably supporting a plurality of silicon wafers during thermal processing. A preferred embodiment of the tower includes four legs secured on their ends to two bases. A plurality of slots are cut in the legs allowing slidable insertion of the wafers and support for them. The legs preferably have a rounded wedge shape with a curved front surface of small radius cut with the slots and a back surface that is either flat or curved with a substantially larger radius. Preferably, the legs are machined from virgin polysilicon formed by chemical vapor deposition from silane. The bases may be either virgin poly or monocrystalline silicon and be either integral or composed of multiple parts. Virgin polysilicon is preferably annealed to above 1025° C. before machining. Silicon parts may be joined by applying a spin-on glass between the parts and annealing the assembly. After assembly, the surface of a tower is subjected to sub-surface working.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.