Method of producing optically flat surfaces on processed silicon wafers
US5160560A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 2, 1988 |
| Grant date | Nov 3, 1992 |
| Priority date | — |
| Expiry date | Jun 2, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/135
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for producing optically flat thin semiconductor wafers (12) bonded to a substrate (16). The wafer (12) is bonded without touching the top surface of the wafer (12). Also, the bond is created without the use of pressure. Electrostatic bonding, or contact bonding or both may be employed. After the wafer (12) is bonded, it is then polished to a desired thickness and flatness. After contact bonding and polishing the wafer (12) may then be removed for further processing. The wafer may then be contact bonded to a final substrate (b 34) or electrostatically bonded to a final substrate (42). The contact bonding technique may also be employed as a means for holding the wafer (12) during precise photolithography. The optical flatness achieved permits improved yields over conventional means for securing wafers during photolithography. The electrostatic bonding technique permits extremely thin optically flat silicon wafers to be produced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.