Method of making bonded wafers
US5514235A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 17, 1994 |
| Grant date | May 7, 1996 |
| Priority date | — |
| Expiry date | Jun 17, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/135
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method is disclosed for obtaining bonded wafers of SOI type, where impurity redistribution in the bulk of the wafers is suppressed and the bonding strength between the wafers is substantially higher compared with that in the prior art. This is accomplished by forming a thermally grown oxide layer on the surface of the thinner one(bond wafer) of two monocrystalline silicon wafers having thicknesses different from each other by more than 50 .mu.m; then superposing the thinner wafer onto the other thicker wafer(base wafer); and finally conducting at least two heat treatments of the wafers at temperatures selected in the range of under 900.degree. C. for a period of time selected in the range of from 0.5 min. to 120 min.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.