Aluminum metaphosphate dopant sources
US3998668A · kind A · utility
9Cited by
4References
18Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 18, 1976 |
| Grant date | Dec 21, 1976 |
| Priority date | — |
| Expiry date | Mar 18, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S252/951
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A solid source consisting essentially of high purity aluminum metaphosphate, Al(PO.sub.3).sub.3 is used for introducing elemental phosphorus into P-type silicon chips or wafers of semi-conductor grade. The aluminum metaphosphate functions as a source for the controlled release of P.sub.2 O.sub.5 vapors which are directed to the desired face of the silicon wafer. The reverse side of the silicon wafer receives little or no phosphorus and consequently retains its character as P-type silicon.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.