Pre-thermal treatment cleaning process
US5712198A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 7, 1995 |
| Grant date | Jan 27, 1998 |
| Priority date | — |
| Expiry date | Dec 7, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/974
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Process for heat-treating a silicon wafer which includes the steps of contacting the surface of the silicon wafer with an aqueous solution containing hydrofluoric acid to remove metals from the wafer surface, contacting the hydrofluoric acid treated wafers with ozonated water to grow a hydrophilic oxide layer on the surface of the silicon wafer, and heating the ozonated water treated wafers to a temperature of at least about 300.degree. C. for a duration of at least about 1 second. The concentration of each of iron, chromium, calcium, titanium, cobalt, manganese, zinc and vanadium, on the surface of the silicon wafer at the initiation of the heating being less than 1.times.10.sup.9 atoms/cm.sup.2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.