Low temperature silicon nitride CVD process
US4720395A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 25, 1986 |
| Grant date | Jan 19, 1988 |
| Priority date | — |
| Expiry date | Aug 25, 2006 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C16/345
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Thermal CVD process for forming Si.sub.3 N.sub.4 -type films on substrates by reaction of gaseous NF.sub.3 with gaseous disilane at a temperature in the range of 250.degree.-500.degree. C., at pressures of 0.1-10 Torr. The mole ratio of NF.sub.3 to silane is in the range of 0.5-3.0 and the reaction zone is preferably isothermal (T controlled to within .sup.+ 5.degree. C.). The resulting films have RI's in the range of 1.4 to 3.0. The process parameters can be controlled to dope the film with H and/or F, or to create zones of differing properties within the film. The process does not cause radiation damage, metal migration, stored charge dissipation or high levels of impurities. Control of distance between adjacent wafers and wafer-to-wall spacing combined with laminar gas flow gives excellent film thickness uniformity, on the order of below about .+-.5% across the wafer face, both within (across) wafers and from wafer to wafer (batch uniformity).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.