UV-enhanced oxy-nitridation of semiconductor substrates
US6706643B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 8, 2002 |
| Grant date | Mar 16, 2004 |
| Priority date | — |
| Expiry date | Jan 8, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/693
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The oxynitride or oxide layer is formed on a semiconductor substrate by subjecting the substrate to UV radiation while exposed to a gaseous atmosphere of O2 and one or more of N2, N2O, H2 and NH3. Thereafter, a silicon nitride layer is formed according to known 4-step gate stack dielectric processing techniques. Alternatively, a 3-step gate stack process is used, namely following UV-oxidation, a further UV-radiation in NH3 may be applied, followed by a rapid thermal anneal process in an inert ambient. By using UV-oxidation as the first step in either a 4-step or 3-step gate stack process, very thin composite dielectric films with equivalent oxide thickness (EOT) below 16 å and as low as 14.2 å can be obtained with significant improvement in leakage current density.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.