Aerogel thin film formation from multi-solvent systems
US6130152A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 14, 1996 |
| Grant date | Oct 10, 2000 |
| Priority date | — |
| Expiry date | Nov 14, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2221/1047
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
This invention pertains generally to precursors and deposition methods suited to aerogel thin film fabrication. An aerogel precursor sol which contains an oligomerized metal alkoxide (such as TEOS), a high vapor pressure solvent (such as ethanol) and a low vapor pressure solvent (such as water and 1-butanol) is disclosed. By a method according to the present invention, such a precursor sol is applied as a thin film to a semiconductor wafer, and the high vapor pressure solvent is allowed to evaporate while evaporation of the low vapor pressure solvent is limited, preferably by controlling the atmosphere adjacent to the wafer. The reduced sol is then allowed to gel at a concentration determined by the ratio of metal.alkoxide to low vapor pressure solvent. One advantage of the present invention is that it provides a stable, spinnable sol for setting film thickness and providing good planarity and gap fill for patterned wafers. In addition, however, the reduced sol may be gelled rapidly from a known sol concentration keyed to the desired final density of the aerogel thin film and largely independent of film thickness and spin conditions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.