Glycol-based method for forming a thin-film nanoporous dielectric
US5736425A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 14, 1996 |
| Grant date | Apr 7, 1998 |
| Priority date | — |
| Expiry date | Nov 14, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/02282
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
This invention has enabled a new, simple nanoporous dielectric fabrication method. In general, this invention uses a glycol, such as ethylene glycol, as a solvent. This new method allows both bulk and thin film aerogels to be made without supercritical drying, freeze drying, or a surface modification step before drying. Prior art aerogels have required at least one of these steps to prevent substantial pore collapse during drying. Thus, this invention allows production of nanoporous dielectrics at room temperature and atmospheric pressure, without a separate surface modification step. Although not required to prevent substantial densification, this new method does not exclude the use of supercritical drying or surface modification steps prior to drying. In general, this new method is compatible with most prior art aerogel techniques. Although this new method allows fabrication of aerogels without substantial pore collapse during drying, there may be some permanent shrinkage during aging and/or drying.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.