Abstract: This invention has enabled a new, simple nanoporous dielectric fabrication method. In general, this invention uses a polyol, such as glycerol, 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.

Abstract: This invention pertains generally to aging methods suited to aerogel thin film fabrication, and particularly to techniques for improving gel strength and/or aerogel dielectric constant by a rapid aging technique, which avoid damage or premature drying of wet gel thin films during aging. A substrate having a wet gel thin film deposited thereon is contacted with a saturated water vapor atmosphere, preferably at an elevated pressure and a temperature greater than 100.degree. C. The method may comprise a vapor-phase exchange step to remove low boiling point pore liquids such as ethanol prior to or during aging. The method may also comprise a vapor-phase exchange step to replace water in the wet gel with another pore liquid such as acetone to stop the aging process and prepare the wet gel for drying. A vapor-phase aging catalyst (e.g. ammonia) may also be used to enhance the aging process.

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.