Abstract: This invention has enabled a new, simple thin film nanoporous dielectric fabrication method. In general, this invention uses glycerol, or another low volatility compound, as a solvent. This new method allows thin film aerogels/low density xerogels to be made without supercritical drying, freeze drying, or a surface modification step before drying. Thus, this invention allows production of nanoporous dielectrics at room temperature and atmospheric pressure, without a separate surface modification step. 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. This invention allows controlled porosity thin film nanoporous aerogels to be deposited, gelled, aged, and dried without atmospheric controls.

Abstract: This invention has enabled a new, simple thin film nanoporous dielectric fabrication method. In general, this invention uses glycerol, or another low volatility compound, as a solvent. This new method allows thin film aerogels/low density xerogels 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. 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. This invention allows controlled porosity thin film nanoporous aerogels to be deposited, gelled, aged, and dried without atmospheric controls.

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.

Abstract: This invention has enabled a new, simple thin film nanoporous dielectric fabrication method. In general, this invention uses glycerol, or another low volatility compound, as a solvent. This new method allows thin film aerogels/low density xerogels to be made without supercritical drying, freeze drying, or a surface modification step before drying. Thus, this invention allows production of nanoporous dielectrics at room temperature and atmospheric pressure, without a separate surface modification step. 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. This invention allows controlled porosity thin film nanoporous aerogels to be deposited, gelled, aged, and dried without atmospheric controls.

Abstract: This pertains generally to precursors and deposition methods suited to aerogel thin film fabrication of nanoporous dielectrics. An aerogel precursor sol is disclosed. This aerogel precursor sol contains a metal alkoxide (such as TEOS) and a solvent, but no gelation catalyst. By a method according to the present invention, such a precursor sol is applied as a nongelling thin film 14 to a semiconductor substrate 10. This substrate may contain patterned conductors 12, gaps 13, or other structures. An independent gelation catalyst (preferably, vapor phase ammonia) is added to promote rapid gelation of the thin film sol 14 at the desired time. One advantage is that it allows substantially independent control of gelation and pore fluid evaporation. This independent catalyst introduction allows additional processing steps to be performed between sol deposition and the onset of substantial gelation. One potential step is to evaporate a portion of the pore fluid solvent.

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.

Abstract: This pertains generally to precursors and deposition methods suited to aerogel thin film fabrication of nanoporous dielectrics. A method of forming a nanoporous dielectric on a semiconductor substrate is disclosed. By a method according to the present invention, a precursor sol is applied as a nongelling thin film 14 to a semiconductor substrate 10. This substrate may contain patterned conductors 12, gaps 13, and/or other structures. A portion of the solvent is evaporated from the thin film 14 to produce a reduced thickness film 18. Film 18 is gelled and may be aged. A surface modification agent is introduced to the reaction atmosphere in a vaporish form, e.g., a vapor, mist, aerosol, or similar form. The surface modifier can then diffuse into, condense onto, and/or settle onto the wet gel and then diffuse throughout the thin film. This vaporish introduction of the surface modification agent ensures that there are no strong fluid flows across the wafer that might damage the wet gel.

Abstract: This invention has enabled a new, simple thin film nanoporous dielectric fabrication method. In general, this invention uses glycerol, or another low volatility compound, as a solvent. This new method allows thin film aerogels/low density xerogels to be made without supercritical drying, freeze drying, or a surface modification step before drying. Thus, this invention allows production of nanoporous dielectrics at room temperature and atmospheric pressure, without a separate surface modification step. 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. This invention allows controlled porosity thin film nanoporous aerogels to be deposited, gelled, aged, and dried without atmospheric controls.

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.