Abstract: During the conventional temperature swing adsorption (TSA) process, NF3 co-adsorbed with the impurities is vented during regeneration. This invention is a novel TSA cycle in which the co-adsorbed NF3 is recovered. In this novel TSA cycle, a control scheme is used to stop the adsorption prior to the saturation of the adsorber with impurities and use a recovery purge gas (either co-current or counter-current) to release the co-adsorbed NF3 off the saturated adsorber. The effluent of the inert purge gas can be combined with the effluent of the on-stream vessel or can be recycled to the feed of the on-stream vessel. 10%-100% of the co-adsorbed NF3 is recovered and made available as product in this novel TSA cycle. Thus the overall process yield of NF3 is increased. The removing of the co-adsorbed NF3 from the adsorber also prevents adsorber degradation thus prolonging the useful life of the adsorber.

Abstract: During the conventional temperature swing adsorption (TSA) process, NF3 co-adsorbed with the impurities is vented during regeneration. This invention is a novel TSA cycle in which the co-adsorbed NF3 is recovered. In this novel TSA cycle, a control scheme is used to stop the adsorption prior to the saturation of the adsorber with impurities and use a recovery purge gas (either co-current or counter-current) to release the co-adsorbed NF3 off the saturated adsorber. The effluent of the inert purge gas can be combined with the effluent of the on-stream vessel or can be recycled to the feed of the on-stream vessel. 10%-100% of the co-adsorbed NF3 is recovered and made available as product in this novel TSA cycle. Thus the overall process yield of NF3 is increased. The removing of the co-adsorbed NF3 from the adsorber also prevents adsorber degradation thus prolonging the useful life of the adsorber.

Abstract: This invention is directed to an improvement in a wet chemical process for producing electronic precursors. In such process a silicon surface is treated with a wet chemical and the wet chemical subsequently removed therefrom by contact with a drying vapor. In this case, the improvement in the process comprises: employing a drying vapor comprised of isopropanol; and, maintaining the isopropanol employed in said drying vapor at a temperature below about 80° F. prior to forming said drying vapor. Preferably the isopropanol is maintained free from exposure to light from the time of manufacture to the time of use.