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US 2001/0017080 A1Published application
Apparatus for controlling polymerized teos build-up in vacuum pump lines
AssigneeMKS Instruments, Inc.
InventorsPaul Dozoretz, Youfan Gu
Life of this patent
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AssigneeMKS Instruments, Inc.
InventorsPaul Dozoretz, Youfan Gu
Estimating the term…
A TEOS trap for controlling TEOS polymerization from reaction furnace effluent in a vacuum pump line a SiO2 CVD process includes a molecular species-selective flow impeding medium that adsorbs and retains TEOS and water molecules from the effluent long enough to consume substantially all the water molecules in TEOS hydrolysis reactions while allowing non-hydrolyzed TEOS, ethylene, and other gaseous byproducts to pass through the trap and retaining solid and liquid phase SiO2-rich TEOS polymers formed by the hydrolysis reactions in the trap for subsequent removal and disposal. The molecular species-selective flow impeding medium has a plurality of adsorption surfaces to make a surface density that performs the TEOS and water flow impeding function and solid and liquid phase TEOS polymer trapping function.
A TEOS trap for preventing build-up of liquid and solid phase SiO2-rich TEOS polymers in a pump line that carries reaction furnace effluent laden with gaseous TEOS and water molecules along with gaseous ethylene and other effluent molecules, comprising:
A trap with a chamber having an inlet and an outlet for removing TEOS from gaseous effluent of a chemical vapor deposition process in which the gaseous effluent comprises water molecules and TEOS molecules, which, when retained together for a sufficient time, undergo hydrolysis to produce polymerized molecular TEOS chains that liquify or solidify and which water molecules and TEOS molecules are polar, thus tend to be adsorbed and retained on surfaces, wherein said trap has a molecular species-selective flow impeding medium positioned in said chamber between said inlet and said outlet with multiple surfaces on which said TEOS molecules and said water molecules can be adsorbed and retained for a sufficient time to facilitate hydrolysis and polymerization of the TEOS molecules while gaseous ethylene and other non-polar molecules pass substantially unimpeded over said surfaces.
Dependencies are inferred from the claim text.