Super critical drying of low k materials
AssigneeAdvanced Micro Devices, Inc.
InventorsBharath Rangarajan, Ramkumar Subramanian, Bhanwar Singh
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Abstract
One aspect of the present invention relates to a method of forming a low k material layer on a semiconductor substrate, involving the steps of depositing a mixture containing a low k material and a casting solvent on the semiconductor substrate; optionally contacting the mixture with a transition solvent whereby the casting solvent is removed from the mixture to form a second mixture containing the low k material and the transition solvent; contacting the second mixture with a supercritical fluid whereby the transition solvent is removed from the second mixture; and permitting the supercritical fluid to evaporate thereby forming the low k material layer.
Claims20
A method of forming a low k fluoropolymer layer on a semiconductor substrate, comprising:
- depositing a mixture comprising a low k fluoropolymer and a casting solvent on the semiconductor substrate, wherein the low k fluoropolymer comprises at least one of a fluorinated polyimide, a fluorinated benzocyclobutene, a copolymer of 2,2-bistrifluoromethyl 4,5-difluoro-1,3-dioxole, a perfluoroalkoxy resin, fluorinated ethylene propylene, fluoromethacrylate, parylene F, and amorphous polytetrafluoroethylene;
- optionally contacting the mixture with a transition solvent whereby the casting solvent is removed from the mixture to form a second mixture comprising the low k fluoropolymer and the transition solvent, wherein the transition solvent comprises at least one of a lower alkyl alcohol, a lower alkyl ketone, and a lower alkyl ester, wherein each alkyl group has 5 or less carbon atoms;
- contacting the mixture or the second mixture with a supercritical fluid whereby the casting solvent or the transition solvent is removed from the mixture or the second mixture;
- and
- permitting the supercritical fluid to evaporate thereby forming the low k fluoropolymer layer having a dielectric constant below about 3.
A method processing a low k fluoropolymer, comprising:
- depositing a mixture comprising the low k fluoropolymer and a casting solvent on a semiconductor substrate wherein the casting solvent comprises at least one of deionized water, a water based dispersion, a water-in-oil emulsion, an oil-in-water emulsion, benzenes, chlorobenzenes, anisole, cyclohexanone, a lower alkyl alcohol, a lower alkyl ketone, and a lower alkyl ester, wherein each alkyl group has 5 or less carbon atoms, and the low k fluoropolymer comprises at least one of a fluorinated polyimide, a fluorinated benzocyclobutene, a copolymer of 2,2-bistrifluoromethyl-4,5-difluoro-1,3-dioxole, a perfluoroalkoxy resin, fluorinated ethylene propylene, fluoromethacrylate, parylene F, and amorphous polytetrafluoroethylene;
- contacting the mixture with a transition solvent whereby the casting solvent is removed from the mixture to form a second mixture comprising the low k fluoropolymer and the transition solvent, wherein the transition solvent comprises at least one of a lower alkyl alcohol, a lower alkyl ketone, and a lower alkyl ester, wherein each alkyl group has 5 or less carbon atoms;
- contacting the second mixture with a supercritical fluid whereby the transition solvent is removed from the second mixture;
- and
- permitting the supercritical fluid to evaporate thereby forming a low k fluoropolymer layer having a dielectric constant below about 3.
A method of making a low k fluoropolymer dieletric layer, comprising:
- depositing a mixture comprising a low k fluoropolymer and a casting solvent on a semiconductor substrate, wherein the low k fluoropolymer comprises at least one of a fluorinated polyimide, a fluorinated benzocyclobutene, a copolymer of 2,2-bistrifluoromethyl-4,5-difluoro-1,3-dioxole, a perfluoroalkoxy resin, fluorinated ethylene propylene, fluoromethacrylate, parylene F, and amorphous polytetrafluoroethylene;
- contacting the mixture with an organic solvent whereby the casting solvent is removed from the mixture to form a second mixture comprising the low k fluoropolymer and the organic solvent, wherein the organic solvent comprises at least one of a ketone, an ester, an alcohol, an ether, and an aromatic hydrocarbon;
- contacting the second mixture with a supercritical fluid using spin coating whereby the organic solvent is removed from the second mixture, wherein the supercritical fluid comprises at least one of CO2, N2O, C2H6, CFH3, H2O, NH3, and CClF3 wherein the supercritical fluid has a critical temperature and pressure and is formed by providing a composition in a liquid phase;
- and
- permitting the supercritical fluid to evaporate by raising the pressure of the composition above the critical pressure, and raising the temperature above the critical temperature thereby forming the low k fluoropolymer dieletric layer having a dielectric constant below about 3.
Dependencies are inferred from the claim text.