Patents by Inventor Madhukar B. Rao
Madhukar B. Rao has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20230339986Abstract: A method for producing an alkenyl or alkynyl-containing organosilicon precursor composition, the method comprising the steps of distilling at least once a composition comprising an alkenyl or alkynyl-containing organosilicon compound having the formula RnSiR14-n wherein R is selected a linear or branched C2 to C6 alkenyl group, a linear or branched C2 to C6 alkynyl group; R1 is selected from hydrogen, a linear or branched C1 to C10 alkyl group, and a C3 to C10 cyclic alkyl group; and n is a number selected from 1 to 4, wherein a distilled alkenyl or alkynyl-containing organosilicon precursor composition is produced after distilling; and packaging the distilled alkenyl or alkynyl-containing organosilicon precursor composition in a container, wherein the container permits transmission into the container of no more than 10% of ultraviolet and visible light having a wavelength of between 290 nm to 450 nm.Type: ApplicationFiled: June 13, 2023Publication date: October 26, 2023Inventors: ROBERT G. RIDGEWAY, RAYMOND N. VRTIS, XINJIAN LEI, MADHUKAR B. RAO, STEVEN GERARD MAYORGA, NEILL OSTERWALDER, MANCHAO XIAO, MEILIANG WANG
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Patent number: 11713328Abstract: A method for producing an alkenyl or alkynyl-containing organosilicon precursor composition, the method comprising the steps of distilling at least once a composition comprising an alkenyl or alkynyl-containing organosilicon compound having the formula RnSiR14?n wherein R is selected a linear or branched C2 to C6 alkenyl group, a linear or branched C2 to C6 alkynyl group; R1 is selected from hydrogen, a linear or branched C1 to C10 alkyl group, and a C3 to C10 cyclic alkyl group; and n is a number selected from 1 to 4, wherein a distilled alkenyl or alkynyl-containing organosilicon precursor composition is produced after distilling; and packaging the distilled alkenyl or alkynyl-containing organosilicon precursor composition in a container, wherein the container permits transmission into the container of no more than 10% of ultraviolet and visible light having a wavelength of between 290 nm to 450 nm.Type: GrantFiled: August 21, 2019Date of Patent: August 1, 2023Assignee: VERSUM MATERIALS US, LLCInventors: Robert G. Ridgeway, Raymond N. Vrtis, Xinjian Lei, Madhukar B. Rao, Steven Gerard Mayorga, Neil Osterwalder, Manchao Xiao, Meiliang Wang
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Publication number: 20230058258Abstract: An atomic layer deposition method for depositing a film into surface features of a substrate is disclosed. The method may include the step of placing the substrate having surface features into a reactor. An organic passivation agent may be introduced into the 5 reactor, which may react with a portion of exposed hydroxyl radicals within the surface features. Subsequently, unreacted organic passivation agent may be purged, and then a precursor may be introduced. The precursor may react with the remaining exposed hydroxyl radicals that did not interact with the organic passivation agent. Subsequently, the unreacted precursor may be purged, and an oxygen source or a nitrogen source may 10 be introduced into the reactor to form a film within the surface features.Type: ApplicationFiled: December 22, 2020Publication date: February 23, 2023Applicant: VERSUM MATERIALS US, LLCInventors: HARIPIN CHANDRA, XINJIAN LEI, DANIEL P. SPENCE, MANCHAO XIAO, RONALD MARTIN PEARLSTEIN, MATTHEW R. MACDONALD, MADHUKAR B. RAO
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Publication number: 20220037144Abstract: A composition for depositing a high quality silicon nitride is introduced into a reactor that contains a substrate, followed by introduction of a plasma that includes an ammonia source. The composition includes a silicon precursor compound having Formula as defined herein.Type: ApplicationFiled: September 24, 2019Publication date: February 3, 2022Applicant: VERSUM MATERIALS US, LLCInventors: MADHUKAR B RAO, XINJIAN LEI, MATTHEW R MACDONALD, MOO-SUNG KIM, SE-WON LEE
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Publication number: 20210363639Abstract: Atomic layer deposition (ALD) process formation of silicon oxide with temperature >600° C. is disclosed. Silicon precursors used have a formula of: I.R1R2mSi(NR3R4)n wherein R1, R2, and R3 are each independently selected from a linear or branched C1 to C10 alkyl group, and a C6 to C10 aryl group; R4 is selected from hydrogen, a linear or branched C1 to C10 alkyl group, and a C6 to C10 aryl group, a C3 to C10 alkylsilyl group; wherein R3 and R4 are linked to form a cyclic ring structure or R3 and R4 are not linked to forma cyclic ring structure; m is 0 to 2; n is 1 to 3; and m+n=3.Type: ApplicationFiled: October 3, 2019Publication date: November 25, 2021Applicant: VERSUM MATERIALS US, LLCInventors: MEILIANG WANG, XINJIAN LEI, MADHUKAR B. RAO
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Patent number: 10985013Abstract: Described herein is an apparatus comprising a plurality of silicon-containing layers wherein the silicon-containing layers are selected from a silicon oxide and a silicon nitride layer or film. Also described herein are methods for forming the apparatus to be used, for example, as 3D vertical NAND flash memory stacks. In one particular aspect or the apparatus, the silicon oxide layer comprises slightly compressive stress and good thermal stability. In this or other aspects of the apparatus, the silicon nitride layer comprises slightly tensile stress and less than 300 MPa stress change after up to about 800° C. thermal treatment. In this or other aspects of the apparatus, the silicon nitride layer etches much faster than the silicon oxide layer in hot H3PO4, showing good etch selectivity.Type: GrantFiled: June 4, 2019Date of Patent: April 20, 2021Assignee: Versum Materials US, LLCInventors: Jianheng Li, Robert G. Ridgeway, Xinjian Lei, Raymond N. Vrtis, Bing Han, Madhukar B. Rao
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Publication number: 20200062787Abstract: A method for producing an alkenyl or alkynyl-containing organosilicon precursor composition, the method comprising the steps of distilling at least once a composition comprising an alkenyl or alkynyl-containing organosilicon compound having the formula RnSiR14?n wherein R is selected a linear or branched C2 to C6 alkenyl group, a linear or branched C2 to C6 alkynyl group; R1 is selected from hydrogen, a linear or branched C1 to C10 alkyl group, and a C3 to C10 cyclic alkyl group; and n is a number selected from 1 to 4, wherein a distilled alkenyl or alkynyl-containing organosilicon precursor composition is produced after distilling; and packaging the distilled alkenyl or alkynyl-containing organosilicon precursor composition in a container, wherein the container permits transmission into the container of no more than 10% of ultraviolet and visible light having a wavelength of between 290 nm to 450 nm.Type: ApplicationFiled: August 21, 2019Publication date: February 27, 2020Applicant: Versum Materials US, LLCInventors: Robert G. Ridgeway, Raymond N. Vrtis, Xinjian Lei, Madhukar B. Rao, Steven Gerard Mayorga, Neil Osterwalder, Manchao Xiao, Meiliang Wang
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Publication number: 20190376178Abstract: Described herein are compositions and methods using same for forming a silicon-containing film such as without limitation a silicon carbide, silicon nitride, silicon oxide, silicon oxynitride, a carbon-doped silicon nitride, a carbon-doped silicon oxide, or a carbon doped silicon oxynitride film on at least a surface of a substrate having a surface feature. In one aspect, the silicon-containing films are deposited using a compound comprising a carbon-carbon double or carbon-carbon triple bond. The plasma source employed comprises both a remote plasma source and an in-situ plasma source operating in combination.Type: ApplicationFiled: June 6, 2019Publication date: December 12, 2019Applicant: Versum Materials US, LLCInventors: Robert G. Ridgeway, Raymond N. Vrtis, Madhukar B. Rao
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Publication number: 20190318925Abstract: Described herein are precursors and methods for forming silicon-containing films. In one aspect, there is provided a precursor of Formula I: as described herein.Type: ApplicationFiled: April 3, 2019Publication date: October 17, 2019Applicant: Versum Materials US, LLCInventors: Xinjian Lei, Meiliang Wang, Madhukar B. Rao
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Patent number: 5507860Abstract: Improved composite semipermeable membranes including microporous carbonaceous adsorptive material supported by a porous substrate for use in separating multicomponent gas mixtures in which certain components in the mixture adsorb within the pores of the adsorptive material and diffuse by surface flow through the membrane to yield a permeate stream enriched in these components. Methods for making the improved composite membranes are described including one or more oxidation steps which increase the membrane permeability and selectivity.Type: GrantFiled: April 12, 1994Date of Patent: April 16, 1996Assignee: Air Products and Chemicals, Inc.Inventors: Madhukar B. Rao, Shivaji Sircar, Timothy C. Golden
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Patent number: 5507856Abstract: A composite semipermeable membrane comprising microporous adsorbent material supported by a porous substrate is utilized to separate hydrogen-hydrocarbon mixtures and a sweep gas comprising some of the same hydrocarbons is passed across the low pressure side of the membrane to enhance hydrocarbon permeability. Methane is an effective sweep gas which promotes the permeation of heavier hydrocarbons even when methane is present in the membrane feed.Type: GrantFiled: September 8, 1994Date of Patent: April 16, 1996Assignee: Air Products and Chemicals, Inc.Inventors: Madhukar B. Rao, Shivaji Sircar
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Patent number: 5447559Abstract: A composite semipermeable membrane comprising microporous adsorbent material supported by a porous substrate is operated in series with a pressure swing adsorption (PSA) system and the PSA reject gas is used as a sweep gas to improve membrane performance. The integrated membrane-PSA system is particularly useful for recovering high-purity hydrogen from a mixture of hydrogen and hydrocarbons, and is well-suited for integration with a steam-methane reformer.Type: GrantFiled: August 10, 1994Date of Patent: September 5, 1995Assignee: Air Products and Chemicals, Inc.Inventors: Madhukar B. Rao, Shivaji Sircar, Joseph M. Abrardo, William F. Baade
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Patent number: 5435836Abstract: Recovery of hydrogen from hydrogen-containing gas mixtures by pressure swing adsorption is increased by utilizing an adsorbent membrane to concentrate hydrogen in the pressure swing adsorption reject gas and recycling the resulting hydrogen-enriched stream to the feed of the pressure swing adsorption system. Lower compression requirements are realized compared with the use of polymeric membranes for the same service because the hydrogen-enriched stream is recovered from the adsorbent membrane as nonpermeate at essentially the membrane feed pressure. Simultaneous permeation of carbon dioxide and methane occur in the adsorbent membrane, which can be operated at feed pressures as low as 5 psig when hydrogen is used as a sweep gas.Type: GrantFiled: December 23, 1993Date of Patent: July 25, 1995Assignee: Air Products and Chemicals, Inc.Inventors: Madhu Anand, Madhukar B. Rao, Shivaji Sircar
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Patent number: 5431864Abstract: Improved composite semipermeable membranes including microporous carbonaceous adsorptive material supported by a porous substrate for use in separating multicomponent gas mixtures in which certain components in the mixture adsorb within the pores of the adsorptive material and diffuse by surface flow through the membrane to yield a permeate stream enriched in these components. Methods for making the improved composite membranes are described including one or more oxidation steps which increase the membrane permeability and selectivity.Type: GrantFiled: April 18, 1994Date of Patent: July 11, 1995Assignee: Air Products and Chemicals, Inc.Inventors: Madhukar B. Rao, Shivaji Sircar, Timothy C. Golden
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Patent number: 5354547Abstract: A composite semipermeable membrane comprising microporous adsorbent material supported by a porous substrate is operated in series with a pressure swing adsorption (PSA) system and the PSA reject gas is used as a sweep gas to improve membrane performance. The integrated membrane-PSA system is particularly useful for recovering high-purity hydrogen from a mixture of hydrogen and hydrocarbons, and is well-suited for integration with a steam-methane reformer.Type: GrantFiled: August 3, 1992Date of Patent: October 11, 1994Assignee: Air Products and Chemicals, Inc.Inventors: Madhukar B. Rao, Shivaji Sircar, Joseph M. Abrardo, William F. Baade
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Patent number: 5332424Abstract: A method is disclosed for separating a multicomponent gas mixture comprising at least three components into three product streams by use of adsorbent membrane zones operating in series. Each product is enriched in a different component based upon the relative strength of adsorption of each component on the adsorbent material. A non-permeate primary component product is obtained by the selective adsorption and permeation through the adsorbent membranes of secondary components which are more strongly adsorbed than the primary components in the gas mixture. Two or more permeate streams enriched in the more strongly adsorbed components are withdrawn from the membrane zones as individual secondary products, each of which contains a different component distribution determined by the relative strength of adsorption of the secondary components on the adsorbent material.Type: GrantFiled: July 28, 1993Date of Patent: July 26, 1994Assignee: Air Products and Chemicals, Inc.Inventors: Madhukar B. Rao, Shivaji Sircar, Joseph M. Abrardo, William F. Baade
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Patent number: 5116510Abstract: A new thermal swing adsorption process for the separation of a bulk liquid mixture into its respective components wherein a novel rinse step is employed to achieve high product recovery with a low energy of separation. The invention is particularly useful for separating liquid mixtures containing azeotropes or close-boiling components which are difficult to separate using conventional techniques such as distillation or routine termal swing adsorption. A given example is the separation and recovery of methyl acetate from a bulk liquid mixture containing methyl acetate and water.Type: GrantFiled: May 6, 1991Date of Patent: May 26, 1992Assignee: Air Products and Chemicals, Inc.Inventors: Shivaji Sircar, Madhukar B. Rao
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Patent number: 5104425Abstract: Composite semipermeable membranes comprising porous adsorptive material supported by a porous substrate are disclosed for use in a process for the separation of multicomponent gas mixtures. In the process, one or more primary components adsorb within the pores of the adsorptive material and diffuse by surface flow through the membrane to yield a permeate stream enriched in one or more of the primary components. Methods for making the composite membranes are described.Type: GrantFiled: July 1, 1991Date of Patent: April 14, 1992Assignee: Air Products and Chemicals, Inc.Inventors: Madhukar B. Rao, Shivaji Sircar, Timothy C. Golden