Patents by Inventor Abaneshwar Prasad
Abaneshwar Prasad 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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Patent number: 7059936Abstract: The invention provides a polishing pad substrate comprising a copolymer, wherein the copolymer has at least one hydrophilic repeat unit and at least one hydrophobic repeat unit. The invention also provides a polishing pad substrate comprising a polymer, wherein the polymer is a modified polymer having at least one hydrophilic unit and at least one hydrophobic unit attached to the polymer chain. The invention further provides a method of polishing a workpiece comprising (i) providing a workpiece to be polished, (ii) contacting the workpiece with a chemical-mechanical polishing system comprising the polishing pad substrate of the invention, and (iii) abrading at least a portion of the surface of the workpiece with the polishing system to polish the workpiece.Type: GrantFiled: March 23, 2004Date of Patent: June 13, 2006Assignee: Cabot Microelectronics CorporationInventor: Abaneshwar Prasad
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Publication number: 20060052040Abstract: A method of manufacturing a chemical-mechanical polishing (CMP) pad comprises the steps of (a) forming a layer of a polymer resin liquid solution (i.e., a polymer resin dissolved in a solvent); (b) inducing a phase separation in the layer of polymer solution to produce an interpenetrating polymeric network comprising a continuous polymer-rich phase interspersed with a continuous polymer-depleted phase in which the polymer-depleted phase constitutes about 20 to about 90 percent of the combined volume of the phases; (c) solidifying the continuous polymer-rich phase to form a porous polymer sheet; (d) removing at least a portion of the polymer-depleted phase from the porous polymer sheet; and (e) forming a CMP pad therefrom.Type: ApplicationFiled: November 2, 2005Publication date: March 9, 2006Inventor: Abaneshwar Prasad
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Publication number: 20060046622Abstract: The invention provides a polishing pad for chemical-mechanical polishing comprising a polymeric material comprising two or more adjacent regions, wherein the regions have the same polymer formulation and the transition between the regions does not include a structurally distinct boundary. In a first embodiment, a first region and a second adjacent region have a first and second non-zero void volume, respectively, wherein the first void volume is less than the second void volume. In a second embodiment, a first non-porous region is adjacent to a second adjacent porous region, wherein the second region has an average pore size of about 50 ?m or less. In a third embodiment, at least two of an optically transmissive region, a first porous region, and an optional second porous region, are adjacent. The invention further provides methods of polishing a substrate comprising the use of the polishing pads and a method of producing the polishing pads.Type: ApplicationFiled: September 1, 2004Publication date: March 2, 2006Applicant: Cabot Microelectronics CorporationInventor: Abaneshwar Prasad
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Patent number: 6998166Abstract: The invention provides a polishing pad for chemical-mechanical polishing comprising a body, a polishing surface, and a plurality of elongated pores, wherein about 10% or more of the elongated pores have an aspect ratio of about 3:1 or greater and are substantially oriented in a direction that is coplanar with the polishing surface. The invention further provides a method of polishing a substrate.Type: GrantFiled: June 17, 2003Date of Patent: February 14, 2006Assignee: Cabot Microelectronics CorporationInventor: Abaneshwar Prasad
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Publication number: 20050277371Abstract: The invention is directed to a chemical-mechanical polishing pad substrate comprising a microporous closed-cell foam characterized by a narrow pore size distribution in the range of about 0.01 microns to about 10 microns. The polishing pad is produced by foaming a solid polymer sheet with a supercritical gas under an elevated temperature and pressure until the sheet is saturated with gas. The invention is further directed to a polishing pad comprising the polishing pad substrate, a method of polishing comprising the use of the polishing pad substrate, and a chemical-mechanical apparatus comprising the polishing pad substrate.Type: ApplicationFiled: June 22, 2005Publication date: December 15, 2005Inventor: Abaneshwar Prasad
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Publication number: 20050276967Abstract: A surface-textured polishing pad suitable for chemical-mechanical polishing comprises a porous polymeric foam having an average pore cell size in the range of about 60 ?m or less. At least about 75% of the pores in the foam have a pore cell size within about 30 ?m of the average pore cell size. The pad has at least one textured surface that includes divots having a depth in the range of about 25 ?m to about 1150 ?m, a width in the range of about 0.25 ?m to about 380 ?m, and a length-to-width aspect ratio of about 1 to about 1000. In addition, the at least one textured surface of the pad includes at least about 10 divots per square centimeter of surface area, and has an average surface roughness of at least about 5 ?m. Preferably, at least one textured surface has at least one pattern of spaced, parallel grooves imprinted thereon.Type: ApplicationFiled: August 19, 2005Publication date: December 15, 2005Inventor: Abaneshwar Prasad
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Patent number: 6960120Abstract: The invention is directed to chemical-mechanical polishing pads comprising a transparent window. In one embodiment, the transparent window comprises an inorganic material and an organic material, wherein the inorganic material comprises about 20 wt. % or more of the transparent window. In another embodiment, the transparent window comprises an inorganic material and an organic material, wherein the inorganic material is dispersed throughout the organic material and has a dimension of about 5 to 1000 nm, and wherein the transparent window has a total light transmittance of about 30% or more at at least one wavelength in the range of about 200 to 10,000 nm. In yet another embodiment, the transparent window comprises an inorganic/organic hybrid sol-gel material. In an additional embodiment, the transparent window comprises a polymer resin and a clarifying material, wherein the transparent window has a total light transmittance that is substantially higher than a window comprising only the polymeric resin.Type: GrantFiled: February 10, 2003Date of Patent: November 1, 2005Assignee: Cabot Microelectronics CorporationInventor: Abaneshwar Prasad
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Publication number: 20050215179Abstract: The invention provides a polishing pad substrate comprising a copolymer, wherein the copolymer has at least one hydrophilic repeat unit and at least one hydrophobic repeat unit. The invention also provides a polishing pad substrate comprising a polymer, wherein the polymer is a modified polymer having at least one hydrophilic unit and at least one hydrophobic unit attached to the polymer chain. The invention further provides a method of polishing a workpiece comprising (i) providing a workpiece to be polished, (ii) contacting the workpiece with a chemical-mechanical polishing system comprising the polishing pad substrate of the invention, and (iii) abrading at least a portion of the surface of the workpiece with the polishing system to polish the workpiece.Type: ApplicationFiled: March 23, 2004Publication date: September 29, 2005Applicant: Cabot Microelectronics CorporationInventor: Abaneshwar Prasad
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Publication number: 20050211376Abstract: The invention provides a chemical-mechanical polishing pad comprising a polishing layer comprising a hydrophobic region, a hydrophilic region, and an endpoint detection port. The hydrophobic region is substantially adjacent to the endpoint detection port. The hydrophobic region comprises a polymeric material having a surface energy of 34 mN/m or less and a polymeric material having a surface energy of more than 34 mN/m. The invention further provides a method of polishing a substrate comprising the use of the polishing pad.Type: ApplicationFiled: March 25, 2004Publication date: September 29, 2005Applicant: Cabot Microelectronics CorporationInventor: Abaneshwar Prasad
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Publication number: 20050215177Abstract: The invention provides a polishing pad comprising a polymeric material having pores and a component that is disposed within the pores, as well as a method of polishing a workpiece with the aforesaid polishing pad, and a method for producing the aforesaid polishing pad.Type: ApplicationFiled: March 23, 2004Publication date: September 29, 2005Applicant: Cabot Microelectronics CorporationInventor: Abaneshwar Prasad
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Publication number: 20050197050Abstract: The invention is directed to a multi-layer polishing pad for chemical-mechanical polishing comprising a porous polishing layer and a porous bottom layer, wherein the bottom layer is substantially coextensive with the polishing layer, the polishing layer being joined to the bottom layer without the use of an adhesive; the polishing layer having an average surface roughness, Ra, that is greater than the Ra of the bottom layer.Type: ApplicationFiled: April 25, 2005Publication date: September 8, 2005Inventors: Abaneshwar Prasad, Michael Lacy
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Patent number: 6935931Abstract: The invention provides polishing pads for chemical-mechanical polishing comprising a porous foam and a method for their production. In one embodiment, the porous foam has an average pore size of about 50 ?m or less, wherein about 75% or more of the pores have a pore size within about 20 ?m or less of the average pore size. In another embodiment, porous foam has an average pore size of about 20 ?m or less. In yet another embodiment, the porous foam has a multi-modal pore size distribution. The method of production comprises (a) combining a polymer resin with a supercritical gas to produce a single-phase solution and (b) forming a polishing pad from the single-phase solution, wherein the supercritical gas is generated by subjecting a gas to an elevated temperature and pressure.Type: GrantFiled: March 3, 2004Date of Patent: August 30, 2005Assignee: Cabot Microelectronics CorporationInventor: Abaneshwar Prasad
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Publication number: 20050153634Abstract: The invention is directed to a chemical-mechanical polishing pad comprising a porous polymeric material, wherein the porous polymeric material has a Poisson's ratio less than 0. The invention further provides a method of polishing a workpiece comprising (i) providing a workpiece to be polished, (ii) contacting the workpiece with a chemical-mechanical polishing system comprising the polishing pad of the invention, and (iii) abrading at least a portion of the surface of the workpiece with the polishing system to polish the workpiece.Type: ApplicationFiled: January 9, 2004Publication date: July 14, 2005Applicant: Cabot Microelectronics CorporationInventors: Abaneshwar Prasad, Ronald Myers
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Patent number: 6913517Abstract: The invention provides polishing pads for chemical-mechanical polishing comprising a porous foam and a method for their production. In one embodiment, the porous foam has an average pore size of about 50 ?m or less, wherein about 75% or more of the pores have a pore size within about 20 ?m or less of the average pore size. In another embodiment, porous foam has an average pore size of about 20 ?m or less. In yet another embodiment, the porous foam has a multi-modal pore size distribution. The method of production comprises (a) combining a polymer resin with a supercritical gas to produce a single-phase solution and (b) forming a polishing pad from the single-phase solution, wherein the supercritical gas is generated by subjecting a gas to an elevated temperature and pressure.Type: GrantFiled: October 28, 2002Date of Patent: July 5, 2005Assignee: Cabot Microelectronics CorporationInventor: Abaneshwar Prasad
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Patent number: 6899598Abstract: The invention provides polishing pads for chemical-mechanical polishing comprising a porous foam and a method for their production. In one embodiment, the porous foam has an average pore size of about 50 ?m or less, wherein about 75% or more of the pores have a pore size within about 20 ?m or less of the average pore size. In another embodiment, porous foam has an average pore size of about 20 ?m or less. In yet another embodiment, the porous foam has a multi-modal pore size distribution. The method of production comprises (a) combining a polymer resin with a supercritical gas to produce a single-phase solution and (b) forming a polishing pad from the single-phase solution, wherein the supercritical gas is generated by subjecting a gas to an elevated temperature and pressure.Type: GrantFiled: March 3, 2004Date of Patent: May 31, 2005Assignee: Cabot Microelectronics CorporationInventor: Abaneshwar Prasad
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Patent number: 6896593Abstract: The invention provides polishing pads for chemical-mechanical polishing comprising a porous foam and a method for their production. In one embodiment, the porous foam has an average pore size of about 50 ?m or less, wherein about 75% or more of the pores have a pore size within about 20 ?m of less of the average pore size. In another embodiment, porous foam has an average pore size of about 20 ?m or less. In yet another embodiment, the porous foam has a multi-modal pore size distribution. The method of production comprises (a) combining a polymer resin with a supercritical gas to produce a single-phase solution and (b) forming a polishing pad from the single-phase solution, wherein the supercritical gas is generated by subjecting a gas to an elevated temperature and pressure.Type: GrantFiled: March 3, 2004Date of Patent: May 24, 2005Assignee: Cabot Microelectronic CorporationInventor: Abaneshwar Prasad
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Publication number: 20050098540Abstract: The invention is directed to a polishing pad for use in chemical-mechanical polishing comprising a biodegradable polymer. The biodegradable polymer comprises a repeat unit selected from the group consisting of glycolic acid, lactic acid, hydroxyalkanoic acids, hydroxybutyric acid, hydroxyvaleric acid, caprolactone, p-dioxanone, trimethylene carbonate, butylene succinate, butylene adipate, monosaccharides, dicarboxylic acid anhydrides, enantiomers thereof, and combinations thereof. The invention is further directed to methods of its use.Type: ApplicationFiled: November 10, 2003Publication date: May 12, 2005Applicant: Cabot Microelectronics CorporationInventor: Abaneshwar Prasad
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Publication number: 20050101228Abstract: The invention is directed to a polishing pad for use in chemical-mechanical polishing comprising a biodegradable polymer. The biodegradable polymer comprises a repeat unit selected from the group consisting of glycolic acid, lactic acid, hydroxyalkanoic acids, hydroxybutyric acid, hydroxyvaleric acid, caprolactone, p-dioxanone, trimethylene carbonate, butylene succinate, butylene adipate, monosaccharides, dicarboxylic acid anhydrides, enantiomers thereof, and combinations thereof. The invention is further directed to methods of its use.Type: ApplicationFiled: November 10, 2003Publication date: May 12, 2005Applicant: Cabot Microelectronics CorporationInventor: Abaneshwar Prasad
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Patent number: 6884156Abstract: The invention is directed to a multi-layer polishing pad for chemical-mechanical polishing comprising a polishing layer and a bottom layer, wherein the polishing layer and bottom layer are joined together without the use of an adhesive. The invention is also directed to a polishing pad comprising an optically transmissive multi-layer polishing pad material, wherein the layers of the polishing pad material are joined together without the use of an adhesive.Type: GrantFiled: June 17, 2003Date of Patent: April 26, 2005Assignee: Cabot Microelectronics CorporationInventors: Abaneshwar Prasad, Roland K. Sevilla, Michael S. Lacy
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Publication number: 20040259484Abstract: The invention is directed to a multi-layer polishing pad for chemical-mechanical polishing comprising a polishing layer and a bottom layer, wherein the polishing layer and bottom layer are joined together without the use of an adhesive. The invention is also directed to a polishing pad comprising an optically transmissive multi-layer polishing pad material, wherein the layers of the polishing pad material are joined together without the use of an adhesive.Type: ApplicationFiled: June 17, 2003Publication date: December 23, 2004Applicant: Cabot Microelectronics CorporationInventors: Abaneshwar Prasad, Roland K. Sevilla, Michael S. Lacy