Patents Assigned to Semiquest Inc.
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Patent number: 8292692Abstract: A polishing pad includes a guide plate, a compressible foam under layer disposed adjacent to a lower surface of the guide plate, and a plurality of polishing elements that extend in a first direction substantially normal to a plane defined by the guide plate and through the guide plate. The pad further includes an optical path along the first direction and which is defined by an aperture in the compressible foam under layer and the guide plate. The optical path includes a transparent window that extends above an upper surface of the guide plate but below tips of the polishing elements, the upper surface of the guide plate being opposite the lower surface thereof. An optional slurry distribution layer may be disposed on the upper surface of the guide plate, in which case the polishing elements extend through the slurry distribution layer and the transparent window extends beyond a top surface thereof.Type: GrantFiled: November 11, 2009Date of Patent: October 23, 2012Assignee: Semiquest, Inc.Inventor: Rajeev Bajaj
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Patent number: 8177603Abstract: Polishing pads for use in chemical mechanical planarization (CMP) or polishing elements/surfaces of such pads are made from a combination of immiscible polymers, for example polyurethane and polyolefin. The polymers are selected on the basis of interfacial interaction, melt index and ratios of melt indices between the polymer phases—a matrix phase and a dispersed phase. By selecting the polymer system such that the two polymers are immiscible in one another and preferentially form separate domains, the dispersed phase can be removed when conditioning or polishing processes expose it. The melt index of individual polymers and the ratio of melt indices determines dispersability of a smaller phase into the matrix, hence the phase size.Type: GrantFiled: April 28, 2009Date of Patent: May 15, 2012Assignee: Semiquest, Inc.Inventor: Rajeev Bajaj
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Patent number: 8075745Abstract: A polishing pad includes a guide plate having a plurality of holes therein and being affixed to a compressible under-layer; and a plurality of conducting polishing elements each affixed to the compressible under-layer and passing through a sealed contact with a proton exchange membrane and corresponding hole in the guide plate so as to be maintained in a substantially vertical orientation with respect to the compressible under-layer but being translatable in a vertical direction with respect to the guide plate. The polishing pad may also include a slurry distribution material fastened to the guide plate by an adhesive. Pad wear sensors may also be provided in the polishing pad.Type: GrantFiled: October 5, 2005Date of Patent: December 13, 2011Assignee: Semiquest Inc.Inventor: Rajeev Bajaj
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Patent number: 8066555Abstract: A polishing pad includes polishing elements interdigitated with one another over a surface of the polishing pad. Each of the polishing elements is secured so as to restrict lateral movement thereof with respect to others of the polishing elements, but remains moveable in an axis normal to a polishing surface of the polishing elements. Different densities of the polishing elements may be positioned within different areas of the surface of the polishing pad.Type: GrantFiled: August 28, 2008Date of Patent: November 29, 2011Assignee: SemiQuest inc.Inventor: Rajeev Bajaj
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Patent number: 7846008Abstract: A polishing pad includes a guide plate, a porous slurry distribution layer and a flexible under-layer. Polishing elements are interdigitated with one another through the slurry distribution layer and the guide plate. The polishing elements may be affixed to the compressible under-layer and pass through corresponding holes in the guide plate so as to be maintained in a substantially vertical orientation with respect to the compressible under-layer but be translatable in a vertical direction with respect to the guide plate. Optionally, a membrane may be positioned between the guide plate and the slurry distribution layer. The polishing pad may also include wear sensors to assist in determinations of pad wear and end-of-life.Type: GrantFiled: April 6, 2007Date of Patent: December 7, 2010Assignee: Semiquest Inc.Inventor: Rajeev Bajaj
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Patent number: 7815778Abstract: A polishing pad includes at least one conductive polishing element supported by a compressible under layer having conductive patterning therein, the conductive patterning adapted to permit coupling of a potential to the conductive polishing element; a guide plate above the compressible under layer, the guide plate having a hole through which the polishing element passes and further having a cathodic element connected thereto; and a slurry distribution layer adhered to the guide plate opposite the compressible under layer. The polishing pad may further include a proton exchange membrane placed over the cathodic element. A semiconductor wafer having a metal film thereon may be polished using the polishing pad by placing the wafer in contact with the polishing element, applying anodic current to the polishing element and cathodic current to the cathodic element, and polishing with an anodic solution. For copper films, a sulfuric acid-copper sulfate solution may be used.Type: GrantFiled: November 21, 2006Date of Patent: October 19, 2010Assignee: Semiquest Inc.Inventor: Rajeev Bajaj
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Patent number: 7530880Abstract: A pad for CMP operations includes a guide plate having a plurality of holes therein and being affixed to a compressible under-layer; and a plurality of pressure-sensing and process monitoring polishing elements each affixed to the compressible under-layer and passing through a corresponding hole in the guide plate so as to be maintained in a substantially vertical orientation with respect to the compressible under-layer but being translatable in a vertical direction with respect to the guide plate.Type: GrantFiled: October 5, 2005Date of Patent: May 12, 2009Assignee: Semiquest Inc.Inventors: Rajeev Bajaj, Natraj Narayanswami, Bang C. Nguyen