Patents by Inventor Tushar P. Merchant

Tushar P. Merchant 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).

  • Patent number: 7528047
    Abstract: A method of forming a split gate memory device using a semiconductor layer includes patterning an insulating layer to leave a pillar thereof. A gate dielectric is formed over the semiconductor layer. A charge storage layer is formed over the gate dielectric and along first and second sides of the pillar. A gate material layer is formed over the gate dielectric and pillar. An etch is performed to leave a first portion of the gate material laterally adjacent to a first side of the pillar and over a first portion of the charge storage layer that is over the gate dielectric to function as a control gate of the memory device and a second portion of the gate material laterally adjacent to a second side of the pillar and over a second portion of the charge storage layer that is over the gate dielectric to function as a select gate.
    Type: Grant
    Filed: June 7, 2007
    Date of Patent: May 5, 2009
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Rajesh A. Rao, Tushar P. Merchant, Ramachandran Muralidhar, Lakshmanna Vishnubhotla
  • Publication number: 20090085024
    Abstract: A phase change memory cell has a first electrode, a plurality of pillars, and a second electrode. The plurality of pillars are electrically coupled with the first electrode. Each of the pillars comprises a phase change material portion and a heater material portion. The second electrode is electrically coupled to each of the pillars. In some examples, the pillars have a width less than 20 nanometers.
    Type: Application
    Filed: September 28, 2007
    Publication date: April 2, 2009
    Inventors: Ramachandran Muralidhar, Tushar P. Merchant, Rajesh A. Rao
  • Publication number: 20090085023
    Abstract: A phase change memory cell has a first electrode, a heater, a phase change material, and a second electrode. The heater is over the first electrode, and the heater comprises a pillar. The phase change material is around the heater. The second electrode is electrically coupled to the phase change material. In some embodiments, a method includes forming a electrode layer over a substrate, depositing a first layer, providing nanoclusters over the first layer, and etching the first layer. The first layer comprises one of a group consisting of a heater material and a phase change material. The first layer may be etched using the nanocluster defined pattern to form pillars from the first layer.
    Type: Application
    Filed: September 28, 2007
    Publication date: April 2, 2009
    Inventors: Ramachandran Muralidhar, Tushar P. Merchant, Rajesh A. Rao
  • Publication number: 20090061608
    Abstract: A method of depositing a silicon dioxide layer for a semiconductor device. The method includes depositing the silicon dioxide layer to have a silicon concentration of greater than 30 atomic percent and a nitrogen concentration of less than 5 atomic percent. The depositing includes flowing nitric oxide gas with a silicon precursor over a substrate. In one example, the silicon precursor and nitric oxide are flowed over a substrate with the substrate being at a temperature in a range of approximately 600 to approximately 900 degrees Celsius. In one example, the silicon dioxide layer is formed on a layer including charge storage memory material.
    Type: Application
    Filed: August 29, 2007
    Publication date: March 5, 2009
    Inventors: Tushar P. Merchant, Lakshmanna Vishnubhotla, Ramachandran Muralidhar, Rajesh A. Rao, Sriram Kalpat
  • Publication number: 20080303094
    Abstract: A method of forming a split gate memory device using a semiconductor layer includes patterning an insulating layer to leave a pillar thereof. A gate dielectric is formed over the semiconductor layer. A charge storage layer is formed over the gate dielectric and along first and second sides of the pillar. A gate material layer is formed over the gate dielectric and pillar. An etch is performed to leave a first portion of the gate material laterally adjacent to a first side of the pillar and over a first portion of the charge storage layer that is over the gate dielectric to function as a control gate of the memory device and a second portion of the gate material laterally adjacent to a second side of the pillar and over a second portion of the charge storage layer that is over the gate dielectric to function as a select gate.
    Type: Application
    Filed: June 7, 2007
    Publication date: December 11, 2008
    Inventors: Rajesh A. Rao, Tushar P. Merchant, Ramachandran Muralidhar, Lakshmanna Vishnubhotla
  • Publication number: 20080303067
    Abstract: A self-aligned split gate bitcell includes first and second regions of charge storage material separated by a gap devoid of charge storage material. Spacers are formed along sidewalls of sacrificial layer extending above and on opposite sides of the bitcell stack, wherein the spacers are separated from one another by at least a gap length. Etching the bitcell stack, selective to the spacers, forms a gap that splits the bitcell stack into first and second gates which together form the split gate bitcell stack. A storage portion of bitcell stack is also etched, wherein etching extends the gap and separates the corresponding layer into first and second separate regions, the extended gap being devoid of charge storage material. Dielectric material is deposited over the gap and etched back to expose a top surface of the sacrificial layer, which is thereafter removed to expose sidewalls of the split gate bitcell stack.
    Type: Application
    Filed: June 7, 2007
    Publication date: December 11, 2008
    Inventors: Rajesh A. Rao, Tushar P. Merchant, Ramachandran Muralidhar, Lakshmanna Vishnubhotla
  • Publication number: 20080242022
    Abstract: An electronic device can include a nonvolatile memory cell having DSEs within a dielectric layer. In one aspect, a process of forming the electronic device can include implanting and nucleating a first charge-storage material to form DSEs. The process can also include implanting a second charge-storage material and growing the DSEs such that the DSEs include the first and second charge-storage material. In another aspect, a process of forming the electronic device can include forming a semiconductor layer over a dielectric layer, implanting a charge-storage material, and annealing the dielectric layer. After annealing, substantially none of the charge-storage material remains within a denuded zone within the dielectric layer. In a third aspect, within a dielectric layer, a first set of DSEs can be spaced apart from a second set of DSEs, wherein substantially no DSEs lie between the first set of DSEs and the second set of DSEs.
    Type: Application
    Filed: March 30, 2007
    Publication date: October 2, 2008
    Applicant: FREESCALE SEMICONDUCTOR, INC.
    Inventors: Rajesh A. Rao, Tushar P. Merchant, Ramachandran Muralidhar, Gowrishankar Chindalore, David Sing, Jane Yater
  • Publication number: 20080182428
    Abstract: An electronic device can include a layer of discontinuous storage elements. A dielectric layer overlying the discontinuous storage elements can be substantially hydrogen-free. A process of forming the electronic device can include forming a layer including silicon over the discontinuous storage elements. In one embodiment, the process includes oxidizing at least substantially all of the layer. In another embodiment, the process includes forming the layer using a substantially hydrogen-free silicon precursor material and oxidizing at least substantially all of the layer.
    Type: Application
    Filed: January 26, 2007
    Publication date: July 31, 2008
    Applicant: Freescale Semiconductor, Inc.
    Inventors: Tushar P. Merchant, Chun-Li Liu, Ramachandran Muralidhar, Marius K. Orlowski, Rajesh A. Rao, Matthew Stoker
  • Publication number: 20070202645
    Abstract: An oxide layer formed by deposition is subject to a treatment process to repair bond defects of the oxide layer. In one embodiment, the layer is treated with nitric oxide. In one embodiment, a nitric oxide gas is flowed over the dielectric layer at an elevated temperature. In still another embodiment, the oxide layer is treated with fluorine. A layer is deposited over the oxide layer and a species containing fluorine is ion implanted into the layer. The wafer is heated where the species is driven to the oxide layer.
    Type: Application
    Filed: February 28, 2007
    Publication date: August 30, 2007
    Inventors: Tien Ying Luo, Lakshmanna Vishnubhotla, Tushar P. Merchant, Rajesh A. Rao, Ramachandran Muralidhar
  • Patent number: 6808986
    Abstract: Nanocrystals (22) are formed in a semiconductor, such as for example, in a memory having a floating gate. A dielectric (18) overlies a substrate (12) and is placed in a chemical vapor deposition chamber (34). A first precursor gas, such as disilane (36), is flowed into the chemical vapor deposition chamber during a first phase to nucleate the nanocrystals (22) on the dielectric with first predetermined processing conditions existing within the chemical vapor deposition chamber for a first time period. A second precursor gas, such as silane, is flowed into the chemical vapor deposition chamber during a second phase subsequent to the first phase to grow the nanocrystals under second predetermined processing conditions existing within the chemical vapor deposition chamber for a second time period.
    Type: Grant
    Filed: August 30, 2002
    Date of Patent: October 26, 2004
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Rajesh A. Rao, Ramachandran Muralidhar, Tushar P. Merchant
  • Patent number: 6784103
    Abstract: Nanocrystals (22) are formed in a semiconductor, such as for example, in a memory having a floating gate. A dielectric (18) overlies a substrate (12) and is placed in a chemical vapor deposition chamber (34). A first precursor gas, such as disilane (36), is flowed into the chemical vapor deposition chamber during a first phase to nucleate the nanocrystals (22) on the dielectric with first predetermined processing conditions existing within the chemical vapor deposition chamber for a first time period. A second precursor gas, such as silane, is flowed into the chemical vapor deposition chamber during a second phase subsequent to the first phase to grow the nanocrystals under second predetermined processing conditions existing within the chemical vapor deposition chamber for a second time period.
    Type: Grant
    Filed: May 21, 2003
    Date of Patent: August 31, 2004
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Rajesh A. Rao, Tushar P. Merchant, Ramachandran Muralidhar
  • Patent number: 6717226
    Abstract: A transistor device has a gate dielectric with at least two layers in which one is hafnium oxide and the other is a metal oxide different from hafnium oxide. Both the hafnium oxide and the metal oxide also have a high dielectric constant. The metal oxide provides an interface with the hafnium oxide that operates as a barrier for contaminant penetration. Of particular concern is boron penetration from a polysilicon gate through hafnium oxide to a semiconductor substrate. The hafnium oxide will often have grain boundaries in its crystalline structure that provide a path for boron atoms. The metal oxide has a different structure than that of the hafnium oxide so that those paths for boron in the hafnium oxide are blocked by the metal oxide. Thus, a high dielectric constant is provided while preventing boron penetration from the gate electrode to the substrate.
    Type: Grant
    Filed: March 15, 2002
    Date of Patent: April 6, 2004
    Assignee: Motorola, Inc.
    Inventors: Rama I. Hegde, Joe Mogab, Philip J. Tobin, Hsing H. Tseng, Chun-Li Liu, Leonard J. Borucki, Tushar P. Merchant, Christopher C. Hobbs, David C. Gilmer
  • Publication number: 20040043583
    Abstract: Nanocrystals (22) are formed in a semiconductor, such as for example, in a memory having a floating gate. A dielectric (18) overlies a substrate (12) and is placed in a chemical vapor deposition chamber (34). A first precursor gas, such as disilane (36), is flowed into the chemical vapor deposition chamber during a first phase to nucleate the nanocrystals (22) on the dielectric with first predetermined processing conditions existing within the chemical vapor deposition chamber for a first time period. A second precursor gas, such as silane, is flowed into the chemical vapor deposition chamber during a second phase subsequent to the first phase to grow the nanocrystals under second predetermined processing conditions existing within the chemical vapor deposition chamber for a second time period.
    Type: Application
    Filed: August 30, 2002
    Publication date: March 4, 2004
    Inventors: Rajesh A. Rao, Ramachandran Muralidhar, Tushar P. Merchant
  • Publication number: 20030176049
    Abstract: A transistor device has a gate dielectric with at least two layers in which one is hafnium oxide and the other is a metal oxide different from hafnium oxide. Both the hafnium oxide and the metal oxide also have a high dielectric constant. The metal oxide provides an interface with the hafnium oxide that operates as a barrier for contaminant penetration. Of particular concern is boron penetration from a polysilicon gate through hafnium oxide to a semiconductor substrate. The hafnium oxide will often have grain boundaries in its crystalline structure that provide a path for boron atoms. The metal oxide has a different structure than that of the hafnium oxide so that those paths for boron in the hafnium oxide are blocked by the metal oxide. Thus, a high dielectric constant is provided while preventing boron penetration from the gate electrode to the substrate.
    Type: Application
    Filed: March 15, 2002
    Publication date: September 18, 2003
    Inventors: Rama I. Hegde, Joe Mogab, Philip J. Tobin, Hsing H. Tseng, Chun-Li Liu, Leonard J. Borucki, Tushar P. Merchant, Christopher C. Hobbs, David C. Gilmer