Patents by Inventor Freidoon Mehrad

Freidoon Mehrad 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: 7078347
    Abstract: A gate structure (30) is formed over a semiconductor (10). Sidewall structures (200) of a first width W1 are formed adjacent to the gate structure (30) and source and drain regions (90) are formed in the semiconductor (10). An etch process is performed to reduce the width of the sidewall structure to W2 and silicide regions (110) are then formed adjacent to the sidewall structures (205).
    Type: Grant
    Filed: March 6, 2003
    Date of Patent: July 18, 2006
    Assignee: Texas Instruments Incorporated
    Inventors: Freidoon Mehrad, Scott F. Johnson, Reji K. Koshy
  • Patent number: 7045410
    Abstract: A method (200) of forming an isolation structure is disclosed, and includes forming a patterned isolation hard mask layer (206, 212) having an isolation opening associated therewith over a semiconductor body. An implant into the isolation opening is then performed (214), followed by forming an isolation trench (216) in the semiconductor body associated with the isolation opening. The isolation trench is then filled with a dielectric material (218).
    Type: Grant
    Filed: July 27, 2004
    Date of Patent: May 16, 2006
    Assignee: Texas Instruments Incorporated
    Inventors: Freidoon Mehrad, Amitava Chatterjee
  • Publication number: 20060065946
    Abstract: The present invention provides a multi-doped semiconductor e-fuse for use in an integrated circuit and a method of manufacture therefore. In one aspect, the semiconductor e-fuse 200 includes a semiconductor body 205 having a neck region 220 interposed a first portion 210 of the semiconductor body 205 and a second portion 215 of the semiconductor body 205. The semiconductor body 205 is doped with opposite type dopants, and a conductive layer 230 is located over and extends across the neck region 220 to electrically connect the first portion 210 with the second portion 215.
    Type: Application
    Filed: September 30, 2004
    Publication date: March 30, 2006
    Inventors: Freidoon Mehrad, Richard Rouse, Robert Churchill
  • Publication number: 20060057853
    Abstract: An embodiment of the invention is a method for improving the uniformity of silicide 190 in semiconductor wafers 10. The method may include etching source/drain sidewall spacers 150, performing an oxidation of semiconductor wafer 10, and then performing a wet clean of semiconductor wafer 10.
    Type: Application
    Filed: September 15, 2004
    Publication date: March 16, 2006
    Inventors: Manoj Mehrotra, Freidoon Mehrad, F. Johnson
  • Publication number: 20060024911
    Abstract: A method (200) of forming an isolation structure is disclosed, and includes forming a patterned isolation hard mask layer (206, 212) having an isolation opening associated therewith over a semiconductor body. An implant into the isolation opening is then performed (214), followed by forming an isolation trench (216) in the semiconductor body associated with the isolation opening. The isolation trench is then filled with a dielectric material (218).
    Type: Application
    Filed: July 27, 2004
    Publication date: February 2, 2006
    Inventors: Freidoon Mehrad, Amitava Chatterjee
  • Publication number: 20060014393
    Abstract: The present invention substantially removes dry etch residue from a dry plasma etch process 110 prior to depositing a cobalt layer 124 on silicon substrate and/or polysilicon material. Subsequently, one or more annealing processes 128 are performed that cause the cobalt to react with the silicon thereby forming cobalt silicide regions. The lack of dry etch residue remaining between the deposited cobalt and the underlying silicon permits the cobalt silicide regions to be formed substantially uniform with a desired silicide sheet and contact resistance. The dry etch residue is substantially removed by performing a first cleaning operation 112 and then an extended cleaning operation 114 that includes a suitable cleaning solution. The first cleaning operation typically removes some, but not all of the dry etch residue. The extended cleaning operation 114 is performed at a higher temperature and/or for an extended duration and substantially removes dry etch residue remaining after the first cleaning operation 112.
    Type: Application
    Filed: July 19, 2004
    Publication date: January 19, 2006
    Inventors: Jiong-Ping Lu, Freidoon Mehrad, Lindsey Hall, Vivian Liu, Clint Montgomery, Scott Johnson
  • Publication number: 20050287751
    Abstract: The present invention pertains to a multi-layer sidewall process (100) that facilitates forming a transistor in a manner that allows adherence to certain design rules while concurrently mitigating adverse effects associated with forming areas of transistors close to one another. First sidewall spacers having first widths are formed (124) alongside a gate structure of a transistor to facilitate implanting source/drain dopants far enough away from the gate structure so that dopant atoms are unlikely to migrate into a channel area under the gate structure. Additionally, the process provides uniform layers for dopant atoms to pass through to mitigate variations in device characteristics across a wafer. The manner of forming the sidewall spacers also allows a salicide blocking process to be simplified. The first sidewall spacers are subsequently reduced (132) to establish second sidewall spacers having second widths which are smaller than the first widths.
    Type: Application
    Filed: June 25, 2004
    Publication date: December 29, 2005
    Inventors: Freidoon Mehrad, Vivian Liu, Amitava Chatterjee
  • Publication number: 20050247994
    Abstract: Disclosed is a shallow trench isolation (STI) structure and methods of manufacturing the same. The methods eliminate the requirement for design size adjustments (DSA) in manufacturing the STI structure. Further disclosed is an STI trench liner and methods for the formation thereof by growing a thin oxide layer on shallow isolation trench surfaces while preventing oxide formation on adjacent nitride surfaces, followed by the deposition of, and oxide growth upon, a polysilicon layer.
    Type: Application
    Filed: July 11, 2005
    Publication date: November 10, 2005
    Inventors: Freidoon Mehrad, Zhihao Chen, Shashank Ekbote, Brian Trentman
  • Publication number: 20050208732
    Abstract: A trench structure in a wafer of semiconductor material and the method of forming the trench structure are described. The trench structure is formed on a semiconductor wafer that has a top surface of slow oxidization rate—slower than that of other major crystallographic planes of the semiconductor material. The trench is etched into the semiconductor wafer. The trench has substantially vertical trench-sidewalls near the top surface, the vertical trench-sidewalls near the top surface containing crystallographic plane that oxidizes at a rate comparable to that of the top surface. An insulating layer is grown on the top surface and on the trench-sidewalls and on corners where sidewall surfaces approach the top surface, the insulating layer at the corners being substantially thicker than at the sidewall adjacent to the corners. The difference in the oxide thickness is due to the faster oxidizing planes exposed at the corners. Finally, the trench is filled with a dielectric material.
    Type: Application
    Filed: June 1, 2005
    Publication date: September 22, 2005
    Inventors: Zhihao Chen, Freidoon Mehrad, Brian Kirkpatrick, Jeff White, Edmund Russell, Jon Holt, Jason Mehigan
  • Patent number: 6930018
    Abstract: Disclosed is a shallow trench isolation (STI) structure and methods of manufacturing the same. The methods eliminate the requirement for design size adjustments (DSA) in manufacturing the STI structure. Further disclosed is an STI trench liner and methods for the formation thereof by growing a thin oxide layer on shallow isolation trench surfaces while preventing oxide formation on adjacent nitride surfaces, followed by the deposition of, and oxide growth upon, a polysilicon layer.
    Type: Grant
    Filed: July 16, 2002
    Date of Patent: August 16, 2005
    Assignee: Texas Instruments Incorporated
    Inventors: Freidoon Mehrad, Zhihao Chen, Shashank S. Ekbote, Brian Trentman
  • Patent number: 6930007
    Abstract: The present invention facilitates semiconductor device operation and fabrication by providing a cap-annealing process that improves channel electron mobility without substantially degrading PMOS transistor devices. The process uses an oxide/nitride composite-cap to alter the active dopant profile across the channel regions. During an annealing process, dopants migrate out of the Si/SiO2 in a channel region thereby altering the dopant profile of the channel region. This altered profile generally improves channel mobility thereby improving transistor performance and permitting smaller density designs.
    Type: Grant
    Filed: September 15, 2003
    Date of Patent: August 16, 2005
    Assignee: Texas Instruments Incorporated
    Inventors: Haowen Bu, Shashank Ekbote, Rajesh Khamankar, Shaoping Tang, Freidoon Mehrad
  • Publication number: 20050164431
    Abstract: The present invention facilitates semiconductor device operation and fabrication by providing a cap-annealing process that improves channel electron mobility without substantially degrading PMOS transistor devices. The process uses an oxide/nitride composite cap to alter the active dopant profile across the channel regions. During an annealing process, dopants migrate out of the Si/SiO2 in a channel region thereby altering the dopant profile of the channel region. This altered profile generally improves channel mobility thereby improving transistor performance and permitting smaller density designs.
    Type: Application
    Filed: March 4, 2005
    Publication date: July 28, 2005
    Inventors: Haowen Bu, Shashank Ekbote, Rajesh Khamankar, Shaoping Tang, Freidoon Mehrad
  • Patent number: 6917093
    Abstract: A trench structure in a wafer of semiconductor material and the method of forming the trench structure are described. The trench structure is formed on a semiconductor wafer that has a top surface of slow oxidization rate—slower than that of other major crystallographic planes of the semiconductor material. The trench is etched into the semiconductor wafer. The trench has substantially vertical trench-sidewalls near the top surface, the vertical trench-sidewalls near the top surface containing crystallographic plane that oxidizes at a rate comparable to that of the top surface. An insulating layer is grown on the top surface and on the trench-sidewalls and on corners where sidewall surfaces approach the top surface, the insulating layer at the corners being substantially thicker than at the sidewall adjacent to the corners. The difference in the oxide thickness is due to the faster oxidizing planes exposed at the corners. Finally, the trench is filled with a dielectric material.
    Type: Grant
    Filed: October 23, 2003
    Date of Patent: July 12, 2005
    Assignee: Texas Instruments Incorporated
    Inventors: Zhihao Chen, Freidoon Mehrad, Brian K. Kirkpatrick, Jeff A. White, Edmund G. Russell, Jon Holt, Jason D. Mehigan
  • Patent number: 6905943
    Abstract: In one embodiment, a method for forming a semiconductor structure in manufacturing a semiconductor device includes providing a pad layer on a surface of a substrate, providing a nitride layer on the pad layer, and providing a sacrificial oxide layer on the nitride layer. In a first etching step, at least the sacrificial oxide and nitride layers are etched to define opposing substantially vertical surfaces of at least the sacrificial oxide and nitride layers. In a second etching step, the nitride layer is etched such that the opposing substantially vertical surfaces of the nitride layer are recessed from the opposing substantially vertical surfaces of the sacrificial oxide layer, the sacrificial oxide layer substantially preventing the nitride layer from decreasing in thickness as a result of the etching of the nitride layer. In a third etching step, the substrate is etched to form a trench extending into the substrate for purposes of defining one or more isolation regions adjacent the trench.
    Type: Grant
    Filed: November 6, 2003
    Date of Patent: June 14, 2005
    Assignee: Texas Instruments Incorporated
    Inventors: Juanita DeLoach, Freidoon Mehrad, Brian M. Trentman, Troy A. Yocum
  • Patent number: 6897516
    Abstract: A method of forming a flash memory array structure includes forming a first dielectric layer outwardly from a semiconductor substrate, removing a portion of the first dielectric layer and the substrate to create a trench isolation region, forming a second dielectric layer in the trench isolation region, removing a portion of the second dielectric layer to create an exposed substrate region proximate a bottom of the trench isolation region, doping the exposed substrate region with an n-type dopant, and forming a silicide region in the exposed substrate region.
    Type: Grant
    Filed: April 10, 2003
    Date of Patent: May 24, 2005
    Assignee: Texas Instruments Incorporated
    Inventors: Freidoon Mehrad, Suresh Potla, Zhihao Chen
  • Publication number: 20050101101
    Abstract: In one embodiment, a method for forming a semiconductor structure in manufacturing a semiconductor device includes providing a pad layer on a surface of a substrate, providing a nitride layer on the pad layer, and providing a sacrificial oxide layer on the nitride layer. In a first etching step, at least the sacrificial oxide and nitride layers are etched to define opposing substantially vertical surfaces of at least the sacrificial oxide and nitride layers. In a second etching step, the nitride layer is etched such that the opposing substantially vertical surfaces of the nitride layer are recessed from the opposing substantially vertical surfaces of the sacrificial oxide layer, the sacrificial oxide layer substantially preventing the nitride layer from decreasing in thickness as a result of the etching of the nitride layer. In a third etching step, the substrate is etched to form a trench extending into the substrate for purposes of defining one or more isolation regions adjacent the trench.
    Type: Application
    Filed: November 6, 2003
    Publication date: May 12, 2005
    Inventors: Juanita DeLoach, Freidoon Mehrad, Brian Trentman, Troy Yocum
  • Publication number: 20050062127
    Abstract: A trench structure in a wafer of semiconductor material and the method of forming the trench structure are described. The trench structure is formed on a semiconductor wafer that has a top surface of slow oxidization rate—slower than that of other major crystallographic planes of the semiconductor material. The trench is etched into the semiconductor wafer. The trench has substantially vertical trench-sidewalls near the top surface, the vertical trench-sidewalls near the top surface containing crystallographic plane that oxidizes at a rate comparable to that of the top surface. An insulating layer is grown on the top surface and on the trench-sidewalls and on corners where sidewall surfaces approach the top surface, the insulating layer at the corners being substantially thicker than at the sidewall adjacent to the corners. The difference in the oxide thickness is due to the faster oxidizing planes exposed at the corners. Finally, the trench is filled with a dielectric material.
    Type: Application
    Filed: October 23, 2003
    Publication date: March 24, 2005
    Inventors: Zhihao Chen, Freidoon Mehrad, Brian Kirkpatrick, Jeff White, Edmund Russell, Jon Holt, Jason Mehigan
  • Publication number: 20050059228
    Abstract: The present invention facilitates semiconductor device operation and fabrication by providing a cap-annealing process that improves channel electron mobility without substantially degrading PMOS transistor devices. The process uses an oxide/nitride composite-cap to alter the active dopant profile across the channel regions. During an annealing process, dopants migrate out of the Si/SiO2 in a channel region thereby altering the dopant profile of the channel region. This altered profile generally improves channel mobility thereby improving transistor performance and permitting smaller density designs.
    Type: Application
    Filed: September 15, 2003
    Publication date: March 17, 2005
    Inventors: Haowen Bu, Shashank Ekbote, Rajesh Khamankar, Shaoping Tang, Freidoon Mehrad
  • Patent number: 6828213
    Abstract: A method of improving shallow trench isolation (STI) gap fill and moat nitride pull back is provided by after the steps of growing a pad oxide, depositing a nitride layer on the pad oxide and the steps of moat patterning, moat etching and moat clean, the steps of growing thermal oxide, deglazing a part of a part of the moat nitride; depositing a thin nitride liner, etching the nitride to form a thin side wall nitride in the STI trench; and performing an oxide Hydroflouric (HF) acid deglazing before STI liner oxidating and depositing oxide to fill the trench.
    Type: Grant
    Filed: February 28, 2003
    Date of Patent: December 7, 2004
    Assignee: Texas Instruments Incorporated
    Inventors: Freidoon Mehrad, Zhihao Chen, Majid M. Mansoori
  • Publication number: 20040238915
    Abstract: A method for isolating semiconductor devices includes forming a first oxide layer outwardly from a semiconductor substrate, forming a first nitride layer outwardly from the first oxide layer, removing a portion of the first nitride layer, a portion of the first oxide layer, and a portion of the substrate to form a trench isolation region, forming a second oxide layer in the trench isolation region, forming a spin-on-glass region in the trench isolation region, annealing the spin-on-glass region, removing a portion of the spin-on-glass region to expose a shallow trench isolation region, and forming a third oxide layer in the shallow trench isolation region.
    Type: Application
    Filed: April 5, 2004
    Publication date: December 2, 2004
    Inventors: Zhihao Chen, Douglas T. Grider, Freidoon Mehrad