Patents by Inventor Ravi Iyer

Ravi Iyer 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: 6506645
    Abstract: A capacitor in a semiconductor integrated circuit is fabricated having a fixed charge density introduced near an electrode/dielectric interface. The fixed charge density compensates for the effects of a depletion layer, which would otherwise lower the effective capacitance. By shifting the undesirable effect of the depletion capacitance outside of the operating voltage range, the capacitor is effectively converted to an accumulation mode. The fixed charge density is preferably introduced by a plasma nitridation process performed prior to formnation of the capacitor dielectric.
    Type: Grant
    Filed: October 15, 2001
    Date of Patent: January 14, 2003
    Assignee: Micron Technology, Inc.
    Inventors: Ravi Iyer, Luan Tran, Charles L. Turner
  • Publication number: 20030008491
    Abstract: In aspect, the invention includes a semiconductor processing method comprising: a) forming an electrically insulative layer over a substrate; b) forming an opening within the electrically insulative layer, the opening having a periphery defined at least in part by a bottom surface and a sidewall surface; c) forming a first layer comprising TiN within the opening, the first layer being over the bottom surface and along the sidewall surface; d) forming a second layer comprising elemental Ti over the electrically insulative layer but substantially not within the opening, the second layer having a thickness of less than 50 Å along the sidewall surface and over the bottom surface; and e) forming an aluminum-comprising layer within the opening and over the second layer.
    Type: Application
    Filed: August 27, 2002
    Publication date: January 9, 2003
    Inventors: Gurtej S. Sandhu, Ravi Iyer
  • Patent number: 6501179
    Abstract: The invention encompasses methods of forming insulating materials between conductive elements. In one aspect, the invention includes a method of forming a material adjacent a conductive electrical component comprising: a) partially vaporizing a mass to form a matrix adjacent the conductive electrical component, the matrix having at least one void within it. In another aspect, the invention includes a method of forming a material between a pair of conductive electrical components comprising the following steps: a) forming a pair of conductive electrical components within a mass and separated by an expanse of the mass; b) forming at least one support member within the expanse of the mass, the support member not comprising a conductive interconnect; and c) vaporizing the expanse of the mass to a degree effective to form at least one void between the support member and each of the pair of conductive electrical components.
    Type: Grant
    Filed: August 2, 2001
    Date of Patent: December 31, 2002
    Assignee: Micron Technology, Inc.
    Inventors: Werner Juengling, Kirk D. Prall, Ravi Iyer, Gurtej S. Sandhu, Guy Blalock
  • Patent number: 6498109
    Abstract: A process for plasma etching metal films comprising the steps of forming a noble gas plasma, then transporting the noble gas plasma to a mixing chamber. An organohalide is added to the noble gas plasma in the mixing chamber. The organohalide is selected to have a vapor pressure allowing the formation of activated complexes to etch the metal films and form organometallic compounds as the etch byproducts. The activated complexes thus formed are transported downstream to an etching chamber. In the etching chamber the selected substrate is exposed to the activated complexes, causing the substrate to be etched and organometallic compounds to be formed as byproducts from the reaction of the activated complexes and etching of the substrate. The organometallic byproducts can then be removed from the etch chamber.
    Type: Grant
    Filed: March 1, 2001
    Date of Patent: December 24, 2002
    Assignee: Micron Technology, Inc.
    Inventor: Ravi Iyer
  • Publication number: 20020190384
    Abstract: The fixed charge in a borophosphosilicate glass insulating film deposited on a semiconductor device is reduced by reacting an organic precursor such as TEOS with O3. When done at temperatures higher than approximately 480 degrees C., the carbon level in the resulting film appears to be reduced, resulting in a higher threshold voltage for field transistor devices.
    Type: Application
    Filed: August 26, 2002
    Publication date: December 19, 2002
    Applicant: Micron Technology, Inc.
    Inventors: Ravi Iyer, Randhir P. S. Thakur, Howard E. Rhodes
  • Patent number: 6495450
    Abstract: A method of forming an oxidation diffusion barrier stack for use in fabrication of integrated circuits includes forming an inorganic antireflective material layer on a semiconductor substrate assembly with an oxidation diffusion barrier layer then formed on the inorganic antireflective material layer. Another method of forming such a stack includes forming a pad oxide layer on the semiconductor substrate assembly with an inorganic antireflective material layer then formed on the pad oxide layer and an oxidation diffusion barrier layer formed on the antireflective material layer. The antireflective material layer may include a layer of material selected from the group of silicon nitride, silicon oxide, and silicon oxynitride and further may be a silicon-rich layer. The oxidation diffusion barrier stacks may be used for oxidation of field regions for isolation in an integration circuit. Further, the various oxidation diffusion barrier stacks are also described.
    Type: Grant
    Filed: July 21, 2000
    Date of Patent: December 17, 2002
    Assignee: Micron Technology, Inc.
    Inventors: Ravi Iyer, Steven M. McDonald, Thomas R. Glass, Zhiping Yin
  • Publication number: 20020182825
    Abstract: A method for depositing highly conformal silicate glass layers via chemical vapor deposition through the reaction of TEOS and O3 comprises placing an in-process semiconductor wafer having multiple surface constituents in a plasma-enhanced chemical vapor deposition chamber.
    Type: Application
    Filed: July 22, 2002
    Publication date: December 5, 2002
    Inventor: Ravi Iyer
  • Publication number: 20020171146
    Abstract: Various embodiments of the invention described herein reduce contact resistance to a silicon-containing material using a first refractory metal material overlying the silicon-containing material and a second refractory metal material overlying the first refractory metal material. Each refractory metal material is a conductive material containing a refractory metal and an impurity. The first refractory metal material is a metal-rich material, containing a level of its impurity at less than a stoichiometric level. The second refractory metal material has a lower affinity for the impurities than does the first refractory metal material. The second refractory metal material can thus serve as an impurity donor during an anneal or other exposure to heat.
    Type: Application
    Filed: May 16, 2001
    Publication date: November 21, 2002
    Applicant: Micron Technology, Inc.
    Inventors: Ravi Iyer, Yongjun Jeff Hu, Luan Tran, Brent Gilgen
  • Patent number: 6461950
    Abstract: In one aspect, the invention includes a semiconductor processing method comprising a) forming a metal silicide layer over a substrate; b) depositing a layer comprising silicon, nitrogen and oxygen over the metal silicide layer; and c) while the layer comprising silicon, nitrogen and oxygen is over the metal silicide layer, annealing the metal silicide layer.
    Type: Grant
    Filed: May 30, 2001
    Date of Patent: October 8, 2002
    Assignee: Micron Technology, Inc.
    Inventors: Zhiping Yin, Ravi Iyer, Thomas R. Glass, Richard Holscher, Ardavan Niroomand, Linda K. Somerville, Gurtej S. Sandhu
  • Patent number: 6462394
    Abstract: A method of fabricating an integrated circuit having reduced threshold voltage shift is provided. A nonconducting region is formed on the semiconductor substrate and active regions are formed on the semiconductor substrate. The active regions are separated by the nonconducting region. A barrier layer and a dielectric layer are deposited over the nonconducting region and over the active regions. Heat is applied to the integrated circuit causing the barrier layer to anneal.
    Type: Grant
    Filed: May 13, 1999
    Date of Patent: October 8, 2002
    Assignee: Micron Technology, Inc.
    Inventors: Randhir P. S. Thakur, Ravi Iyer, Howard Rhodes
  • Patent number: 6458721
    Abstract: A method for depositing highly conformal silicate glass layers via chemical vapor deposition through the reaction of TEOS and O3 comprises placing an in-process semiconductor wafer having multiple surface constituents in a plasma-enhanced chemical vapor deposition chamber. A “clean” silicate glass base layer substantially free of carbon particle impurities on an upper surface is formed in one of two ways. The first employs plasma-enhanced chemical vapor deposition using TEOS and diatomic oxygen gases as precursors to first deposit a “dirty” silicate glass base layer having carbon particle impurities imbedded on an upper surface thereof being transformed to a clean base layer by subjecting it to a plasma treatment, using a mixture of a diamagnetic oxygen-containing oxidant, such as ozone or hydrogen peroxide, and diatomic oxygen gas into the chamber and striking an RF plasma.
    Type: Grant
    Filed: August 23, 2001
    Date of Patent: October 1, 2002
    Assignee: Micron Technology, Inc.
    Inventor: Ravi Iyer
  • Patent number: 6455394
    Abstract: A method of forming isolation regions in a silicon substrate comprising the steps of forming a trench in the silicon substrate, filling the trench with a silanol polymer material then heating the silanol polymer material so that silicon dioxide is formed in the trench and thereby forms the isolation region. In the preferred embodiment, the silicon substrate is covered by a masking stack which is then etched to expose the underlying silicon substrate. The silicon substrate is then etched to form the trench and the silanol polymer material is deposited in the trench and fills the trench from the bottom up thereby avoiding divots and other defects. The silanol polymer grows faster on the silicon substrate than it does on the nitride. After the silanol polymer is reacted to form the silicon dioxide, CMP polishing is then used to remove the remaining masking stack and silicon dioxide above the surface of the silicon substrate.
    Type: Grant
    Filed: March 13, 1998
    Date of Patent: September 24, 2002
    Assignee: Micron Technology, Inc.
    Inventors: Ravi Iyer, Gurtej Sandhu, Pai Pan
  • Patent number: 6441466
    Abstract: The fixed charge in a borophosphosilicate glass insulating film deposited on a semiconductor device is reduced by reacting an organic precursor such as TEOS with O3. When done at temperatures higher than approximately 480 degrees C., the carbon level in the resulting film appears to be reduced, resulting in a higher threshold voltage for field transistor devices.
    Type: Grant
    Filed: September 2, 1998
    Date of Patent: August 27, 2002
    Assignee: Micron Technology, Inc.
    Inventors: Ravi Iyer, Randhir P. S. Thakur, Howard E. Rhodes
  • Patent number: 6432813
    Abstract: A semiconductor processing method of forming an electrically conductive interconnect line having an electrical conductive covering predominately coextensive therewith, includes, a) providing an conductive interconnect line over a first electrically insulating material, the line having a top and sidewalls; b) selectively depositing a second electrically insulating material layer over the interconnect line and the first insulating material in a manner which deposits a greater thickness of the second insulating material atop the interconnect line than a thickness of the second insulating material over the first insulating material; c) anisotropically etching the second insulating material layer inwardly to at least the first insulating material yet leaving second insulating material over the top and the side walls of the interconnect line; and d) providing an electrically conductive layer over the anisotropically etched second insulating layer to form a conductive layer (which is predominately coextensive with t
    Type: Grant
    Filed: August 5, 1999
    Date of Patent: August 13, 2002
    Assignee: Micron Technology, Inc.
    Inventors: Gurtej S. Sandhu, Ravi Iyer
  • Patent number: 6423631
    Abstract: A method of forming an oxidation diffusion barrier stack for use in fabrication of integrated circuits includes forming an inorganic antireflective material layer on a semiconductor substrate assembly with an oxidation diffusion barrier layer then formed on the inorganic antireflective material layer. Another method of forming such a stack includes forming a pad oxide layer on the semiconductor substrate assembly with an inorganic antireflective material layer then formed on the pad oxide layer and an oxidation diffusion barrier layer formed on the antireflective material layer. Another method of forming the stack includes forming a pad oxide layer on the semiconductor substrate assembly. A first oxidation diffusion barrier layer is then formed on the pad oxide layer, an inorganic antireflective material layer is formed on the first oxidation diffusion barrier layer, and a second oxidation diffusion barrier layer is formed on the inorganic antireflective material layer.
    Type: Grant
    Filed: July 25, 2000
    Date of Patent: July 23, 2002
    Assignee: Micron Technology, Inc.
    Inventors: Ravi Iyer, Steven M. McDonald, Thomas R. Glass, Zhiping Yin
  • Patent number: 6410984
    Abstract: A method of forming a local interconnect structure is provided. A first barrier layer comprising sputtered titanium nitride is formed over a topographical structure situated upon a field oxide region within a semiconductor substrate. A hard mask layer comprising tungsten silicide is formed over the first barrier layer. A photoresist layer is then formed over the hard mask layer. The hard mask layer is selectively removed from above an adjacent gate stack on the semiconductor substrate using an etch that is selective to the first barrier layer. The first barrier layer is selectively removed using an etch that is selective to the hard mask layer. A silica layer is formed over the hard mask layer. A recess is formed in the silica layer that is aligned with an active area within the semiconductor substrate. The recess is filled with an electrically conductive material.
    Type: Grant
    Filed: November 8, 1999
    Date of Patent: June 25, 2002
    Assignee: Micron Technology, Inc.
    Inventors: Jigish D. Trivedi, Ravi Iyer
  • Publication number: 20020068433
    Abstract: A method of forming a local interconnect structure is provided. A first barrier layer comprising sputtered titanium nitride is formed over a topographical structure situated upon a field oxide region within a semiconductor substrate. A hard mask layer comprising tungsten silicide is formed over the first barrier layer. A photoresist layer is then formed over the hard mask layer. The hard mask layer is selectively removed from above an adjacent gate stack on the semiconductor substrate using an etch that is selective to the first barrier layer. The first barrier layer is selectively removed using an etch that is selective to the hard mask layer. A silica layer is formed over the hard mask layer. A recess is formed in the silica layer that is aligned with an active area within the semiconductor substrate. The recess is filled with an electrically conductive material.
    Type: Application
    Filed: September 17, 2001
    Publication date: June 6, 2002
    Inventors: Jigish D. Trivedi, Ravi Iyer
  • Patent number: 6383723
    Abstract: A method for reducing defects in the profiles of chemically amplified photoresists used in deep ultraviolet (DUV) and laser lithography. Chemically amplified resists are typically highly sensitive to nitrogen-bearing surface contaminants, and photoresist layers formed on contaminated surfaces exhibit profile defects such as resist footing and T-topping. These defects are reduced by pretreating the surface of a semiconductor device or other structure with a cleansing etchant prior to the formation of the photoresist layer. The cleansing etchant is a solution of sulfuric acid and an oxidizing agent known as “piranha.
    Type: Grant
    Filed: August 28, 1998
    Date of Patent: May 7, 2002
    Assignee: Micron Technology, Inc.
    Inventors: Ravi Iyer, Ardavan Niroomand
  • Patent number: 6372669
    Abstract: The invention comprises methods of depositing silicon oxide material onto a substrate. In but one aspect of the invention, a method of depositing a silicon oxide containing layer on a substrate includes initially forming a layer comprising liquid silicon oxide precursor onto a substrate. After forming the layer, the layer is doped and transformed into a solid doped silicon oxide containing layer on the substrate. In a preferred implementation, the doping is by gas phase doping and the liquid precursor comprises Si(OH)4. In the preferred implementation, the transformation occurs by raising the temperature of the deposited liquid precursor to a first elevated temperature and polymerizing the deposited liquid precursor on the substrate. The temperature is continued to be raised to a second elevated temperature higher than the first elevated temperature and a solid doped silicon oxide containing layer is formed on the substrate.
    Type: Grant
    Filed: September 30, 1999
    Date of Patent: April 16, 2002
    Assignee: Micron Technology, Inc.
    Inventors: Gurtej S. Sandhu, Ravi Iyer
  • Publication number: 20020042179
    Abstract: The present invention is described in several embodiments depicting structures and methods to form these structures. A first embodiment is a structure having a silicon dioxide film bonded to a metal film comprising: a metal nitride film bonded to the metal film; and the silicon dioxide film bonded to the metal nitride film. A second embodiment is a structure having a silicon dioxide film bonded to a metal film comprising: a metal oxide film bonded to the metal film; and the silicon dioxide film bonded to the metal oxide film. A third embodiment is a structure having a silicon dioxide film bonded to a metal film comprising: a metal/oxide/nitride film bonded to the metal film; and the silicon dioxide film bonded to the metal/oxide/nitride film.
    Type: Application
    Filed: December 11, 2001
    Publication date: April 11, 2002
    Inventor: Ravi Iyer