Patents by Inventor Randhir P. S. Thakur

Randhir P. S. Thakur 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: 6403923
    Abstract: A system and process is disclosed for rapidly heating semiconductor wafers coated with a highly reflective material on either the whole wafer or in a patterned area. The wafers are heated in a thermal processing chamber by a plurality of lamps. In order for the wafer coated with the highly reflective material to more rapidly increase in temperature with lower power intensity, a shield member is placed in between the wafer and the plurality of lamps. The shield member is made from a high emissivity material, such as ceramic, that increases in temperature when exposed to light energy. Once heated, the shield member then in turn heats the semiconductor wafer with higher uniformity. In one embodiment, the shield member can also be used to determine the temperature of the wafer as it is heated.
    Type: Grant
    Filed: August 25, 2000
    Date of Patent: June 11, 2002
    Assignee: Mattson Technology, Inc.
    Inventors: Sing Pin Tay, Yao Zhi Hu, Randhir P. S. Thakur, Arnon Gat
  • Publication number: 20020067489
    Abstract: Disclosed is a process for analyzing the surface characteristics of opaque materials. The method comprises in one embodiment the use of a UV reflectometer to build a calibration matrix of data from a set of control samples and correlating a desired surface characteristic such as roughness or surface area to the set of reflectances of the control samples. The UV reflectometer is then used to measure the reflectances of a test sample of unknown surface characteristics. Reflectances are taken at a variety of angles of reflection for a variety of wavelengths, preferably between about 250 nanometers to about 400 nanometers. These reflectances are then compared against the reflectances of the calibration matrix in order to correlate the closest data in the calibration matrix. By so doing, a variety of information is thereby concluded, due to the broad spectrum of wavelengths and angles of reflection used.
    Type: Application
    Filed: October 29, 2001
    Publication date: June 6, 2002
    Applicant: Micron Technology, Inc.
    Inventors: Randhir P.S. Thakur, Michael Nuttall, J. Brett Rolfson, Robert James Burke
  • Patent number: 6400552
    Abstract: Capacitors and methods of forming capacitors are disclosed. In one implementation, a capacitor includes a capacitor dielectric layer including Ta2O5 formed over a first capacitor electrode. A second capacitor electrode is formed over the Ta2O5 capacitor dielectric layer. Preferably, at least a portion of the second capacitor electrode is formed over and in contact with the Ta2O5 in an oxygen containing environment at a temperature of at least about 175° C. Chemical vapor deposition is one example forming method. The preferred second capacitor electrode includes a conductive metal oxide. A more preferred second capacitor electrode includes a conductive silicon including layer, over a conductive titanium including layer, over a conductive metal oxide layer. A preferred first capacitor electrode includes a conductively doped Si—Ge alloy. Preferably, a Si3N4 layer is formed over the first capacitor electrode. DRAM cells and methods of forming DRAM cells are disclosed.
    Type: Grant
    Filed: April 30, 2001
    Date of Patent: June 4, 2002
    Assignee: Micron Technology, Inc.
    Inventors: Husam N. Al-Shareef, Scott Jeffrey DeBoer, F. Daniel Gealy, Randhir P. S. Thakur
  • Patent number: 6392284
    Abstract: A semiconductor structure includes a dielectric layer having first and second opposing sides. A conductive layer is adjacent to the first side of the dielectric layer and is coupled to a first terminal, and a conductive barrier layer is adjacent to the second side of the dielectric layer and is coupled to a second terminal. The conductive barrier layer may be formed from tungsten nitride, tungsten silicon nitride, titanium silicon nitride or other barrier materials.
    Type: Grant
    Filed: July 15, 1999
    Date of Patent: May 21, 2002
    Assignee: Micron Technology, Inc.
    Inventors: Randhir P. S. Thakur, Garry A. Mercaldi, Michael Nuttall
  • Patent number: 6383875
    Abstract: A first electrode and a doped oxide layer laterally proximate thereof are provided over a substrate. A silicon nitride layer is formed over both the doped oxide layer and the first electrode to a thickness of no greater than 80 Angstroms over at least the first electrode by low pressure chemical vapor deposition at a pressure of at least 1 Torr, a temperature of less than 700° C. and using feed gases comprising a silicon hydride and ammonia. The substrate with silicon nitride layer is exposed to oxidizing conditions comprising at least 700° C. to form a silicon dioxide layer over the silicon nitride layer, with the thickness of silicon nitride over the doped oxide layer being sufficient to shield oxidizable substrate material beneath the doped oxide layer from oxidizing during the exposing. A second electrode is formed over the silicon dioxide layer and the first electrode. In another implementation, a layer comprising undoped oxide is formed over a doped oxide layer.
    Type: Grant
    Filed: May 9, 2001
    Date of Patent: May 7, 2002
    Assignee: Micron Technology, Inc.
    Inventor: Randhir P. S. Thakur
  • Patent number: 6380103
    Abstract: At least both a rapid thermal etch step and a rapid thermal oxidation step are performed on a semiconductor substrate in situ in a rapid thermal processor. A method including an oxidation step followed by an etch step may be used to remove contamination and damage from a substrate. A method including a first etch step followed by an oxidation step and a second etch step may likewise be used to remove contamination and damage, and a final oxidation step may optionally be included to grow an oxide film. A method including an etch step followed by an oxidation step may also be used to grow an oxide film. Repeated alternate in situ oxidation and etch steps may be used until a desired removal of contamination or silicon damage is accomplished.
    Type: Grant
    Filed: February 26, 2001
    Date of Patent: April 30, 2002
    Assignee: Micron Technology, Inc.
    Inventors: Fernando Gonzalez, Randhir P. S. Thakur
  • Publication number: 20020045342
    Abstract: Methods and apparatus for forming word line stacks comprise one, or a combination of the following: a silicon diffusion barrier layer, doped with oxygen or nitrogen, coupled between a bottom silicon layer and a conductor layer; an amorphous silicon diffusion barrier coupled between a polysilicon layer and a conductor layer; a thin nitride layer coupled between a bottom silicon layer and a titanium silicide conductor layer, and a bottom silicon layer coupled to a conductor layer, which comprises C54-titanium silicide. Word line stacks formed by the methods of the invention are used in sub-0.25 micron line width applications and have a lower resistivity and improved thermal stability.
    Type: Application
    Filed: December 6, 1999
    Publication date: April 18, 2002
    Inventors: YONGJUN HU, PAI-HUNG PAN, ER-XUAN PING, RANDHIR P.S. THAKUR, SCOTT DE BOER
  • Publication number: 20020045314
    Abstract: A method of forming a corrugated capacitor on a semiconductor component. The method of forming the corrugated capacitor comprises a series of depositing alternating layers of doped silicon glass having different etch rates on a semiconductor component, covering the alternating layers with an etch-resistant material, and etching the alternating layers, thereby forming a capacitor structure having corrugated sides.
    Type: Application
    Filed: December 7, 2001
    Publication date: April 18, 2002
    Inventors: Randhir P.S. Thakur, Gordon Haller, Kirk D. Prall
  • Patent number: 6368887
    Abstract: A method of monitoring a process of manufacturing a semiconductor wafer including an area of hemispherical grain polysilicon, the method comprising providing a probe including a liquid conductor; and performing a capacitance-voltage measurement with the probe, using a quasi-static measurement method, to determine capacitance-voltage characteristics at the area of hemispherical grain polysilicon.
    Type: Grant
    Filed: May 22, 2000
    Date of Patent: April 9, 2002
    Assignee: Micron Technology, Inc.
    Inventors: Tyler A. Lowrey, Klaus F. Schuegraf, Randhir P. S. Thakur
  • Patent number: 6362086
    Abstract: A conductive structure for use in a semiconductor device includes a multilayer structure. A first layer includes a material containing silicon, e.g., polysilicon and silicon germanide. A barrier layer is formed over the first layer, with the barrier layer including metal silicide or metal silicide nitride. A top conductive layer is formed over the barrier layer. The top conductive layer can include metal or metal suicide. Selective oxidation can be performed to reduce the amount of oxidation of selected materials in a structure containing multiple layers, such as the multilayer conductive structure. The selective oxidation is performed in a single-wafer rapid thermal processing system, in which a selected ambient, including hydrogen, is used to ensure low oxidation of a selected material, such as tungsten or a metal nitride.
    Type: Grant
    Filed: September 15, 1999
    Date of Patent: March 26, 2002
    Assignee: Micron Technology, Inc.
    Inventors: Ronald A. Weimer, Yongjun Jeff Hu, Pai Hung Pan, Deepa Ratakonda, James Beck, Randhir P. S. Thakur
  • Patent number: 6359263
    Abstract: A system and process is disclosed for rapidly heating semiconductor wafers coated with a highly reflective material on either the whole wafer or in a patterned area. The wafers are heated in a thermal processing chamber by a plurality of lamps. In order for the wafer coated with the highly reflective material to more rapidly increase in temperature with lower power intensity, a shield member is placed in between the wafer and the plurality of lamps. The shield member is made from a high emissivity material, such as ceramic, that increases in temperature when exposed to light energy. Once heated, the shield member then in turn heats the semiconductor wafer with higher uniformity. In one embodiment, the shield member can also be used to determine the temperature of the wafer as it is heated.
    Type: Grant
    Filed: September 3, 1999
    Date of Patent: March 19, 2002
    Assignee: Steag RTP Systems, Inc.
    Inventors: Sing Pin Tay, Yao Zhi Hu, Randhir P. S. Thakur, Arnon Gat
  • Publication number: 20020025650
    Abstract: Structures and methods for making a semiconductor structure are discussed. The semiconductor structure includes a rough surface having protrusions formed from an undoped silicon film. If the semiconductor structure is a capacitor, the protrusions help to increase the capacitance of the capacitor. The semiconductor structure also includes a relatively smooth surface abutting the rough surface, wherein the relatively smooth surface is formed from a polycrystalline material.
    Type: Application
    Filed: September 26, 2001
    Publication date: February 28, 2002
    Inventors: Randhir P.S. Thakur, Garry A. Mercaldi, Michael Nuttall, Shenlin Chen, Er-Xuan Ping
  • Publication number: 20020022320
    Abstract: Capacitor constructions and methods of forming the same are described. In one implementation, a capacitor container is formed over a substrate and includes an internal surface and an external surface. At least some of the external surface is provided to be rougher than at least some of the internal container surface. A capacitor dielectric layer and an outer capacitor plate layer are formed over at least portions of the internal and the external surfaces of the capacitor container. In another implementation, a layer comprising roughened polysilicon is formed over at least some of the external container surface but not over any of the internal container surface. In a preferred aspect, the roughened external surface or roughened polysilicon comprises hemispherical grain polysilicon.
    Type: Application
    Filed: March 29, 2001
    Publication date: February 21, 2002
    Inventors: Scott J. DeBoer, Klaus F. Schuegraf, Randhir P.S. Thakur
  • Patent number: 6346455
    Abstract: A method of forming a corrugated capacitor on a semiconductor component. The method of forming the corrugated capacitor comprising a series of depositing alternating layers of doped silicon glass having different etch rates on a semiconductor component, covering the alternating layers with an etch resistant material, and etching the alternating layers thereby forming a capacitor structure having corrugated sides.
    Type: Grant
    Filed: August 31, 2000
    Date of Patent: February 12, 2002
    Assignee: Micron Technology, Inc.
    Inventors: Randhir P. S. Thakur, Gordon Haller, Kirk D. Prall
  • Publication number: 20020008292
    Abstract: Methods and apparatus for forming word line stacks comprise forming a thin nitride layer coupled between a bottom silicon layer and a conductor layer. In a further embodiment, a diffusion barrier layer is coupled between the thin nitride layer and the bottom silicon layer. The thin nitride layer is formed by annealing a silicon oxide film in a nitrogen-containing ambient.
    Type: Application
    Filed: August 11, 1998
    Publication date: January 24, 2002
    Inventors: YONGIUN HU, RANDHIR P S THAKUR, SCOTT DEBOER
  • Publication number: 20020006722
    Abstract: An embodiment of the present invention teaches a method used in a semiconductor fabrication process to form a memory cell in a semiconductor device comprising the steps of: subjecting a layered structure comprising a silicon gate insulating layer, a conductively doped polysilicon gate layer and a refractory metal silicide gate film to a thermal processing step; forming a sheet resistance capping layer directly on the refractory metal silicide film during at least a period of time of the thermal processing step, the sheet resistance capping layer forming a substantially uniform surface on the refractory metal silicide film; patterning and etching the layered structure to form the transistor gate; forming source and drain regions aligned to apposing sides of the transistor gate and formed into an underlying silicon substrate; and forming a storage capacitor (such as a stacked capacitor or a container cell) connecting to one of the source and drain regions.
    Type: Application
    Filed: September 7, 2001
    Publication date: January 17, 2002
    Inventor: Randhir P.S. Thakur
  • Publication number: 20020003622
    Abstract: Disclosed is a process for analyzing the surface characteristics of opaque materials. The method comprises in one embodiment the use of a UV reflectometer to build a calibration matrix of data from a set of control samples and correlating a desired surface characteristic such as roughness or surface area to the set of reflectances of the control samples. The UV reflectometer is then used to measure the reflectances of a test sample of unknown surface characteristics. Reflectances are taken at a variety of angles of reflection for a variety of wavelengths, preferably between about 250 nanometers to about 400 nanometers. These reflectances are then compared against the reflectances of the calibration matrix in order to correlate the closest data in the calibration matrix. By so doing, a variety of information is thereby concluded, due to the broad spectrum of wavelengths and angles of reflection used.
    Type: Application
    Filed: August 10, 2001
    Publication date: January 10, 2002
    Inventors: Randhir P.S. Thakur, Michael Nuttall, J. Brett Rolfson, Robert James Burke
  • Patent number: 6337243
    Abstract: A semiconductor processing method of providing a hemispherical grain polysilicon layer atop a substrate includes, a) providing a substantially amorphous layer of silicon over a substrate at a selected temperature; b) raising the temperature of the substantially amorphous silicon layer to a higher dielectric layer deposition temperature, the temperature raising being effective to transform the amorphous silicon layer into hemispherical grain polysilicon; and c) depositing a dielectric layer over the silicon layer at the higher dielectric deposition temperature. Transformation to hemispherical grain might occur during the temperature rise to the higher dielectric layer deposition temperature, after the higher dielectric layer deposition temperature has been achieved but before dielectric layer deposition, or after the higher dielectric layer deposition temperature has been achieved and during dielectric layer deposition.
    Type: Grant
    Filed: January 25, 2001
    Date of Patent: January 8, 2002
    Assignee: Micron Technology, Inc.
    Inventors: Er-Xang Ping, Randhir P. S. Thakur
  • Patent number: 6333225
    Abstract: In one aspect, the invention includes a method of forming circuitry comprising: a) forming a capacitor electrode over one region of a substrate: b) forming a capacitor dielectric layer proximate the electrode; c) forming a conductive diffusion barrier layer, the conductive diffusion barrier layer being between the electrode and the capacitor dielectric layer; d) forming a conductive plug over another region of the substrate, the conductive plug comprising a same material as the conductive diffusion barrier layer; and e) at least a portion of the conductive plug being formed simultaneously with the conductive diffusion barrier layer. In another aspect, the invention includes an integrated circuit comprising a capacitor and a conductive plug, the conductive plug and capacitor comprising a first common and continuous layer.
    Type: Grant
    Filed: August 20, 1999
    Date of Patent: December 25, 2001
    Assignee: Micron Technology, Inc.
    Inventors: Klaus Florian Schuegraf, Randhir P. S. Thakur
  • Patent number: 6333243
    Abstract: A method for forming field oxide isolation regions using oxygen implantation is described. An oxidation resistant layer such as silicon nitride is formed on a silicon substrate, and acts as an oxidation mask. An opening is then formed in the nitride layer, where field oxide is desired. In one embodiment of the invention, oxygen is implanted into this opening, followed by thermal oxidation. In a second embodiment of the invention, the opening is thermally oxidized, followed by a deep oxygen implant and anneal. Encroachment of the field oxide under the nitride layer is decreased, resulting in a minimum “birds' beak” length.
    Type: Grant
    Filed: February 17, 2000
    Date of Patent: December 25, 2001
    Assignee: Micron Technology, Inc.
    Inventors: Randhir P. S. Thakur, Michael Nuttall, Pai-Hung Pan