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).

  • Publication number: 20010053057
    Abstract: Capacitors and methods of forming capacitors are disclosed. In one implementation, a capacitor comprises a capacitor dielectric layer comprising 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 comprises a conductive metal oxide. A more preferred second capacitor electrode comprises a conductive silicon comprising layer, over a conductive titanium comprising layer, over a conductive metal oxide layer. A preferred first capacitor electrode comprises 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: Application
    Filed: April 30, 2001
    Publication date: December 20, 2001
    Inventors: Husam N. Al-Shareef, Scott Jeffrey DeBoer, F. Daniel Gealy, Randhir P. S. Thakur
  • Patent number: 6326321
    Abstract: In one aspect, the invention includes a semiconductor fabrication process, comprising: a) providing a substrate; b) forming a layer of silicon nitride over the substrate, the layer having a thickness; and c) enriching a portion of the thickness of the silicon nitride layer with silicon, the portion comprising less than or equal to about 95% of the thickness of the layer of silicon nitride. In another aspect, the invention includes a semiconductor fabrication process, comprising: a) providing a substrate; b) forming a layer of silicon nitride over the substrate, the layer having a thickness; and c) increasing a refractive index of a first portion of the thickness of the silicon nitride layer relative to a refractive index of a second portion of the silicon nitride layer, the first portion comprising less than or equal to about 95% of the thickness of the silicon nitride layer.
    Type: Grant
    Filed: June 27, 2000
    Date of Patent: December 4, 2001
    Assignee: Micron Technology, Inc.
    Inventors: Scott Jeffrey DeBoer, John T. Moore, Mark Fischer, Randhir P. S. Thakur
  • Patent number: 6327040
    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 nanomneters. 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: Grant
    Filed: February 26, 2001
    Date of Patent: December 4, 2001
    Assignee: Micron Technology, Inc.
    Inventors: Randhir P. S. Thakur, Michael Nuttall, J. Brett Rolfson, Robert James Burke
  • Patent number: 6325017
    Abstract: An apparatus for forming a high dielectric oxide film includes a controllable atomic oxygen source and a vaporized precursor source. A deposition chamber for receiving the atomic oxygen from the atomic oxygen source and vaporized precursor from the vaporized precursor source is used for deposition of the high dielectric oxide film on a surface of a structure located therein. The apparatus further includes a detection mechanism for detecting a characteristic of the deposition of the high dielectric oxide film on the surface of the structure. The controllable atomic oxygen source is controlled as a function of the detected characteristic.
    Type: Grant
    Filed: August 25, 1999
    Date of Patent: December 4, 2001
    Assignee: Micron Technology, Inc.
    Inventors: Scott J. DeBoer, Randhir P. S. Thakur
  • Publication number: 20010046753
    Abstract: The present invention relates to a method for forming an isolation trench structure in a semiconductor substrate without causing deleterious topographical depressions in the upper surface thereof which cause current and charge leakage to an adjacent active area. The inventive method forms a pad oxide upon a semiconductor substrate, and then forms a nitride layer on the pad oxide. The nitride layer is patterned with a mask and etched to expose a portion of the pad oxide layer and to protect an active area in the semiconductor substrate that remains covered with the nitride layer. A second dielectric layer is formed substantially conformably over the pad oxide layer and the remaining portions of the first dielectric layer. A spacer etch is then carried out to form a spacer from the second dielectric layer. The spacer is in contact with the remaining portion of the first dielectric layer. An isolation trench etch follows the spacer etch.
    Type: Application
    Filed: September 8, 1999
    Publication date: November 29, 2001
    Inventors: FERNANDO GONZALEZ, DAVID CHAPEK, RANDHIR P.S. THAKUR
  • Publication number: 20010040156
    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: Application
    Filed: September 3, 1999
    Publication date: November 15, 2001
    Inventors: SING PIN TAY, YAO-ZHI HU, RANDHIR P.S. THAKUR, ARNON GAT
  • Patent number: 6316800
    Abstract: Titanium boride (TiBx), zirconium boride (ZrBx) and hafnium boride (HfBx) barriers and electrodes for cell dielectrics for integrated circuits, particularly for DRAM cell capacitors. The barriers protect cell dielectrics from diffusion and other interaction with surrounding materials during subsequent thermal processing.
    Type: Grant
    Filed: May 4, 2000
    Date of Patent: November 13, 2001
    Assignee: Micron Technology Inc.
    Inventors: Husam N. Al-Shareef, Scott J. DeBoer, Dan Gealy, Randhir P. S. Thakur
  • Patent number: 6316308
    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: March 30, 2000
    Date of Patent: November 13, 2001
    Assignee: Micron Technology, Inc.
    Inventor: Randhir P. S. Thakur
  • Patent number: 6316372
    Abstract: In one aspect, the invention includes a semiconductor fabrication process, comprising: a) providing a substrate; b) forming a layer of silicon nitride over the substrate, the layer having a thickness; and c) enriching a portion of the thickness of the silicon nitride layer with silicon, the portion comprising less than or equal to about 95% of the thickness of the layer of silicon nitride. In another aspect, the invention includes a semiconductor fabrication process, comprising: a) providing a substrate; b) forming a layer of silicon nitride over the substrate, the layer having a thickness; and c) increasing a refractive index of a first portion of the thickness of the silicon nitride layer relative to a refractive index of a second portion of the silicon nitride layer, the first portion comprising less than or equal to about 95% of the thickness of the silicon nitride layer.
    Type: Grant
    Filed: April 7, 1998
    Date of Patent: November 13, 2001
    Assignee: Micron Technology, Inc.
    Inventors: Scott Jeffrey DeBoer, John T. Moore, Randhir P. S. Thakur, Mark Fischer
  • Publication number: 20010036752
    Abstract: A method of forming a high dielectric oxide film conventionally formed using a post formation oxygen anneal to reduce the leakage current of such film includes forming a high dielectric oxide film on a surface. The high dielectric oxide film has a dielectric constant greater than about 4 and includes a plurality of oxygen vacancies present during the formation of the film. The high dielectric oxide film is exposed during the formation thereof to an amount of atomic oxygen sufficient for reducing the number of oxygen vacancies and eliminating the post formation oxygen anneal of the high dielectric oxide film. Further, the amount of atomic oxygen used in the formation method may be controlled as a function of the amount of oxygen incorporated into the high dielectric oxide film during the formation thereof or be controlled as a function of the concentration of atomic oxygen in a process chamber in which the high dielectric oxide film is being formed.
    Type: Application
    Filed: February 27, 1997
    Publication date: November 1, 2001
    Inventors: SCOTT J. DEBOER, RANDHIR P.S. THAKUR
  • Publication number: 20010035541
    Abstract: The invention encompasses stacked semiconductor devices including gate stacks, wordlines, PROMs, conductive interconnecting lines, and methods for forming such structures. The invention also includes a method of forming a transistor gate comprising: a) forming gate dielectric layer; b) forming a polysilicon gate layer against the gate dielectric layer; and c) doping the polysilicon gate layer with a conductivity-enhancing dopant, the dopant being provided in a concentration gradient within the polysilicon layer, the concentration gradient increasing in a direction toward the gate dielectric layer. The invention also includes a wordline comprising: a) a polysilicon line; a substantially fluorine impervious barrier layer over the polysilicon line; and a b) layer of metal-silicide over the substantially fluorine impervious barrier layer.
    Type: Application
    Filed: June 11, 2001
    Publication date: November 1, 2001
    Inventors: Klaus Florian Schuegraf, Carl Powell, Randhir P. S. Thakur
  • Publication number: 20010034096
    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: Application
    Filed: March 30, 2000
    Publication date: October 25, 2001
    Inventor: Randhir P. S. Thakur
  • Patent number: 6300243
    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: Grant
    Filed: January 17, 2000
    Date of Patent: October 9, 2001
    Assignee: Micron Technology, Inc.
    Inventor: Randhir P. S. Thakur
  • Patent number: 6298470
    Abstract: This invention pertains to a method for the systematic development of integrated chip technology. The method may include obtaining empirical data of parameters for an existing integrated circuit manufacturing process and extrapolating the known data to a new technology to assess potential yields of the new technology from the known process. Further, process variables of the new process may be adjusted based upon the empirical data in order to optimize the yields of the new technology. A logic based computing system such as a fuzzy logic or neural-network system may be utilized. The computing system may also be utilized to improve the yields of an existing manufacturing process by adjust process variables within downstream process tools based upon data collected in upstream process for a particular semiconductor substrate or lot.
    Type: Grant
    Filed: April 15, 1999
    Date of Patent: October 2, 2001
    Assignee: Micron Technology, Inc.
    Inventors: Lyle Breiner, Randhir P. S. Thakur
  • Publication number: 20010023953
    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: Application
    Filed: March 1, 2001
    Publication date: September 27, 2001
    Inventors: Klaus Florian Schuegraf, Randhir P.S. Thakur
  • Patent number: 6294461
    Abstract: A new method and structure for improved contact using doped silicon is provided. The structures are integrated to several higher level embodiments. The improved contact has low contact resistivity. Improved junctions are thus provided between an IGFET device and substuent metallization layers. The improvements are obtained through the use of a silicon-germanium (Si—Ge) alloy. The alloy can be formed from depositing germanium onto the substrate and subsequently annealing the contact or by selectively depositing the preformed alloy into a contact opening. The above advantages are incorporated with relatively few process steps.
    Type: Grant
    Filed: June 13, 2000
    Date of Patent: September 25, 2001
    Assignee: Micron Technology, Inc.
    Inventor: Randhir P. S. Thakur
  • Publication number: 20010023135
    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: Application
    Filed: February 26, 2001
    Publication date: September 20, 2001
    Inventors: Fernando Gonzalez, Randhir P.S. Thakur
  • Patent number: 6291868
    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 silicide. Selective oxidation can be performed to reduce the amount of oxidation of selected materials in a structure containing multiple layers, such as the multi-layer 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: February 26, 1998
    Date of Patent: September 18, 2001
    Assignee: Micron Technology, Inc.
    Inventors: Ronald A. Weimer, Yongjun Jeff Hu, Pai Hung Pan, Deepa Ratakonda, James Beck, Randhir P. S. Thakur
  • Publication number: 20010017698
    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: February 26, 2001
    Publication date: August 30, 2001
    Inventors: Randhir P.S. Thakur, Michael Nuttall, J. Brett Rolfson, Robert James Burke
  • Patent number: 6281122
    Abstract: A semiconductor fabrication apparatus and methods for processing materials on a semiconductor wafer are disclosed. The fabrication apparatus is a processing chamber comprising: an ultraviolet radiation source and an infrared radiation source, the radiation sources symmetrically arranged such that radiation is substantially uniform throughout the chamber and the radiation sources being capable of being used as a film deposition radiation source or a film annealing radiation source or both; an ultraviolet radiation sensor and an infrared radiation sensor to provide a feedback loop to the ultraviolet radiation source and to the infrared radiation source, respectively, so that a desired level of ultraviolet radiation and infrared radiation is maintained inside the chamber.
    Type: Grant
    Filed: November 23, 1999
    Date of Patent: August 28, 2001
    Assignee: Micron Technology, Inc.
    Inventor: Randhir P. S. Thakur