Patents by Inventor Vishnu K. Agarwal

Vishnu K. Agarwal 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: 6596583
    Abstract: Capacitors having increased capacitance include an enhanced-surface-area (rough-surfaced) electrically conductive layer or other layers that are compatible with the high-dielectric constant materials. In one approach, an enhanced-surface-area electrically conductive layer for such capacitors is formed by processing a ruthenium oxide layer at high temperature at or above 500° C. and low pressure 75 torr or below, most desirably 5 torr or below, to produce a roughened ruthenium layer having a textured surface with a mean feature size of at least about 100 Angstroms. The initial ruthenium oxide layer may be provided by chemical vapor deposition techniques or sputtering techniques or the like. The layer may be formed over an underlying electrically conductive layer. The processing may be performed in an inert ambient or in a reducing ambient.
    Type: Grant
    Filed: October 29, 2001
    Date of Patent: July 22, 2003
    Assignee: Micron Technology, Inc.
    Inventors: Vishnu K. Agarwal, Garo Derderian, Gurtej S. Sandhu, Weimin M. Li, Mark Visokay, Cem Basceri, Sam Yang
  • Publication number: 20030132428
    Abstract: Undesirable transistor leakage in transistor structures becomes greatly reduced in substrates having a doped implant region formed via pulling back first and second layers of a process stack. A portion of the substrate, which also has first and second layers deposited thereon, defines the process stack. The dopant is selected having the same n- or p-typing as the substrate. Through etching, the first and second layers of the process stack become pulled back from a trench wall of the substrate to form the implant region. Occupation of the implant region by the dopant prevents undesirable transistor leakage because the electrical characteristics of the implant region are so significantly changed, in comparison to central areas of the substrate underneath the first layer, that the threshold voltage of the implant region is raised to be about equivalent to or greater than the substantially uniform threshold voltage in the central area.
    Type: Application
    Filed: January 17, 2002
    Publication date: July 17, 2003
    Applicant: Micron Technology, Inc.
    Inventors: Vishnu K. Agarwal, Fred Fishburn, Rongsheng Yang, Howard E. Rhodes, Jeffrey A. McKee
  • Patent number: 6590246
    Abstract: Systems, devices, structures, and methods are described that inhibit atomic migration that creates an open contact between a metallization layer and a conductive layer of a semiconductor structure. A layer of an inhibiting substance may be used to inhibit a net flow of atoms so as to maintain conductivity between the metallization layer and the conductive layer of the semiconductor structure. Such layer of inhibiting substance acts even with the presence of point defects for a given temperature.
    Type: Grant
    Filed: February 8, 2000
    Date of Patent: July 8, 2003
    Assignee: Micron Technology, Inc.
    Inventor: Vishnu K. Agarwal
  • Patent number: 6580115
    Abstract: A conductive composition of tantalum nitride is disclosed for use as a conductive element in integrated circuits. The layer is shown employed in a memory cell, and in particular in a cell incorporating a high dielectric constant material such as Ta2O5. The tantalum nitride can serve as a barrier layer protecting an underlying contact plug, or can serve as the top or bottom electrode of the memory cell capacitor. The titanium nitride has a nitrogen content of between about 7% and 40%, thereby balancing susceptibility to oxidation with conductivity. In an illustrative embodiment, the titanium nitride layer is a bilayer formed of a thick portion having a low nitrogen concentration, and thin portion with a higher nitrogen concentration. The thick portion thus carries the bulk of the current with low resistivity, while the thinner portion is highly resistant to oxidation.
    Type: Grant
    Filed: July 19, 2001
    Date of Patent: June 17, 2003
    Assignee: Micron Technology, Inc.
    Inventor: Vishnu K. Agarwal
  • Patent number: 6576564
    Abstract: The present invention provides a plasma processing system comprising a remote plasma activation region for formation of active gas species, a transparent transfer tube coupled between the remote activation region and a semiconductor processing chamber, and a source of photo energy for maintaining activation of the active species during transfer from the remote plasma activation region to the processing chamber. The source of photo energy preferably includes an array of UV lamps. Additional UV lamps may also be used to further sustain active species and assist plasma processes by providing additional in-situ energy through a transparent window of the processing chamber. The system can be utilized for annealing.
    Type: Grant
    Filed: December 7, 2000
    Date of Patent: June 10, 2003
    Assignee: Micron Technology, Inc.
    Inventor: Vishnu K. Agarwal
  • Patent number: 6570204
    Abstract: A method of forming a pair of capacitors having a common capacitor electrode includes forming a pair of spaced first capacitor electrodes within insulating material. The first electrodes have uppermost surfaces which are below an uppermost surface of the insulating material. Some of the insulating material is removed about the first capacitor electrodes and a path is provided within the insulating material lower than its uppermost surface between the spaced first electrodes. A capacitor dielectric layer is formed over the first capacitor electrodes. A second capacitor electrode layer is formed over the capacitor dielectric layer common to the spaced first capacitor electrodes and within the path. A method of forming DRAM circuitry includes forming an array of capacitor storage node electrodes over a substrate. A capacitor cell plate pattern is formed over the substrate. Conductive material is deposited over the substrate and into the capacitor cell plate pattern.
    Type: Grant
    Filed: September 1, 2000
    Date of Patent: May 27, 2003
    Assignee: Micron Technology, Inc.
    Inventor: Vishnu K. Agarwal
  • Patent number: 6562182
    Abstract: A method and apparatus for endpointing a planarization process of a microelectronic substrate. In one embodiment, the apparatus may include a species analyzer that receives a slurry resulting from the planarization process and analyzes the slurry to determine the presence of an endpointing material implanted beneath the surface of the microelectronic substrate. The species analyzer may include a mass spectrometer or a spectrum analyzer. In another embodiment, the apparatus may include a radiation source that directs impinging radiation toward the microelectronic substrate, exciting atoms of the substrate, which in turn produce an emitted radiation. A radiation detector is positioned proximate to the substrate to receive the emitted radiation and determine the endpoint by determining the intensity of the radiation emitted by the endpointing material.
    Type: Grant
    Filed: July 20, 2001
    Date of Patent: May 13, 2003
    Assignee: Micron Technology, Inc.
    Inventor: Vishnu K. Agarwal
  • Publication number: 20030087164
    Abstract: The present invention provides a method and apparatus for producing 0 degree light and 180 degree phase shifted light having substantially equal intensities as both lights exit an alternating phase shift reticle. A material is inserted within the etched portion of the 180 degree phase shift channel of a reticle, wherein the material contains an index of refraction such that the first order light (+1, −1) is propagated through the 180 degree channel. The end result is a 180 degree phase shifted light having an intensity substantially equal to that of the 0 degree light.
    Type: Application
    Filed: October 21, 2002
    Publication date: May 8, 2003
    Inventors: William A. Stanton, Vishnu K. Agarwal
  • Patent number: 6555863
    Abstract: In one aspect, the invention encompasses a semiconductor circuit construction including a material which comprises Q, R, S and B. In such construction, Q comprises one or more refractory metals, R is selected from the group consisting of one or more of tungsten, aluminum and silicon, S is selected from the group consisting of one or more of nitrogen and oxygen, and B is boron. Also, in such construction R and Q do not comprise a common element. In another aspect, the invention encompasses a method of forming a capacitor. A first capacitor electrode is formed, a diffusion barrier layer is formed proximate the first capacitor electrode, and a dielectric layer is formed to be separated from: the: first capacitor electrode by the diffusion barrier layer. A second capacitor electrode is formed to be separated from the first electrode by the dielectric layer.
    Type: Grant
    Filed: May 8, 2000
    Date of Patent: April 29, 2003
    Assignee: Micron Technology, Inc.
    Inventor: Vishnu K. Agarwal
  • Publication number: 20030068876
    Abstract: In accordance with one embodiment of the present invention, a method of interfacing a poly-metal stack and a semiconductor substrate is provided where an etch stop layer is provided in a polysilicon region of the stack. The present invention also addresses the relative location of the etch stop layer in the polysilicon region and a variety of stack materials and oxidation methods. The etch stop layer may be patterned within the poly or may be a continuous conductive etch stop layer in the poly. The present invention also relates more broadly to a process for forming wordline architecture of a memory cell. In accordance with another embodiment of the present invention, a semiconductor structure is provided comprising a poly-metal stack formed over a semiconductor substrate where the interface between an oxidation barrier placed over the stack and an oxidized portion of the stack lies along the sidewall of the poly.
    Type: Application
    Filed: October 4, 2001
    Publication date: April 10, 2003
    Inventor: Vishnu K. Agarwal
  • Publication number: 20030047808
    Abstract: Container structures for use in integrated circuits and methods of their manufacture. The container structures include a bottom conductive layer, a top conductive layer and a dielectric layer interposed between the bottom conductive layer and the top conductive layer. The container structures further include a diffusion barrier layer interposed between the dielectric layer and the bottom conductive layer. The diffusion barrier layer acts to inhibit atomic diffusion to at least a portion of the bottom conductive layer, particularly atomic diffusion of oxygen during formation or annealing of the dielectric layer. The container structures are especially adapted for use as container capacitors. The container capacitors are further adapted for use in memory cells and apparatus incorporating such memory cells, as well as other integrated circuits.
    Type: Application
    Filed: October 9, 2002
    Publication date: March 13, 2003
    Applicant: Micron Technology, Inc.
    Inventor: Vishnu K. Agarwal
  • Publication number: 20030040199
    Abstract: The present invention provides a plasma processing system comprising a remote plasma activation region for formation of active gas species, a transparent transfer tube coupled between the remote activation region and a semiconductor processing chamber, and a source of photo energy for maintaining activation of the active species during transfer from the remote plasma activation region to the processing chamber. The source of photo energy preferably includes an array of UV lamps. Additional UV lamps may also be used to further sustain active species and assist plasma processes by providing additional in-situ energy through a transparent window of the processing chamber. The system can be utilized for annealing.
    Type: Application
    Filed: October 8, 2002
    Publication date: February 27, 2003
    Inventor: Vishnu K. Agarwal
  • Patent number: 6524751
    Abstract: The present invention provides a method and apparatus for producing 0 degree light and 180 degree phase shifted light having substantially equal intensities as both lights exit an alternating phase shift reticle. A material is inserted within the etched portion of the 180 degree phase shift channel of a reticle, wherein the material contains an index of refraction such that the first order light (+1, −1) is propagated through the 180 degree channel. The end result is a 180 degree phase shifted light having an intensity substantially equal to that of the 0 degree light.
    Type: Grant
    Filed: March 6, 2000
    Date of Patent: February 25, 2003
    Assignee: Micron Technology, Inc.
    Inventors: William A. Stanton, Vishnu K. Agarwal
  • Publication number: 20030030093
    Abstract: A capacitor forming method can include forming an insulation layer over a substrate and forming a barrier layer to threshold voltage shift inducing material over the substrate. An opening can be formed at least into the insulation layer and a capacitor dielectric layer formed at least within the opening. Threshold voltage inducing material can be provided over the barrier layer but be retarded in movement into an electronic device comprised by the substrate. The dielectric layer can comprise a tantalum oxide and the barrier layer can include a silicon nitride. Providing threshold voltage shift inducing material can include oxide annealing dielectric layer such as with N2O. The barrier layer can be formed over the insulation layer, the insulation layer can be formed over the barrier layer, or the barrier layer can be formed over a first insulation layer with a second insulation layer formed over the barrier layer.
    Type: Application
    Filed: August 19, 2002
    Publication date: February 13, 2003
    Applicant: Micron Technology, Inc.
    Inventors: Vishnu K. Agarwal, F. Daniel Gealy, Kunal R. Parekh, Randhir P.S. Thakur
  • Patent number: 6517668
    Abstract: A method and apparatus for endpointing a planarization process of a microelectronic substrate. In one embodiment, the apparatus may include a species analyzer that receives a slurry resulting from the planarization process and analyzes the slurry to determine the presence of an endpointing material implanted beneath the surface of the microelectronic substrate. The species analyzer may include a mass spectrometer or a spectrum analyzer. In another embodiment, the apparatus may include a radiation source that directs impinging radiation toward the microelectronic substrate, exciting atoms of the substrate, which in turn produce an emitted radiation. A radiation detector is positioned proximate to the substrate to receive the emitted radiation and determine the endpoint by determining the intensity of the radiation emitted by the endpointing material.
    Type: Grant
    Filed: July 20, 2001
    Date of Patent: February 11, 2003
    Assignee: Micron Technology, Inc.
    Inventor: Vishnu K. Agarwal
  • Patent number: 6511900
    Abstract: A diffusion barrier layer comprising TiNxBy is disclosed for protection of gate oxide layers in integrated transistors. The diffusion barrier layer can be fabricated by first forming a TiN layer and then incorporating boron into the TiN layer. The diffusion barrier layer can also be fabricated by forming a TiNxBy layer using a TDMAT process including boron. The diffusion barrier layer can also be fabricated by forming a TiNxBy layer using a CVD process.
    Type: Grant
    Filed: December 15, 2000
    Date of Patent: January 28, 2003
    Assignee: Micron Technology, Inc.
    Inventors: Vishnu K. Agarwal, Gurtej S. Sandhu
  • Publication number: 20030015750
    Abstract: An intermediate metal plug is used to raise the platform to which contact is to be made. In the illustrated process, a partial bit line plug is formed adjacent a stacked capacitor, and an interlevel dielectric formed over the capacitor. The bit line contact is completed by extending a via from the bit line, formed above the interlevel dielectric, down to the level of the intermediate plug, and the via is filled with metal. The height of the via to be filled is thus reduced by the height of the intermediate plug. In one embodiment, the intermediate plug is slightly shorter than an adjacent container-shaped capacitor. In another embodiment, the intermediate plug is about as high as an adjacent stud capacitor.
    Type: Application
    Filed: September 4, 2002
    Publication date: January 23, 2003
    Inventors: Scott J. Deboer, Vishnu K. Agarwal
  • Publication number: 20030011016
    Abstract: A ferroelectric or high dielectric constant capacitor having a multilayer lower electrode comprising at least two layers—a platinum layer and a platinum-rhodium layer—for use in a random access memory (RAM) cell. The platinum layer of the lower electrode adjoins the capacitor dielectric, which is a ferroelectric or high dielectric constant dielectric such as BST, PZT, SBT or tantalum pentoxide. The platinum-rhodium layer serves as an oxidation barrier and may also act as an adhesion layer for preventing separation of the lower electrode from the substrate, thereby improving capacitor performance. The multilayer electrode may have titanium and/or titanium nitride layers under the platinum-rhodium layer for certain applications. The capacitor has an upper electrode which may be a conventional electrode or which may have a multilayer structure similar to that of the lower electrode. Processes for manufacturing the multilayer lower electrode and the capacitor are also disclosed.
    Type: Application
    Filed: September 4, 2002
    Publication date: January 16, 2003
    Inventors: Vishnu K. Agarwal, Garo J. Derderian, F. Daniel Gealy
  • Publication number: 20030003697
    Abstract: Capacitors having increased capacitance include an enhanced-surface-area (rough-surfaced) electrically conductive layer or other layers that are compatible with the high-dielectric constant materials. In one approach, an enhanced-surface-area electrically conductive layer for such capacitors is formed by processing a ruthenium oxide layer at high temperature at or above 500° C. and low pressure 75 torr or below, most desirably 5 torr or below, to produce a roughened ruthenium layer having a textured surface with a mean feature size of at least about 100 Angstroms. The initial ruthenium oxide layer may be provided by chemical vapor deposition techniques or sputtering techniques or the like. The layer may be formed over an underlying electrically conductive layer. The processing may be performed in an inert ambient or in a reducing ambient.
    Type: Application
    Filed: August 21, 2002
    Publication date: January 2, 2003
    Applicant: Micron Techology, Inc.
    Inventors: Vishnu K. Agarwal, Garo Derderian, Gurtej S. Sandhu, Weimin M. Li, Mark Visokay, Cem Basceri, Sam Yang
  • Publication number: 20020195639
    Abstract: An intermediate metal plug is used to raise the platform to which contact is to be made. In the illustrated process, a partial bit line plug is formed adjacent a stacked capacitor, and an interlevel dielectric formed over the capacitor. The bit line contact is completed by extending a via from the bit line, formed above the interlevel dielectric, down to the level of the intermediate plug, and the via is filled with metal. The height of the via to be filled is thus reduced by the height of the intermediate plug. In one embodiment, the intermediate plug is slightly shorter than an adjacent container-shaped capacitor. In another embodiment, the intermediate plug is about as high as an adjacent stud capacitor.
    Type: Application
    Filed: September 4, 2002
    Publication date: December 26, 2002
    Inventors: Scott J. Deboer, Vishnu K. Agarwal