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: 20030207556
    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: Application
    Filed: June 4, 2003
    Publication date: November 6, 2003
    Inventors: Ronald A. Weimer, Yongjun Jeff Hu, Pai Hung Pan, Deepa Ratakonda, James Beck, Randhir P.S. Thakur
  • Patent number: 6635568
    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 opposing 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: September 7, 2001
    Date of Patent: October 21, 2003
    Assignee: Micron Technology, Inc.
    Inventor: Randhir P. S. Thakur
  • Publication number: 20030189253
    Abstract: The invention encompasses stacked semiconductor devices including gate stacks, wordlines, PROMs, conductive interconnecting lines, and methods for forming such structures. In one aspect, the invention includes a method of forming a conductive line comprising: a) forming a polysilicon layer; forming a silicide layer against the polysilicon layer; b) providing a conductivity-enhancing impurity within the silicide layer; and c) providing the polysilicon layer and the silicide layer into a conductive line shape. In another aspect, the invention includes a programmable-read-only-memory device comprising: a) a first dielectric layer over a substrate; b) a floating gate over the first dielectric layer; c) a second dielectric layer over the floating gate; d) a conductive line over the second dielectric layer; and e) a metal-silicide layer over the conductive line, the metal-silicide layer comprising a Group III dopant or a Group V dopant.
    Type: Application
    Filed: June 4, 2001
    Publication date: October 9, 2003
    Inventors: Klaus Florian Schuegraf, Randhir P.S. Thakur
  • Patent number: 6627508
    Abstract: The invention pertains to semiconductor circuit components and capacitors, and to methods of forming capacitors and semiconductor circuit components. In one aspect, the invention includes a method of forming a dielectric layer comprising: a) forming a first tantalum-comprising layer; and b) forming a second tantalum-comprising layer over the first tantalum-comprising layer, the second tantalum-comprising layer comprising nitrogen. In another aspect, the invention includes a method of forming a capacitor comprising: a) forming a first capacitor plate; b) forming a first layer over the first capacitor plate, the first layer comprising tantalum and oxygen; c) annealing the first layer in the presence of an ambient comprising a nitrogen-comprising gas containing at least one compound selected from a group consisting of ammonia, hydrazine and hydrazoic acid; the annealing forming a second layer over the first layer; and d) forming a second capacitor plate over the second layer.
    Type: Grant
    Filed: October 6, 2000
    Date of Patent: September 30, 2003
    Assignee: Micron Technology, Inc.
    Inventors: Scott Jeffrey DeBoer, F. Daniel Gealy, Randhir P. S. Thakur
  • Publication number: 20030172872
    Abstract: An apparatus for cyclical depositing of thin films on semiconductor substrates, comprising a process chamber having a gas distribution system with separate paths for process gases and an exhaust system synchronized with operation of valves dosing the process gases into a reaction region of the chamber.
    Type: Application
    Filed: January 27, 2003
    Publication date: September 18, 2003
    Applicant: APPLIED MATERIALS, INC.
    Inventors: Randhir P.S. Thakur, Alfred W. Mak, Ming Xi, Walter Benjamin Glenn, Ahmad A. Khan, Ayad A. Al-Shaikh, Avgerinos V. Gelatos, Salvador P. Umotoy
  • Patent number: 6620740
    Abstract: In one aspect, a method of forming an electronic device includes forming a layer of undoped oxide over a layer of doped oxide. A first electrode is formed proximate thereto. With the undoped oxide layer being outwardly exposed, a silicon nitride layer is formed on the undoped oxide layer and over the first electrode by low pressure chemical vapor deposition to a thickness of no greater than 80 Angstroms. The substrate is exposed to oxidizing conditions of at least 700° C. to form a silicon dioxide layer over the silicon nitride layer, with the thickness of silicon nitride on the undoped 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. Other aspects are contemplated.
    Type: Grant
    Filed: February 28, 2002
    Date of Patent: September 16, 2003
    Assignee: Micron Technology, Inc.
    Inventor: Randhir P. S. Thakur
  • Patent number: 6620534
    Abstract: A method of forming a film having enhanced reflow characteristics at low thermal budget is disclosed, in which a surface layer of material is formed above a base layer of material, the surface layer having a lower melting point than the base layer. In this way, a composite film having two layers is created. After reflow, the surface layer can be removed using conventional methods.
    Type: Grant
    Filed: January 31, 2001
    Date of Patent: September 16, 2003
    Assignee: Micron Technology, Inc.
    Inventors: Gurtei Sandhu, Randhir P. S. Thakur
  • Patent number: 6611032
    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: Grant
    Filed: June 11, 2001
    Date of Patent: August 26, 2003
    Assignee: Micron Technology, Inc.
    Inventors: Klaus Florian Schuegraf, Carl Powell, Randhir P. S. Thakur
  • Publication number: 20030153142
    Abstract: A polysilicon film is formed with enhanced selectivity by flowing chlorine during the formation of the film. The chlorine acts as an etchant to insulative areas adjacent polysilicon structures on which the film is desired to be formed. Bottom electrodes for capacitors are formed using this process, followed by an anneal to create hemishperical grain (HSG) polysilicon. Multilayer capacitor containers are formed in a non-oxidizing ambient so that no oxide is formed between the layers. The structure formed is planarized to form separate containers made from doped and undoped amorphous silicon layers. Selected ones of undoped layers are seeded in a chlorine containing environment and annealed to form HSG. A dielectric layer and second electrode are formed to complete the cell capacitor.
    Type: Application
    Filed: February 18, 2003
    Publication date: August 14, 2003
    Applicant: Micron Technology, Inc.
    Inventors: Randhir P.S. Thakur, James Pan
  • Patent number: 6602798
    Abstract: Stress resulting from silicon nitride is diminished by forming an oxidation mask with silicon nitride having a graded silicon concentration. Grading is accomplished by changing the silicon content in the silicon nitride by varying the amount of hydride, such as dichlorosilane (DCS), mixed with ammonia. The silicon nitride can be graded in a substantially linear or non-linear fashion. Silicon nitride formed with higher levels of DCS mixed with ammonia is referred to as silicon rich nitride because of its relatively higher silicon content. In one embodiment, the graded silicon nitride may be formed with one type of non-linear silicon grading, an abrupt junction. In other embodiments, the silicon nitride is formed in a variety of shapes fashioned during or after silicon nitride growth. In one embodiment, the stress from the silicon nitride is reduced by forming a polysilicon buffer layer between two silicon nitride layers.
    Type: Grant
    Filed: March 2, 2000
    Date of Patent: August 5, 2003
    Assignee: Micron Technology, Inc.
    Inventors: Randhir P. S. Thakur, Kevin G. Donohoe, Zhiqiang Wu, Alan R. Reinberg
  • Patent number: 6596595
    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: July 20, 2000
    Date of Patent: July 22, 2003
    Assignee: Micron Technology, Inc.
    Inventors: Ronald A. Weimer, Yongjun Jeff Hu, Pai Hung Pan, Deepa Ratakonda, James Beck, Randhir P. S. Thakur
  • Patent number: 6594013
    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: Grant
    Filed: October 29, 2001
    Date of Patent: July 15, 2003
    Assignee: Micron Technology, Inc.
    Inventors: Randhir P. S. Thakur, Michael Nuttall, J. Brett Rolfson, Robert James Burke
  • Patent number: 6592661
    Abstract: A method of manufacturing semiconductor wafers in a processing chamber having at least one radiant heat source is provided. The method includes the steps of applying a predetermined amount of power to the radiant heat source and positioning a wafer within the processing chamber. The predetermined amount of power applied to the at least one radiant heat source is set such that the wafer reaches a predetermined temperature in a predetermined amount of time for carrying out a desired process in the processing chamber. The processing chamber is particularly suited for very low pressure environments and may be used to form HSG in a clustered or non-clustered system. A reflective plate may be used so that the radiated properties of the wafer are substantially independent of the emissivity of the wafer thereby minimizing emissivity variation from one wafer to another. Another plate may be used to form an isothermal cavity between the plate and the wafer to minimize emissivity variation from one wafer to another.
    Type: Grant
    Filed: February 25, 1998
    Date of Patent: July 15, 2003
    Assignee: Micron Technology, Inc.
    Inventors: Randhir P. S. Thakur, Ronald A. Weimer
  • Patent number: 6593183
    Abstract: A semiconductor processing method includes forming a conductively doped plug of semiconductive material within a first insulative layer. A barrier layer to out diffusion of dopant material from the semiconductive material is formed over the doped plug. Examples include undoped oxide, such as silicon dioxide, and Si3N4. A second insulative layer is formed over the barrier layer. Conductive material is formed through the second insulative layer and into electrical connection with the doped plug. In another implementation, spaced first and second conductively doped regions of semiconductive material are formed. A barrier layer to out diffusion of dopant material from the semiconductive material is formed over at least one of the first and second regions, and preferably over both. Then, a capacitor having a capacitor dielectric layer comprising Ta2O5 is formed over the other of the first and second regions.
    Type: Grant
    Filed: November 8, 2000
    Date of Patent: July 15, 2003
    Assignee: Micron Technology, Inc.
    Inventors: Kunal R. Parekh, Randhir P. S. Thakur
  • Publication number: 20030127427
    Abstract: A method of forming a contact in an integrated circuit between a first metalization layer and a silicon substrate. In one embodiment the method comprises forming a premetal dielectric layer over the silicon substrate, etching a contact hole through the premetal dielectric layer and then forming a thin silicon nitride layer on an outer surface of the contact hole. The silicon nitride layer reduces overetching that may otherwise occur when oxidation build-up is removed from the silicon interface within the contact hole by a preclean process. After the preclean process, the contact hole is then filled with one or more conductive materials. In various embodiments the silicon nitride layer is formed by exposing the contact hole to a nitrogen plasma, depositing the layer by a chemical vapor deposition process and depositing the layer by an atomic layer deposition process. In other embodiments, the method is applicable to the formation of vias through intermetal dielectric layers.
    Type: Application
    Filed: January 7, 2002
    Publication date: July 10, 2003
    Applicant: Applied Materials, Inc.
    Inventors: Zheng Yuan, Steve Ghanayem, Randhir P.S. Thakur
  • Publication number: 20030113968
    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 using feed gases comprising a silicon hydride, H2 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.
    Type: Application
    Filed: January 7, 2003
    Publication date: June 19, 2003
    Inventor: Randhir P.S. Thakur
  • Patent number: 6573552
    Abstract: A capacitor with Enhanced capacitance per cell area is provided. A container supported by a substrate is formed, followed by a first layer of undoped substantially amorphous silicon. Next, a layer of heavily doped amorphous silicon is formed on the first layer. A second layer of undoped amorphous silicon is formed on the doped layer. The layers are formed in a non-oxidizing ambient so that no oxide is formed between the layers. The structure formed is planarized to form separate containers made from the doped and undoped amorphous silicon layers. Any remaining oxide is then removed from the exterior sidewalls. Selected ones of the first and second undoped layers are seeded and annealed to convert the first and second layers to HSG. A dielectric layer and second electrode are formed to complete the cell capacitor.
    Type: Grant
    Filed: February 28, 2000
    Date of Patent: June 3, 2003
    Assignee: Micron Technology, Inc.
    Inventor: Randhir P. S. Thakur
  • Patent number: 6548852
    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: March 1, 2001
    Date of Patent: April 15, 2003
    Assignee: Micron Technology, Inc.
    Inventors: Klaus Florian Schuegraf, Randhir P. S. Thakur
  • Publication number: 20030062566
    Abstract: The invention encompasses stacked semiconductor devices including gate stacks, wordlines, PROMs, conductive interconnecting lines, and methods for forming such structures. In one aspect, the invention includes a method of forming a conductive line comprising: a) forming a polysilicon layer; forming a silicide layer against the polysilicon layer; b) providing a conductivity-enhancing impurity within the silicide layer; and c) providing the polysilicon layer and the silicide layer into a conductive line shape. In another aspect, the invention includes a programmable-read-only-memory device comprising: a) a first dielectric layer over a substrate; b) a floating gate over the first dielectric layer; c) a second dielectric layer over the floating gate; d) a conductive line over the second dielectric layer; and e) a metal-silicide layer over the conductive line, the metal-silicide layer comprising a Group III dopant or a Group V dopant.
    Type: Application
    Filed: June 11, 1999
    Publication date: April 3, 2003
    Inventors: KLAUS FLORIAN SCHUEGRAF, RANDHIR P.S. THAKUR
  • Patent number: 6541811
    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: June 12, 2001
    Date of Patent: April 1, 2003
    Assignee: Micron Technology, Inc.
    Inventors: Randhir P. S. Thakur, Garry A. Mercaldi, Michael Nuttall