Patents by Inventor Padmanabhan Krishnaraj

Padmanabhan Krishnaraj 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: 20050124166
    Abstract: A continuous in situ process of deposition, etching, and deposition is provided for forming a film on a substrate using a plasma process. The etch-back may be performed without separate plasma activation of the etchant gas. The sequence of deposition, etching, and deposition permits features with high aspect ratios to be filled, while the continuity of the process results in improved uniformity.
    Type: Application
    Filed: January 13, 2005
    Publication date: June 9, 2005
    Applicants: Applied Materials, Inc., A Delaware corporation
    Inventors: Padmanabhan Krishnaraj, Pavel Ionov, Canfeng Lai, Michael Cox, Shamouil Shamouilian
  • Patent number: 6890597
    Abstract: A combination of deposition and polishing steps are used to permit improved uniformity of a film after the combination of steps. Both the deposition and polishing are performed with processes that vary across the substrate. The combination of the varying deposition and etching rates results in a film that is substantially planar after the film has been polished. In some instances, it may be easier to control the variation of one of the two processes than the other so that the more controllable process is tailored to accommodate nonuniformities introduced by the less controllable process.
    Type: Grant
    Filed: May 9, 2003
    Date of Patent: May 10, 2005
    Assignee: Applied Materials, Inc.
    Inventors: Padmanabhan Krishnaraj, Bruno Geoffrion, Michael S. Cox, Lin Zhang, Bikram Kapoor, Anchuan Wang, Zhenjiang Cui
  • Publication number: 20050079715
    Abstract: A method of depositing a high density plasma silicon oxide layer having improved gapfill capabilities. In one embodiment the method includes flowing a process gas consisting of a silicon-containing source, an oxygen-containing source and helium into a substrate processing chamber and forming a plasma from the process gas. The ratio of the flow rate of the helium with respect to the combined flow rate of the silicon source and oxygen source is between 0.5:1 and 3.0:1 inclusive. In one particular embodiment, the process gas consists of monosilane (SiH4), molecular oxygen (O2) and helium.
    Type: Application
    Filed: October 1, 2004
    Publication date: April 14, 2005
    Applicant: Applied Materials, Inc.
    Inventors: Zhong Hua, Dong Li, Zhengquan Tan, Zhuang Li, Michael Kwan, Bruno Geoffrion, Padmanabhan Krishnaraj
  • Patent number: 6869880
    Abstract: A continuous in situ process of deposition, etching, and deposition is provided for forming a film on a substrate using a plasma process. The etch-back may be performed without separate plasma activation of the etchant gas. The sequence of deposition, etching, and deposition permits features with high aspect ratios to be filled, while the continuity of the process results in improved uniformity.
    Type: Grant
    Filed: January 24, 2002
    Date of Patent: March 22, 2005
    Assignee: Applied Materials, Inc.
    Inventors: Padmanabhan Krishnaraj, Pavel Ionov, Canfeng Lai, Michael Santiago Cox, Shamouil Shamouilian
  • Patent number: 6863019
    Abstract: A method of cleaning a semiconductor fabrication processing chamber involves recirculation of cleaning gas components. Consequently, input cleaning gas is utilized efficiently, and undesirable emissions are reduced. The method includes flowing a cleaning gas to an inlet of a processing chamber, and exposing surfaces of the processing chamber to the cleaning gas to clean the surfaces, thereby producing a reaction product. The method further includes removing an outlet gas including the reaction product from an outlet of the processing chamber, separating at least a portion of the reaction product from the outlet gas, and recirculating a portion of the outlet gas to the inlet of the processing chamber.
    Type: Grant
    Filed: May 30, 2002
    Date of Patent: March 8, 2005
    Assignee: Applied Materials, Inc.
    Inventors: Shamouil Shamouilian, Canfeng Lai, Michael Santiago Cox, Padmanabhan Krishnaraj, Tsutomu Tanaka, Sebastien Raoux, Peter I. Porshnev, Thomas Nowak
  • Publication number: 20050019494
    Abstract: A method of depositing a silica glass insulating film over a substrate. In one embodiment the method comprises exposing the substrate to a silicon-containing reactant introduced into a chamber in which the substrate is disposed such that one or more layers of the silicon-containing reactant are adsorbed onto the substrate; purging or evacuating the chamber of the silicon-containing reactant; converting the silicon-containing reactant into a silica glass insulating compound by exposing the substrate to oxygen radicals formed from a second reactant while biasing the substrate to promote a sputtering effect, wherein an average atomic mass of all atomic constituents in the second reactant is less than or equal to an average atomic mass of oxygen; and repeating the exposing, purging/evacuating and exposing sequence a plurality of times until a desired film thickness is reached.
    Type: Application
    Filed: July 25, 2003
    Publication date: January 27, 2005
    Applicant: APPLIED MATERIALS, INC., A Delaware Corporation
    Inventors: Farhad Moghadam, Michael Cox, Padmanabhan Krishnaraj, Thanh Pham
  • Publication number: 20040251236
    Abstract: A deposition / etching /deposition process is provided for filling a gap in a surface of a substrate. A liner is formed over the substrate so that distinctive reaction products are formed when it is exposed to a chemical etchant. The detection of such reaction products thus indicates that the portion of the film deposited during the first etching has been removed to an extent that further exposure to the etchant may remove the liner and expose underlying structures. Accordingly, the etching is stopped upon detection of distinctive reaction products and the next deposition in the deposition /etching /deposition process is begun.
    Type: Application
    Filed: May 23, 2003
    Publication date: December 16, 2004
    Applicant: Applied Materials, Inc.
    Inventors: Lin Zhang, Xiaolin Chen, DongQing Li, Thanh N. Pham, Farhad K. Moghadam, Shuang Li, Padmanabhan Krishnaraj
  • Publication number: 20040231798
    Abstract: A replaceable gas nozzle is insertable in a gas distributor ring of a substrate processing chamber and that can be shielded within the chamber. The replaceable gas nozzle has a longitudinal ceramic body having a channel to direct the flow of the gas into the chamber. The ceramic body includes a first external thread to mate with the gas distributor ring, and a second external thread to receive a heat shield. The channel has an inlet to receive the gas from the gas distributor ring and a pinhole outlet to release the gas into the chamber. A heat shield can be used to shield the nozzle extending into the chamber. The heat shield has a hollow member configured to be coupled with the nozzle that has an internal dimension sufficiently large to be disposed around at least a portion of the nozzle. The hollow member also has an extension which projects distally of the outlet of the nozzle and a heat shield opening for the process gas to flow therethrough from the nozzle outlet.
    Type: Application
    Filed: April 16, 2004
    Publication date: November 25, 2004
    Applicant: Applied Materials, Inc.
    Inventors: Sudhir Gondhalekar, Padmanabhan Krishnaraj, Tom K. Cho, Muhammad Rasheed, Hemant Mungekar, Thanh N. Pham, Zhong Qiang Hua
  • Publication number: 20040224090
    Abstract: A combination of deposition and polishing steps are used to permit improved uniformity of a film after the combination of steps. Both the deposition and polishing are performed with processes that vary across the substrate. The combination of the varying deposition and etching rates results in a film that is substantially planar after the film has been polished. In some instances, it may be easier to control the variation of one of the two processes than the other so that the more controllable process is tailored to accommodate nonuniformities introduced by the less controllable process.
    Type: Application
    Filed: May 9, 2003
    Publication date: November 11, 2004
    Applicant: Applied Materials, Inc.
    Inventors: Padmanabhan Krishnaraj, Bruno Geoffrion, Michael S. Cox, Lin Zhang, Bikram Kapoor, Anchuan Wang, Zhenjiang Cui
  • Patent number: 6812153
    Abstract: A method of depositing a high density plasma silicon oxide layer having improved gapfill capabilities. In one embodiment the method includes flowing a process gas consisting of a silicon-containing source, an oxygen-containing source and helium into a substrate processing chamber and forming a plasma from the process gas. The ratio of the flow rate of the helium with respect to the combined flow rate of the silicon source and oxygen source is between 0.5:1 and 3.0:1 inclusive. In one particular embodiment, the process gas consists of monosilane (SiH4), molecular oxygen (O2) and helium.
    Type: Grant
    Filed: April 30, 2002
    Date of Patent: November 2, 2004
    Assignee: Applied Materials Inc.
    Inventors: Zhong Qiang Hua, Dong Qing Li, Zhengquan Tan, Zhuang Li, Michael Chiu Kwan, Bruno Geoffrion, Padmanabhan Krishnaraj
  • Publication number: 20040126952
    Abstract: The present invention is directed to improving defect performance in semiconductor processing systems. In specific embodiments, an apparatus for processing semiconductor substrates comprises a chamber defining a processing region therein, and a substrate support disposed in the chamber to support a semiconductor substrate. At least one nozzle extends into the chamber to introduce a process gas into the chamber through a nozzle opening. The apparatus comprises at least one heat shield, each of which is disposed around at least a portion of one of the at least one nozzle. The heat shield has an extension which projects distally of the nozzle opening of the nozzle and which includes a heat shield opening for the process gas to flow therethrough from the nozzle opening. The heat shield decreases the temperature of nozzle in the processing chamber for introducing process gases therein to reduce particles.
    Type: Application
    Filed: July 28, 2003
    Publication date: July 1, 2004
    Applicant: APPLIED MATERIALS, INC.
    Inventors: Sudhir Gondhalekar, Padmanabhan Krishnaraj, Tom K. Cho, Muhammad Rasheed, Hemant Mungekar, Thanh N. Pham, Zhong Qiang Hua
  • Publication number: 20040115898
    Abstract: A method of depositing an insulating film over a substrate having a gap formed between two adjacent raised features. The method includes depositing one portion of the insulating film over the substrate and in the gap using a high density plasma process that has simultaneous deposition and sputtering components and depositing another portion of the insulating film over the substrate and in the gap using an atomic layer deposition process. In some embodiments the portion of the film deposited by an atomic layer deposition process is deposited over the portion of the film deposited using a high density plasma CVD technique. In other embodiments, the portion of the film deposited by a high density plasma CVD process is deposited over the portion of the film deposited using an atomic layer deposition process.
    Type: Application
    Filed: December 13, 2002
    Publication date: June 17, 2004
    Applicant: Applied Materials, Inc.
    Inventors: Farhad K. Moghadam, Michael S. Cox, Padmanabhan Krishnaraj, Thanh N. Pham, Zhenjiang Cui
  • Patent number: 6715496
    Abstract: A method and apparatus for cleaning a semiconductor wafer processing system comprising a turbomolecular pump. In one embodiment, the invention may be reduced to practice by first supplying a cleaning agent to a chamber; pumping the cleaning agent from the chamber through an the exhaust port; at least partially opening a gate valve; and drawing at least a portion of the cleaning agent through the gate valve and into the turbomolecular pump.
    Type: Grant
    Filed: April 3, 2003
    Date of Patent: April 6, 2004
    Assignee: Applied Materials Inc.
    Inventors: Michael Chiu Kwan, Alan W. Collins, Jalel Hamila, Padmanabhan Krishnaraj, Zhengquan Tan
  • Publication number: 20030203637
    Abstract: A method of depositing a high density plasma silicon oxide layer having improved gapfill capabilities. In one embodiment the method includes flowing a process gas consisting of a silicon-containing source, an oxygen-containing source and helium into a substrate processing chamber and forming a plasma from the process gas. The ratio of the flow rate of the helium with respect to the combined flow rate of the silicon source and oxygen source is between 0.5:1 and 3.0:1 inclusive. In one particular embodiment, the process gas consists of monosilane (SiH4), molecular oxygen (O2) and helium.
    Type: Application
    Filed: April 30, 2002
    Publication date: October 30, 2003
    Applicant: Applied Materials, Inc.
    Inventors: Zhong Qiang Hua, Dong Qing Li, Zhengquan Tan, Zhuang Li, Michael Chiu Kwan, Bruno Geoffrion, Padmanabhan Krishnaraj
  • Patent number: 6635144
    Abstract: Apparatus for processing semiconductor wafers includes a processing chamber, a chuck within the chamber for supporting a wafer during processing, a fiberoptic cable having a first end positioned at the surface of the chuck, and an optical pyrometer connected to a second end of the cable. The optical pyrometer measures the temperature of a wafer during processing and measures in situ temperature of plasma-excited cleaning gas introduced into the chamber during subsequent cleaning from walls thereof of unwanted solid deposits within the chamber. The pyrometer is connected to a computer which controls the flow of cleaning gases. When the temperature of the plasma-excited gas reaches a steady-state value the computer stops the flow of cleaning gases into the chamber and thereby stops the cleaning operation.
    Type: Grant
    Filed: April 11, 2001
    Date of Patent: October 21, 2003
    Assignee: Applied Materials, Inc
    Inventors: Zhenjiang Cui, Padmanabhan Krishnaraj, Shamouil Shamouilian
  • Patent number: 6633076
    Abstract: Methods and apparatus of the present invention deposit fluorinated silicate glass (FSG) in such a manner that it strongly adheres to an overlying or underlying barrier layer or etch stop layer, and has a lower dielectric constant, among other benefits. In one embodiment, silicon tetrafluoride (SiF4), oxygen (O2), and argon (Ar) are used as the reactant gases, with the ratio of oxygen to silicon controlled to be at between about 2:1 to 6:1. Such O2 levels help reduce the amount of degradation of ceramic chamber components otherwise caused by the elimination of silane from the process recipe.
    Type: Grant
    Filed: October 30, 2002
    Date of Patent: October 14, 2003
    Assignee: Applied Materials, Inc.
    Inventors: Padmanabhan Krishnaraj, Robert Duncan, Joseph D'Souza, Alan W. Collins, Nasreen Chopra, Kimberly Branshaw
  • Publication number: 20030164224
    Abstract: A method and apparatus for cleaning a semiconductor wafer processing system comprising a turbomolecular pump. In one embodiment, the invention may be reduced to practice by first supplying a cleaning agent to a chamber; pumping the cleaning agent from the chamber through an the exhaust port; at least partially opening a gate valve; and drawing at least a portion of the cleaning agent through the gate valve and into the turbomolecular pump.
    Type: Application
    Filed: April 3, 2003
    Publication date: September 4, 2003
    Inventors: Michael Chiu Kwan, Alan W. Collins, Jalel Hamila, Padmanabhan Krishnaraj, Zhengquan Tan
  • Publication number: 20030136332
    Abstract: A continuous in situ process of deposition, etching, and deposition is provided for forming a film on a substrate using a plasma process. The etch-back may be performed without separate plasma activation of the etchant gas. The sequence of deposition, etching, and deposition permits features with high aspect ratios to be filled, while the continuity of the process results in improved uniformity.
    Type: Application
    Filed: January 24, 2002
    Publication date: July 24, 2003
    Applicant: APPLIED MATERIALS INC., A Delaware corporation
    Inventors: Padmanabhan Krishnaraj, Pavel Ionov, Canfeng Lai, Michael Santiago Cox, Shamouil Shamouilian
  • Patent number: 6596123
    Abstract: A method and apparatus for cleaning a semiconductor wafer processing system comprising a turbomolecular pump. In one embodiment, the invention may be reduced to practice by first supplying a cleaning agent to a chamber; pumping the cleaning agent from the chamber through an the exhaust port; at least partially opening a gate valve; and drawing at least a portion of the cleaning agent through the gate valve and into the turbomolecular pump.
    Type: Grant
    Filed: January 28, 2000
    Date of Patent: July 22, 2003
    Assignee: Applied Materials, Inc.
    Inventors: Michael Chiu Kwan, Alan W. Collins, Jalel Hamila, Padmanabhan Krishnaraj, Zhengquan Tan
  • Publication number: 20030064556
    Abstract: Methods and apparatus of the present invention deposit fluorinated silicate glass (FSG) in such a manner that it strongly adheres to an overlying or underlying barrier layer or etch stop layer, and has a lower dielectric constant, among other benefits. In one embodiment, silicon tetrafluoride (SiF4), oxygen (O2), and argon (Ar) are used as the reactant gases, with the ratio of oxygen to silicon controlled to be at between about 2:1 to 6:1. Such O2 levels help reduce the amount of degradation of ceramic chamber components otherwise caused by the elimination of silane from the process recipe.
    Type: Application
    Filed: October 30, 2002
    Publication date: April 3, 2003
    Applicant: Applied Materials, Inc.
    Inventors: Padmanabhan Krishnaraj, Robert Duncan, Joseph D'Souza, Alan W. Collins, Nasreen Chopra, Kimberly Branshaw