Patents by Inventor Ramkumar Subramanian

Ramkumar Subramanian 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: 6654660
    Abstract: One aspect of the present invention relates to a system and method for controlling thermal expansion on an EUV mask during EUV photolithography. The system includes an EUV photolithography system for irradiating one or more layers of a wafer through one or more gratings of a patterned EUV mask, whereby heat accumulates on at least a portion of the patterned EUV mask during the irradiation of the one or more layers of the wafer; an EUV mask inspection system for monitoring the one or more gratings on the mask to detect expansion therein, the inspection system producing data relating to the mask; and a temperature control system operatively coupled to the inspection system for making adjustments to the EUV photolithography system in order to compensate for the detected expansion on the mask. The method involves employing feedback and feed forward control to optimize the current and future EUV photolithography processes.
    Type: Grant
    Filed: November 4, 2002
    Date of Patent: November 25, 2003
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Bhanwar Singh, Christopher F. Lyons, Bharath Rangarajan, Khoi A. Phan, Ramkumar Subramanian
  • Patent number: 6653221
    Abstract: An SOI device structure is provided which facilitates mitigation of charge build up caused by floating body effects. A ground contact is formed from a top insulating layer to a bottom silicon layer. The ground contact extends through the insulating layer, a stop layer, an isolation region and an oxide layer to the bottom silicon layer. The ground contact is fabricated along with the formation of local interconnects.
    Type: Grant
    Filed: April 2, 2001
    Date of Patent: November 25, 2003
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Ramkumar Subramanian, Bharath Rangarajan, Bhanwar Singh
  • Patent number: 6650422
    Abstract: The present invention is directed to a method and a system for non-destructively, efficiently and accurately detecting asymmetry in the profile of a feature formed on a wafer during the process of semiconductor fabrication. The method encompasses directing a beam of light or radiation at a feature and detecting a reflected beam associated therewith. Data associated with the reflected beam is correlated with data associated with known feature profiles to ascertain profile characteristics associated with the feature of interest. Using the profile characteristics, an asymmetry of the feature is determined which is then used to generate feedback or feedforward process control data to compensate for or correct such asymmetry in subsequent processing.
    Type: Grant
    Filed: March 26, 2001
    Date of Patent: November 18, 2003
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Bhanwar Singh, Michael K. Templeton, Bharath Rangarajan, Ramkumar Subramanian
  • Patent number: 6643604
    Abstract: A system for regulating heating temperature of a material is provided. The material may be a photoresist, a top or bottom anti-reflective coating, a low K dielectric material, SOG or other spin-on material, for example. The system includes a plurality of lamps and optical fibers, each optical fiber directing radiation to and heating a respective portions of a bakeplate on which the material is to be placed. In one embodiment, the temperature at various locations on the material placed on the bakeplate is determined and the heating rates are controlled in response to those measurements. In another aspect of the invention, the temperature at various portions of the bakeplate is determined and controlled. In this latter aspect, uniform heating of the material is a consequence of uniform bakeplate temperature.
    Type: Grant
    Filed: June 30, 2000
    Date of Patent: November 4, 2003
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Ramkumar Subramanian, Michael K. Templeton, Bharath Rangarajan
  • Patent number: 6641963
    Abstract: A system for regulating temperature of a post exposure baking process is provided. The system includes one or more light sources, each light source directing light to one or more gratings being baked and hardened on a wafer. Light reflected from the gratings is collected by a measuring system, which processes the collected light. Light passing through the gratings may similarly be collected by the measuring system, which processes the collected light. The collected light is indicative of the baking and hardening of the respective portions of the wafer. The measuring system provides baking and hardening related data to a processor that determines the baking and hardening of the respective portions of the wafer. The system also includes a plurality of temperature controlling devices, each such device corresponds to a respective portion of the wafer and provides for the heating and/or cooling thereof.
    Type: Grant
    Filed: April 30, 2001
    Date of Patent: November 4, 2003
    Assignee: Advanced Micro Devices, INC
    Inventors: Bharath Rangarajan, Michael K. Templeton, Bhanwar Singh, Ramkumar Subramanian
  • Patent number: 6634805
    Abstract: A system and method is provided for applying a developer to a photoresist material wafer disposed on a semiconductor substrate. The developer system and method employ a developer plate having a plurality of a apertures for dispensing developer. Preferably, the developer plate has a bottom surface with a shape that is similar to the wafer. The developer plate is disposed above the wafer and substantially and/or completely surrounds the top surface of the wafer during application of the developer. A small gap is formed between the wafer and the bottom surface of the developer plate. The wafer and the developer plate form a parallel plate pair, such that the gap can be made small enough so that the developer fluid quickly fills the gap. The developer plate is disposed in very close proximity with respect to the wafer, such that the developer is squeezed between the two plates thereby spreading evenly the developer over the wafer.
    Type: Grant
    Filed: October 10, 2001
    Date of Patent: October 21, 2003
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Michael K. Templeton, Khoi A. Phan, Bharath Rangarajan, Bryan K. Choo, Ramkumar Subramanian
  • Patent number: 6632283
    Abstract: The present invention relates to illuminating an interior portion of a processing chamber in a semiconductor processing system. A light emitting diode is located in the chamber to illuminate the interior of the chamber to facilitate viewing the interior of the chamber.
    Type: Grant
    Filed: June 9, 2000
    Date of Patent: October 14, 2003
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Bhanwar Singh, Bharath Rangarajan, Khoi A. Phan, Bryan K. Choo, Ramkumar Subramanian
  • Patent number: 6632707
    Abstract: A method for forming a metal interconnect structure in a semiconductor device with the elimination of via poisoning during trench mask formation employs a CVD organic BARC that isolates the low k dielectric film. The CVD organic BARC is deposited over the low k dielectric film and in the via hole. Once the trench mask has been formed on the CVD organic BARC, the CVD organic BARC may be removed in the same process as the photoresist of the trench mask layer. A properly formed trench will have been created since the via poisoning and resist scumming were substantially eliminated by the presence of the CVD organic BARC.
    Type: Grant
    Filed: January 29, 2002
    Date of Patent: October 14, 2003
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Fei Wang, Lynne A. Okada, Ramkumar Subramanian, James K. Kai, Calvin T. Gabriel, Lu You
  • Patent number: 6633392
    Abstract: One aspect of the present invention relates to a method to facilitate formation of an oxide portion of an anti-reflective layer on a substrate. The method involves the steps of forming an oxidized portion of an anti-reflective coating over an anti-reflective layer disposed on the substrate; reflecting a beam of x-ray radiation at the oxidized portion; generating a measurement signal based on the reflected portion of the light beam; and determining a thickness of the oxidized portion based on the measurement signal while the oxidized portion is being formed at the substrate.
    Type: Grant
    Filed: January 17, 2002
    Date of Patent: October 14, 2003
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Bhanwar Singh, Arvind Halliyal, Ramkumar Subramanian
  • Publication number: 20030188829
    Abstract: A system for characterizing a chemical mechanical polishing process is provided. The system includes a wafer that has a metal, polysilicon, and/or dielectric layer and/or substrate and electrical resistance member(s) and/or electrical resistance entities located in and/or on the metal, polysilicon and/or dielectric layer and/or substrate. The system also includes a electrical resistance monitoring system that can read the wafer electrical resistance(s) from the electrical resistance member(s) and/or electrical resistance entities and that can determine wafer stress(es) based upon the electrical resistance(s) to characterize the chemical mechanical polishing process. Such characterization includes producing information concerning relationships between wafer electrical resistance(s) and polishing rate, polishing uniformity and introduction of defects during polishing. Such relationships are correlated with wafer electrical resistance(s) (e.g.
    Type: Application
    Filed: December 27, 2001
    Publication date: October 9, 2003
    Inventors: Bharath Rangarajan, Steven C. Avanzino, Ramkumar Subramanian, Bhanwar Singh
  • Patent number: 6629786
    Abstract: A system for regulating the time and temperature of a development process is provided. The system includes one or more light sources, each light source directing light to one or more gratings being developed on a wafer. Light reflected from the gratings is collected by a measuring system, which processes the collected light. Light passing through the gratings may similarly be collected by the measuring system, which processes the collected light. The collected light is indicative of the progress of development of the respective portions of the wafer. The measuring system provides progress of development related data to a processor that determines the progress of development of the respective portions of the wafer. The system also includes a plurality of heating devices, each heating device corresponds to a respective portion of the developer and provides for the heating thereof. The processor selectively controls the heating devices so as to regulate temperature of the respective portions of the wafer.
    Type: Grant
    Filed: April 30, 2001
    Date of Patent: October 7, 2003
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Bharath Rangarajan, Michael K. Templeton, Bhanwar Singh, Ramkumar Subramanian
  • Patent number: 6630361
    Abstract: A system for regulating a gaseous phase chemical trim process is provided. The system includes one or more light sources, each light source directing light to one or more features and/or gratings on a wafer. Light reflected from the features and/or gratings is collected by a measuring system, which processes the collected light. The collected light is indicative of the dimensions achieved at respective portions of the wafer. The measuring system provides trimming related data to a processor that determines the acceptability of the trimming of the respective portions of the wafer. The system also includes one or more trimming devices, each such device corresponding to a portion of the wafer and providing for the trimming thereof. The processor selectively controls the trimming devices to regulate trimming of the portions of the wafer.
    Type: Grant
    Filed: June 28, 2001
    Date of Patent: October 7, 2003
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Bhanwar Singh, Bharath Rangarajan, Michael K. Templeton, Ramkumar Subramanian, Cristina Cheung
  • Patent number: 6622547
    Abstract: A system and method for evaluating optical proximity corrected (OPC) designs is provided. The system includes an AFM measurement system for performing measurements relating to a segment of a feature pattern corresponding to a predetermined OPC mask feature. The measurement system is configured to determine a first image for the segment of the printed feature based upon the measurements. The measurement system compares the first image with another image corresponding to different OPC design to evaluate performance characteristics of the respective OPC designs.
    Type: Grant
    Filed: July 17, 2002
    Date of Patent: September 23, 2003
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Khoi Phan, Ramkumar Subramanian, Bhanwar Singh
  • Patent number: 6624642
    Abstract: Disclosed is a wafer containing a semiconductor substrate, at least one metal layer formed over the semiconductor substrate, and at least one electrical sensor embedded at least one of on and in the wafer to facilitate real time monitoring of the metal layer as it progresses through a subtractive metallization process. The system contains a wafer comprising at least one metal layer formed on a semiconductor substrate, at least one electrical sensor in contact with the wafer and operable to detect and transmit electrical activity associated with the wafer, and an electrical measurement station operable to process electrical activity detected and received from the electrical sensor for monitoring a subtractive metallization process in real-time.
    Type: Grant
    Filed: December 10, 2001
    Date of Patent: September 23, 2003
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Christopher F. Lyons, Ramkumar Subramanian, Steven C. Avanzino
  • Patent number: 6617087
    Abstract: The present invention provides a system and process for controlling the application of patterned resist coatings in an integrated circuit manufacturing process that employs multiple reticle patterns. One aspect of the invention relates to obtaining scatterometry measurements from a patterned resist and using the measurements to determine whether the correct reticle pattern was employed in forming the patterned resist. According to another aspect of the invention, the reticles are provided with grating patterns in addition to reticle patterns, whereby when the reticles are printed, gratings are formed in the resist. The gratings can be used, with scatterometry, to identify the reticle pattern. The reticles can be configured so that the gratings form in a non-functional portion of a wafer, such as a portion along a score line. Where it is, determined that the correct reticle pattern was not used, corrective action can be taken such as stripping the resist and reprocessing the affected wafers.
    Type: Grant
    Filed: June 27, 2001
    Date of Patent: September 9, 2003
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Bharath Rangarajan, Bhanwar Singh, Ramkumar Subramanian
  • Patent number: 6613500
    Abstract: One aspect of the present invention relates to a method for reducing resist residue defects on a wafer structure. The method involves providing a semiconductor structure having a photoresist, the photoresist comprising open areas and circuit areas thereon; irradiating the open areas and circuit areas through a first photomask with a first energy dose to effect an image-wise pattern in the photoresist; irradiating the open areas of the photoresist through a second photomask with a second energy dose; and developing the photoresist.
    Type: Grant
    Filed: April 2, 2001
    Date of Patent: September 2, 2003
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Khoi A. Phan, Bhanwar Singh, Ramkumar Subramanian, Michael K. Templeton, Jeff Erhardt
  • Patent number: 6605546
    Abstract: A method for forming a semiconductor device comprises forming a first layer over a semiconductor substrate. At least one hole is formed through the first layer. A bottom anti-reflective coating (BARC) layer is formed in the at least one hole. A first heating is performed to heat the BARC layer to a flow temperature. A second heating is performed to heat the BARC layer to a hardening temperature so that the BARC layer hardens, wherein the hardening temperature is greater than the flow temperature. An etch is performed to form a trench in the first layer and over the at least one hole, wherein the hardened BARC layer in the at least one hole acts as an etch resistant layer during the etch. As an alternative to the second heating step, the BARC may be simply hardened. The first and second heating may be performed within a heating chamber without removing the semiconductor substrate.
    Type: Grant
    Filed: July 11, 2001
    Date of Patent: August 12, 2003
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Ramkumar Subramanian, Wolfram Grundke, Bhanwar Singh, Christopher F. Lyons, Marina V. Plat
  • Patent number: 6605413
    Abstract: There is provided a method for forming a photoresist layer for photolithographic applications which has increased structural strength. The photoresist layer is exposed through a mask and developed. The photoresist layer is then reacted with a stabilizer agent to change its material properties before the photoresist layer is dried. Also provided are a semiconductor fabrication method employing a stabilizer-treated photoresist and a composition for a photoresist that strengthens when exposed to a stabilizer agent.
    Type: Grant
    Filed: August 29, 2002
    Date of Patent: August 12, 2003
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Christopher F. Lyons, Ramkumar Subramanian
  • Patent number: 6605855
    Abstract: The present invention relates to a method for fabricating interconnecting lines and vias in a layer of insulating material. A via is formed in the layer of insulating material. A protective material is formed so as to be conformal to at least edges and sidewalls of the via, the protective material facilitating shielding of at least the edges and sidewalls of the via from a trench etch step. The trench etch step is performed to form a trench opening in the insulating material. The via and trench are filled with a conductive metal.
    Type: Grant
    Filed: August 30, 2000
    Date of Patent: August 12, 2003
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Bhanwar Singh, Michael K. Templeton, Bharath Rangarajan, Christopher F. Lyons, Sanjay K. Yedur, Ramkumar Subramanian
  • Patent number: 6602727
    Abstract: A system for regulating an exposure condition determining process is provided. The system includes one or more light sources, each light source directing light to one or more gratings exposed on one or more portions of a wafer. Light reflected from the gratings is collected by a measuring system, which processes the collected light. Light passing through the gratings may similarly be collected by the measuring system, which processes the collected light. The collected light is analyzed to determine whether exposure conditions should be adapted prior to exposing a pattern on the wafer. The measuring system provides grating signature data to a processor that determines the acceptability of the exposure condition by comparing determined signatures to desired signatures. The system also includes an exposing system that can be controlled to change exposure conditions. The processor selectively controls the exposing system, via the exposer driving system, to adapt such exposure conditions.
    Type: Grant
    Filed: April 26, 2002
    Date of Patent: August 5, 2003
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Bharath Rangarajan, Bhanwar Singh, Ramkumar Subramanian