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: 6934032
    Abstract: A system and methodology for monitoring and/or controlling a semiconductor fabrication process is disclosed. Scatterometry and/or ellipsometry based techniques can be employed to facilitate providing measurement signals during a damascene phase of the fabrication process. The thickness of layers etched away during the process can be monitored and one or more fabrication components and/or operating parameters associated with the fabrication component(s) can be adjusted in response to the measurements to achieve desired results, such as to mitigate the formation of copper oxide during etching of a copper layer, for example.
    Type: Grant
    Filed: September 30, 2002
    Date of Patent: August 23, 2005
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Ramkumar Subramanian, Steven C. Avanzino, Bharath Rangarajan, Bhanwar Singh
  • Patent number: 6931618
    Abstract: A system for selectively generating and feeding forward reticle fabrication data is provided. The system includes components for fabricating a reticle and a control system operatively connected to the fabricating components, where the control system can control the operation of the fabricating components. The control system bases its control of the fabricating components, at least in part, on feed forward control information generated by a processor that analyzes scatterometry based reticle fabrication data gathered from measurement components. The scatterometry data is compared to data stored in a signature data store that facilitates analyzing gathered scatterometry signatures to produce feed forward control information that can be employed to manipulate subsequent reticle fabrication processes and/or apparatus.
    Type: Grant
    Filed: January 16, 2002
    Date of Patent: August 16, 2005
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Cyrus E. Tabery, Bharath Rangarajan, Bhanwar Singh, Ramkumar Subramanian
  • Publication number: 20050164133
    Abstract: The invention provides systems and processes that form the inverse (photographic negative) of a patterned first coating. The patterned first coating is usually provided by a resist. After the first coating is patterned, a coating of a second material is provided thereover. The uppermost layer of the second coating is removed, where appropriate, to expose the patterned first coating. The patterned first coating is subsequently removed, leaving the second coating material in the form of a pattern that is the inverse pattern of the first coating pattern. The process may be repeated with a third coating material to reproduce the pattern of the first coating in a different material. Prior to applying the second coating, the patterned first coating may be trimmed by etching, thereby reducing the feature size and producing sublithographic features. In addition to providing sublithographic features, the invention gives a simple, efficient, and high fidelity method of obtaining inverse coating patterns.
    Type: Application
    Filed: March 22, 2005
    Publication date: July 28, 2005
    Inventors: Bharath Rangarajan, Michael Templeton, Ramkumar Subramanian
  • Patent number: 6915177
    Abstract: The present invention provides systems and methods that facilitate performing fabrication process. Critical parameters are valued collectively as a quality matrix, which weights respective parameters according to their importance to one or more design goals. The critical parameters are weighted by coefficients according to information such as, product design, simulation, test results, yield data, electrical data and the like. The invention then can develop a quality index which is a composite “score” of the current fabrication process. A control system can then do comparisons of the quality index with design specifications in order to determine if the current fabrication process is acceptable. If the process is unacceptable, test parameters can be modified for ongoing processes and the process can be re-worked and re-performed for completed processes. As such, respective layers of a device can be customized for different specifications and quality index depending on product designs and yields.
    Type: Grant
    Filed: September 30, 2002
    Date of Patent: July 5, 2005
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Khoi A. Phan, Bhanwar Singh, Bharath Rangarajan, Ramkumar Subramanian
  • Patent number: 6912438
    Abstract: A system and methodology are disclosed for monitoring and controlling a semiconductor fabrication process. Measurements are taken in accordance with scatterometry based techniques of repeating in circuit structures that evolve on a wafer as the wafer undergoes the fabrication process. The measurements can be employed to generate feed forward and/or feedback control data that can utilized to selectively adjust one or more fabrication components and/or operating parameters associated therewith to adapt the fabrication process. Additionally, the measurements can be employed in determining whether to discard the wafer or portions thereof based on a cost benefit analysis, for example. Directly measuring in circuit structures mitigates sacrificing valuable chip real estate as test grating structures may not need to be formed within the wafer, and also facilitates control over the elements that actually affect resulting chip performance.
    Type: Grant
    Filed: October 21, 2002
    Date of Patent: June 28, 2005
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Bryan K. Choo, Bhanwar Singh, Ramkumar Subramanian, Bharath Rangarajan
  • Patent number: 6905950
    Abstract: The present invention involves a method for fabricating interconnecting lines and vias. According to the invention, copper is grown within the openings in a patterned coating. The patterned coating can be a resist coating or a dielectric coating. Either type of coating can be formed over a copper seed layer, whereby the seed layer is exposed within the pattern gaps. The copper seed layer can also be provided within the pattern gaps after patterning. Copper features are grown within the pattern gaps by plating. Where the patterned coating is a resist, the resist is stripped leaving the copper features in the inverse pattern image. The copper features can be coated with a diffusion barrier layer and a dielectric. The dielectric is polished to leave the dielectric filling the spaces between copper features. The invention provides copper lines and vias without the need for a dielectric or metal etching step.
    Type: Grant
    Filed: June 27, 2001
    Date of Patent: June 14, 2005
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Ramkumar Subramanian, Michael K. Templeton, Bhanwar Singh, Bharath Rangarajan
  • Publication number: 20050121738
    Abstract: An apparatus and a method of fabricating a semiconductor device including the steps of forming a gate dielectric layer on a semiconductor substrate; forming a gate electrode over the gate dielectric layer wherein the gate electrode defines a channel interposed between source/drain regions formed within an active region of the semiconductor substrate; and forming contact etch resistant spacers on sidewalls of the gate electrode and sidewalls of the gate dielectric layer, the contact etch resistant spacers are of a non-silicon oxide and a non-nitride material.
    Type: Application
    Filed: December 3, 2003
    Publication date: June 9, 2005
    Inventors: Calvin Gabriel, Christopher Lyons, Marina Plat, Ramkumar Subramanian
  • Patent number: 6900124
    Abstract: A method of forming a contact in a flash memory device is disclosed. The method increases the depth of focus margin and the overlay margin between the contact and the stacked gate layers. A plurality of stacked gate layers are formed on a semiconductor substrate, wherein each stacked gate layer extends in a predefined direction and is substantially parallel to other stacked gate layers. An interlayer insulating layer is deposited over the plurality of stacked gate layers, and a contact hole is patterned between a first stacked gate layer of the plurality of stacked gate layers and a second stacked gate layer of the plurality of stacked gate layers. The contact hole is formed in an elongated shape, wherein a major axis of the contact hole is substantially parallel to the stacked gate layers. A conductive layer is deposited in the contact hole and excess conductive material is removed.
    Type: Grant
    Filed: September 3, 2003
    Date of Patent: May 31, 2005
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Hung-eil Kim, Anna Minvielle, Christopher F. Lyons, Marina V. Plat, Ramkumar Subramanian
  • Patent number: 6889763
    Abstract: Resist coated wafers are rapidly and uniformly cooled by a fluid that has been cooled through the Joule-Thompson effect. Fluid from a high pressure reservoir is vented into a chamber that contains the substrates. By varying the pressure difference between the reservoir and the chamber, the temperature of the cooling fluid entering the chamber can be controlled. By also controlling the flow rate through the chamber, the average temperature difference between the fluid in the chamber and the substrates may be limited, whereby more uniform cooling is obtained. While the chamber pressure is lower than that in the high pressure reservoir, the chamber pressure may still be substantially greater than atmospheric. An elevated chamber pressure raises the specific heat and residence time of the fluid in the chamber, which also promotes uniform cooling.
    Type: Grant
    Filed: November 6, 2000
    Date of Patent: May 10, 2005
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Ramkumar Subramanian, Bharath Rangarajan, Michael K. Templeton
  • Publication number: 20050092983
    Abstract: Systems and methodologies are disclosed for increasing the number of memory cells associated with a lithographic feature. The systems comprise memory elements that are formed on the sidewalls of the lithographic feature by employing various depositing and etching processes. The side wall memory cells can have a bit line of the wafer as the first electrode and operate with a second formed electrode to activate a portion of an organic matter that is formed there between.
    Type: Application
    Filed: November 3, 2003
    Publication date: May 5, 2005
    Inventors: Christopher Lyons, Mark Chang, Sergey Lopatin, Ramkumar Subramanian, Patrick Cheung, Minh Ngo, Jane Oglesby
  • Patent number: 6878560
    Abstract: A system comprised of a plurality of fabs that are operatively coupled and share data from a common framework for correlating production. The fabs can be coupled via Internet, cellular, optical, landline, microwave and satellite communication means and the like. Data can be transferred to and/or received from a central, integrated correlating entity or from several distributed correlating entities. The fabs send and receive correlating data that relates to production information such as tolerances, critical dimensions, geometry and the like. The correlating entity(s) has the capability to increase production by performing probabilistic computations on the received correlating data and utilizing the resulting information to maintain correlating parameters at remote locations. The computations performed can include such calculations as Bayesian inferencing and the like. The system inherently precludes the necessity for physically transporting parametric test entities between different fab or tooling locations.
    Type: Grant
    Filed: November 22, 2002
    Date of Patent: April 12, 2005
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Bharath Rangarajan, Bhanwar Singh, Ramkumar Subramanian
  • Patent number: 6879051
    Abstract: One aspect of the present invention relates to a method to facilitate formation of seed layer portions on sidewall surfaces of a trench formed in a substrate. The method involves the steps of forming a conformal seed layer over a barrier layer disposed conformal to a trench, wherein the trench is formed in the substrate; reflecting a light beam of x-ray radiation at the seed layer sidewall portions; generating a measurement signal based on the reflected portion of the light beam; and determining a thickness of the sidewall portions based on the measurement signal while the sidewall portions are being formed over the trench.
    Type: Grant
    Filed: January 16, 2002
    Date of Patent: April 12, 2005
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Bhanwar Singh, Michael K. Templeton, Bharath Rangarajan, Ramkumar Subramanian
  • Patent number: 6878622
    Abstract: A method is provided for manufacturing a semiconductor device on a semiconductor substrate using a dielectric as a bottom anti-reflective coating for formation of a photoresist contact opening which is used to enlarge the Final Inspection Critical Dimension (FICD) of the conductive contact. A high selectivity etch is used to form a tapered contact.
    Type: Grant
    Filed: July 1, 2003
    Date of Patent: April 12, 2005
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Wenge Yang, Ramkumar Subramanian, Fei Wang, Lewis Shen
  • Patent number: 6879406
    Abstract: One aspect of the present invention relates to a system and method for controlling an EUV mask fabrication process using a scatterometer. The system includes an EUV mask fabrication system comprising a translucent substrate having one or more layers of reflective material formed thereon and a patterned photoresist layer as the uppermost layer, a mask inspection system operatively connected to the mask fabrication system for examining the layers as they are being etched and developed by the mask fabrication system and generating data related thereto, and an EUV mask fabrication control system coupled to the mask inspection system for receiving data from the inspection system in order to regulate the mask fabrication system to facilitate obtaining desired critical dimensions. The method involves monitoring the etching of the features, generating data related to the features, and relaying the data to a control system to optimize the EUV mask fabrication process.
    Type: Grant
    Filed: October 1, 2003
    Date of Patent: April 12, 2005
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Bharath Rangarajan, Ramkumar Subramanian, Bhanwar Singh
  • Patent number: 6878961
    Abstract: A method of making organic memory cells made of two electrodes with a controllably conductive media between the two electrodes is disclosed. The controllably conductive media contains an organic semiconductor layer that contains a photosensitive compound. The organic semiconductor layer is formed into memory cells using patterning techniques.
    Type: Grant
    Filed: September 28, 2004
    Date of Patent: April 12, 2005
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Christopher F. Lyons, Ramkumar Subramanian, Mark S. Chang
  • Patent number: 6869888
    Abstract: A method for forming a semiconductor device is described. The method 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. The BARC layer is exposed to an electron beam (e-beam) so that the BARC layer reaches a flow temperature in the at least one hole. An etch is performed to form a trench in the first layer and over the at least one hole, wherein the BARC layer in the at least one hole acts as an etch resistant layer during the etch.
    Type: Grant
    Filed: July 11, 2001
    Date of Patent: March 22, 2005
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Marina V. Plat, Ramkumar Subramanian, Christopher F. Lyons, Bhanwar Singh
  • Publication number: 20050045877
    Abstract: A method of making organic memory cells made of two electrodes with a controllably conductive media between the two electrodes is disclosed. The controllably conductive media contains an organic semiconductor layer that contains a photosensitive compound. The organic semiconductor layer is formed into memory cells using patterning techniques.
    Type: Application
    Filed: September 28, 2004
    Publication date: March 3, 2005
    Inventors: Christopher Lyons, Ramkumar Subramanian, Mark Chang
  • Patent number: 6849469
    Abstract: Real-time analysis and control of a semiconductor silicidation process. The architecture includes system and methods for monitor and control of a silicidation process during rapid thermal anneal. An FTIR system analyzes selected and/or random regions where silicidation is occurring, and signals the process control system to control the process according to the status of the analyzed silicide formations.
    Type: Grant
    Filed: October 1, 2003
    Date of Patent: February 1, 2005
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Ciby Thomas Thuruthiyil, Bhanwar Singh, Ramkumar Subramanian
  • Patent number: 6846749
    Abstract: A method for forming a metal interconnect comprises exposing a dielectric layer to an etch chemistry containing nitrogen-containing compound such as NH3, NF3 or N2O. The nitrogen-containing compound provides selectivity and/or profile control comparable to that provided by N2, while avoiding poisoning of photoresist by embedded N2.
    Type: Grant
    Filed: June 25, 2001
    Date of Patent: January 25, 2005
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Calvin T. Gabriel, Lynne A. Okada, Ramkumar Subramanian
  • Patent number: 6845345
    Abstract: A system for analyzing diagnostic information associated with a spin track is provided. The system includes one or more analysis systems that collect diagnostic information from one or more spin tracks. The system further includes one or more maintenance systems that schedule routine and/or special maintenance based on analysis of the diagnostic information. An alternative aspect of the system further includes one or more control information systems that generate of feedback control information employed in adapting the processes performed by the spin track.
    Type: Grant
    Filed: February 6, 2001
    Date of Patent: January 18, 2005
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Bhanwar Singh, Michael K. Templeton, Ramkumar Subramanian