Patents by Inventor Balasubramanian S. Haran

Balasubramanian S. Haran 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: 20130102130
    Abstract: A fin field-effect-transistor fabricated by forming a dummy fin structure on a semiconductor substrate. A dielectric layer is formed on the semiconductor substrate. The dielectric layer surrounds the dummy fin structure. The dummy fin structure is removed to form a cavity within the dielectric layer. The cavity exposes a portion of the semiconductor substrate thereby forming an exposed portion of the semiconductor substrate within the cavity. A dopant is implanted into the exposed portion of the semiconductor substrate within the cavity thereby creating a dopant implanted exposed portion of the semiconductor substrate within the cavity. A semiconductor layer is epitaxially grown within the cavity atop the dopant implanted exposed portion of the semiconductor substrate.
    Type: Application
    Filed: October 20, 2011
    Publication date: April 25, 2013
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Kangguo CHENG, Balasubramanian S. HARAN, Shom PONOTH, Theodorus E. STANDAERT, Tenko YAMASHITA
  • Patent number: 8420459
    Abstract: A fin field-effect-transistor fabricated by forming a dummy fin structure on a semiconductor substrate. A dielectric layer is formed on the semiconductor substrate. The dielectric layer surrounds the dummy fin structure. The dummy fin structure is removed to form a cavity within the dielectric layer. The cavity exposes a portion of the semiconductor substrate thereby forming an exposed portion of the semiconductor substrate within the cavity. A dopant is implanted into the exposed portion of the semiconductor substrate within the cavity thereby creating a dopant implanted exposed portion of the semiconductor substrate within the cavity. A semiconductor layer is epitaxially grown within the cavity atop the dopant implanted exposed portion of the semiconductor substrate.
    Type: Grant
    Filed: October 20, 2011
    Date of Patent: April 16, 2013
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Balasubramanian S. Haran, Shom Ponoth, Theodorus E. Standaert, Tenko Yamashita
  • Publication number: 20130082308
    Abstract: Transistor devices and methods of their fabrication are disclosed. In one method, a dummy gate structure is formed on a substrate. Bottom portions of the dummy gate structure are undercut. In addition, stair-shaped, raised source and drain regions are formed on the substrate and within at least one undercut formed by the undercutting. The dummy gate structure is removed and a replacement gate is formed on the substrate.
    Type: Application
    Filed: October 3, 2011
    Publication date: April 4, 2013
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Kangguo Cheng, Bruce B. Doris, Balasubramanian S. Haran, Ali Khakifirooz, Pranita Kulkarni
  • Publication number: 20130082311
    Abstract: Transistor devices and methods of their fabrication are disclosed. In one method, a dummy gate structure is formed on a substrate. Bottom portions of the dummy gate structure are undercut. In addition, stair-shaped, raised source and drain regions are formed on the substrate and within at least one undercut formed by the undercutting. The dummy gate structure is removed and a replacement gate is formed on the substrate.
    Type: Application
    Filed: September 11, 2012
    Publication date: April 4, 2013
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Kangguo Cheng, Bruce B. Doris, Balasubramanian S. Haran, Ali Khakifirooz, Pranita Kulkarni
  • Patent number: 8399957
    Abstract: Doped semiconductor back gate regions self-aligned to active regions are formed by first patterning a top semiconductor layer and a buried insulator layer to form stacks of a buried insulator portion and a semiconductor portion. Oxygen is implanted into an underlying semiconductor layer at an angle so that oxygen-implanted regions are formed in areas that are not shaded by the stack or masking structures thereupon. The oxygen implanted portions are converted into deep trench isolation structures that are self-aligned to sidewalls of the active regions, which are the semiconductor portions in the stacks. Dopant ions are implanted into the portions of the underlying semiconductor layer between the deep trench isolation structures to form doped semiconductor back gate regions. A shallow trench isolation structure is formed on the deep trench isolation structures and between the stacks.
    Type: Grant
    Filed: April 8, 2011
    Date of Patent: March 19, 2013
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Balasubramanian S. Haran, Ali Khakifirooz, Ghavam G. Shahidi
  • Patent number: 8394710
    Abstract: A method of forming a semiconductor device is provided, in which the dopant for the source and drain regions is introduced from a doped dielectric layer. In one example, a gate structure is formed on a semiconductor layer of an SOI substrate, in which the thickness of the semiconductor layer is less than 10 nm. A doped dielectric layer is formed over at least the portion of the semiconductor layer that is adjacent to the gate structure. The dopant from the doped dielectric layer is driven into the portion of the semiconductor layer that is adjacent to the gate structure. The dopant diffused into the semiconductor provides source and drain extension regions.
    Type: Grant
    Filed: June 21, 2010
    Date of Patent: March 12, 2013
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Bruce B. Doris, Balasubramanian S. Haran, Ali Khakifirooz, Ghavam G. Shahidi
  • Publication number: 20130049115
    Abstract: At least one drain-side surfaces of a field effect transistor (FET) structure, which can be a structure for a planar FET or a fin FET, is structurally damaged by an angled ion implantation of inert or electrically active dopants, while at least one source-side surface of the transistor is protected from implantation by a gate stack and a gate spacer. Epitaxial growth of a semiconductor material is retarded on the at least one structurally damaged drain-side surface, while epitaxial growth proceeds without retardation on the at least one source-side surface. A raised epitaxial source region has a greater thickness than a raised epitaxial drain region, thereby providing an asymmetric FET having lesser source-side external resistance than drain-side external resistance, and having lesser drain-side overlap capacitance than source-side overlap capacitance.
    Type: Application
    Filed: August 24, 2011
    Publication date: February 28, 2013
    Applicant: International Business Machines Corporation
    Inventors: KANGGUO CHENG, Balasubramanian S. Haran, Shom Ponoth, Theodorus E. Standaert, Tenko Yamashita
  • Patent number: 8383490
    Abstract: After formation of a semiconductor device on a semiconductor-on-insulator (SOI) layer, a first dielectric layer is formed over a recessed top surface of a shallow trench isolation structure. A second dielectric layer that can be etched selective to the first dielectric layer is deposited over the first dielectric layer. A contact via hole for a device component located in or on a top semiconductor layer is formed by an etch. During the etch, the second dielectric layer is removed selective to the first dielectric layer, thereby limiting overetch into the first dielectric layer. Due to the etch selectivity, a sufficient amount of the first dielectric layer is present between the bottom of the contact via hole and a bottom semiconductor layer, thus providing electrical isolation for the ETSOI device from the bottom semiconductor layer.
    Type: Grant
    Filed: July 27, 2011
    Date of Patent: February 26, 2013
    Assignee: International Business Machines Corporation
    Inventors: Su Chen Fan, Balasubramanian S. Haran, David V. Horak
  • Patent number: 8377795
    Abstract: A multiple etch process for forming a gate in a semiconductor structure in which a cut area is first formed followed by the forming of the gate conductor lines.
    Type: Grant
    Filed: February 2, 2010
    Date of Patent: February 19, 2013
    Assignee: International Business Machines Corporation
    Inventors: Sivananda K. Kanakasabapathy, Veeraraghavan S. Basker, Balasubramanian S. Haran
  • Patent number: 8372705
    Abstract: CMOS transistors are formed incorporating a gate electrode having tensely stressed spacers on the gate sidewalls of an n channel field effect transistor and having compressively stressed spacers on the gate sidewalls of a p channel field effect transistor to provide differentially stressed channels in respective transistors to increase carrier mobility in the respective channels.
    Type: Grant
    Filed: January 25, 2011
    Date of Patent: February 12, 2013
    Assignee: International Business Machines Corporation
    Inventors: Lahir Shaik Adam, Sanjay C Mehta, Balasubramanian S Haran, Bruce B. Doris
  • Publication number: 20130032876
    Abstract: A transistor structure includes a channel disposed between a source and a drain; a gate conductor disposed over the channel and between the source and the drain; and a gate dielectric layer disposed between the gate conductor and the source, the drain and the channel. In the transistor structure a lower portion of the source and a lower portion of the drain that are adjacent to the channel are disposed beneath and in contact with the gate dielectric layer to define a sharply defined source-drain extension region. Also disclosed is a replacement gate method to fabricate the transistor structure.
    Type: Application
    Filed: August 1, 2011
    Publication date: February 7, 2013
    Applicant: International Business Machines Corporation
    Inventors: Kangguo CHENG, Bruce B. Doris, Balasubramanian S. Haran, Ali Khakifirooz
  • Publication number: 20130034938
    Abstract: A method includes providing a silicon-on-insulator wafer (e.g., an ETSOI wafer); forming a sacrificial gate structure that overlies a sacrificial insulator layer; forming raised source/drains adjacent to the sacrificial gate structure; depositing a layer that covers the raised source/drains and that surrounds the sacrificial gate structure; and removing the sacrificial gate structure leaving an opening that extends to the sacrificial insulator layer. The method further includes widening the opening so as to expose some of the raised source/drains, removing the sacrificial insulator layer and forming a spacer layer on sidewalls of the opening, the spacer layer covering only an upper portion of the exposed raised source/drains, and depositing a layer of gate dielectric material within the opening. A gate conductor is deposited within the opening.
    Type: Application
    Filed: September 12, 2012
    Publication date: February 7, 2013
    Applicant: International Business Machines Corporation
    Inventors: Kangguo Cheng, Bruce B. Doris, Balasubramanian S. Haran, Ali Khakifirooz
  • Publication number: 20130026570
    Abstract: After formation of a semiconductor device on a semiconductor-on-insulator (SOI) layer, a first dielectric layer is formed over a recessed top surface of a shallow trench isolation structure. A second dielectric layer that can be etched selective to the first dielectric layer is deposited over the first dielectric layer. A contact via hole for a device component located in or on a top semiconductor layer is formed by an etch. During the etch, the second dielectric layer is removed selective to the first dielectric layer, thereby limiting overetch into the first dielectric layer. Due to the etch selectivity, a sufficient amount of the first dielectric layer is present between the bottom of the contact via hole and a bottom semiconductor layer, thus providing electrical isolation for the ETSOI device from the bottom semiconductor layer.
    Type: Application
    Filed: July 27, 2011
    Publication date: January 31, 2013
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Su Chen Fan, Balasubramanian S. Haran, David V. Horak
  • Patent number: 8358012
    Abstract: Contact via holes are etched in a dielectric material layer overlying a semiconductor layer to expose the topmost surface of the semiconductor layer. The contact via holes are extended into the semiconductor material layer by continuing to etch the semiconductor layer so that a trench having semiconductor sidewalls is formed in the semiconductor material layer. A metal layer is deposited over the dielectric material layer and the sidewalls and bottom surface of the trench. Upon an anneal at an elevated temperature, a metal semiconductor alloy region is formed, which includes a top metal semiconductor alloy portion that includes a cavity therein and a bottom metal semiconductor alloy portion that underlies the cavity and including a horizontal portion. A metal contact via is formed within the cavity so that the top metal semiconductor alloy portion laterally surrounds a bottom portion of a bottom portion of the metal contact via.
    Type: Grant
    Filed: August 3, 2010
    Date of Patent: January 22, 2013
    Assignee: International Business Machines Corporation
    Inventors: Balasubramanian S. Haran, Sivananda K. Kanakasabapathy
  • Publication number: 20130015525
    Abstract: An apparatus and a method for creating a CMOS with a dual raised source and drain for NMOS and PMOS. The spacers on both stack gates are of equal thickness. In this method, a first insulating layer is formed on the surface. The first region is then masked while the other region has the first layer etched away and has an epitaxial source and drain grown on the region. A second layer is formed to all exposed surfaces. The second region is then masked while the first region is etched away. The epitaxial source and drain is formed on the first region. The second region can also be masked by adding a thin layer of undoped silicon and then oxidize it. Another way to mask the second region is to use a hard mask. Another way to form the second source and drain is to use amorphous material.
    Type: Application
    Filed: July 11, 2011
    Publication date: January 17, 2013
    Applicant: International Business Machines Corporation
    Inventors: Kangguo Cheng, Bruce B. Doris, Ali Khakifirooz, Balasubramanian S. Haran
  • Publication number: 20130017680
    Abstract: A method of making a gate of a field effect transistor (FET) with improved fill by a replacement gate process using a sacrificial film includes providing a substrate with a dummy gate. It further includes depositing a sacrificial layer and an encapsulating layer over the substrate, and planarizing so that the encapsulating layer, sacrificial layer and dummy gate are co-planar. The encapsulating layer and a portion of the sacrificial film are removed to leave a remaining sacrificial film. The dummy gate is removed to form and opening in the remaining sacrificial film and to expose sidewalls of the film. Spacers are formed on the sidewalls. A high dielectric constant film and metal film are deposited in the opening and planarized to form a gate. The remaining sacrificial film is removed. The method can be used on planar FETs as well non-planar FETs.
    Type: Application
    Filed: July 14, 2011
    Publication date: January 17, 2013
    Applicant: International Business Machines Corporation
    Inventors: Balasubramanian S. Haran, James J. Demarest
  • Publication number: 20130015509
    Abstract: A gate dielectric is patterned after formation of a first gate spacer by anisotropic etch of a conformal dielectric layer to minimize overetching into a semiconductor layer. In one embodiment, selective epitaxy is performed to sequentially form raised epitaxial semiconductor portions, a disposable gate spacer, and raised source and drain regions. The disposable gate spacer is removed and ion implantation is performed into exposed portions of the raised epitaxial semiconductor portions to form source and drain extension regions. In another embodiment, ion implantation for source and drain extension formation is performed through the conformal dielectric layer prior to an anisotropic etch that forms the first gate spacer. The presence of the raised epitaxial semiconductor portions or the conformation dielectric layer prevents complete amorphization of the semiconductor material in the source and drain extension regions, thereby enabling regrowth of crystalline source and drain extension regions.
    Type: Application
    Filed: July 15, 2011
    Publication date: January 17, 2013
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Balasubramanian S. Haran, Hemanth Jagannathan, Sivananda K. Kanakasabapathy, Sanjay Mehta
  • Publication number: 20130015512
    Abstract: A gate dielectric is patterned after formation of a first gate spacer by anisotropic etch of a conformal dielectric layer to minimize overetching into a semiconductor layer. In one embodiment, selective epitaxy is performed to sequentially form raised epitaxial semiconductor portions, a disposable gate spacer, and raised source and drain regions. The disposable gate spacer is removed and ion implantation is performed into exposed portions of the raised epitaxial semiconductor portions to form source and drain extension regions. In another embodiment, ion implantation for source and drain extension formation is performed through the conformal dielectric layer prior to an anisotropic etch that forms the first gate spacer. The presence of the raised epitaxial semiconductor portions or the conformation dielectric layer prevents complete amorphization of the semiconductor material in the source and drain extension regions, thereby enabling regrowth of crystalline source and drain extension regions.
    Type: Application
    Filed: September 6, 2012
    Publication date: January 17, 2013
    Applicant: International Business Machines Corporation
    Inventors: Balasubramanian S. Haran, Hemanth Jagannathan, Sivananda K. Kanakasabapathy, Sanjay Mehta
  • Publication number: 20130001706
    Abstract: In one embodiment a method is provided that includes providing a structure including a semiconductor substrate having at least one device region located therein, and a doped semiconductor layer located on an upper surface of the semiconductor substrate in the at least one device region. After providing the structure, a sacrificial gate region having a spacer located on sidewalls thereof is formed on an upper surface of the doped semiconductor layer. A planarizing dielectric material is then formed and the sacrificial gate region is removed to form an opening that exposes a portion of the doped semiconductor layer. The opening is extended to an upper surface of the semiconductor substrate and then an anneal is performed that causes outdiffusion of dopant from remaining portions of the doped semiconductor layer forming a source region and a drain region in portions of the semiconductor substrate that are located beneath the remaining portions of the doped semiconductor layer.
    Type: Application
    Filed: June 28, 2011
    Publication date: January 3, 2013
    Applicant: International Business Machines Corporation
    Inventors: Balasubramanian S. Haran, Kangguo Cheng, Shom Ponoth, Theodorus E. Standaert, Tenko Yamashita
  • Publication number: 20120326241
    Abstract: Contact via holes are etched in a dielectric material layer overlying a semiconductor layer to expose the topmost surface of the semiconductor layer. The contact via holes are extended into the semiconductor material layer by continuing to etch the semiconductor layer so that a trench having semiconductor sidewalls is formed in the semiconductor material layer. A metal layer is deposited over the dielectric material layer and the sidewalls and bottom surface of the trench. Upon an anneal at an elevated temperature, a metal semiconductor alloy region is formed, which includes a top metal semiconductor alloy portion that includes a cavity therein and a bottom metal semiconductor alloy portion that underlies the cavity and including a horizontal portion. A metal contact via is formed within the cavity so that the top metal semiconductor alloy portion laterally surrounds a bottom portion of a bottom portion of the metal contact via.
    Type: Application
    Filed: September 5, 2012
    Publication date: December 27, 2012
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Balasubramanian S. Haran, Sivananda K. Kanakasabapathy