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).

  • Patent number: 8569125
    Abstract: A FinFET with improved gate planarity and method of fabrication is disclosed. The gate is disposed on a pattern of fins prior to removing any unwanted fins. Lithographic techniques or etching techniques or a combination of both may be used to remove the unwanted fins. All or some of the remaining fins may be merged.
    Type: Grant
    Filed: November 30, 2011
    Date of Patent: October 29, 2013
    Assignee: International Business Machines Corporation
    Inventors: Theodorus Eduardus Standaert, Kangguo Cheng, Balasubramanian S. Haran, Shom Ponoth, Soon-Cheon Seo, Tenko Yamashita
  • Patent number: 8569152
    Abstract: A method for making dual-epi FinFETs is described. The method includes adding a first epitaxial material to an array of fins. The method also includes covering at least a first portion of the array of fins using a first masking material and removing the first epitaxial material from an uncovered portion of the array of fins. Adding a second epitaxial material to the fins in the uncovered portion of the array of fins is included in the method. The method also includes covering a second portion of the array of fins using a second masking material and performing a directional etch using the first masking material and the second masking material. Apparatus and computer program products are also described.
    Type: Grant
    Filed: June 4, 2012
    Date of Patent: October 29, 2013
    Assignee: International Business Machines Corporation
    Inventors: Veeraraghavan S. Basker, Huiming Bu, Kangguo Cheng, Balasubramanian S. Haran, Nicolas Loubet, Shom Ponoth, Stefan Schmitz, Theodorus E Standaert, Tenko Yamashita
  • Publication number: 20130264641
    Abstract: A thin BOX ETSOI device with robust isolation and method of manufacturing. The method includes providing a wafer with at least a pad layer overlying a first semiconductor layer overlying an oxide layer overlying a second semiconductor layer, wherein the first semiconductor layer has a thickness of 10 nm or less. The process continues with etching a shallow trench into the wafer, extending partially into the second semiconductor layer and forming first spacers on the sidewalls of said shallow trench. After spacer formation, the process continues by etching an area directly below and between the first spacers, exposing the underside of the first spacers, forming second spacers covering all exposed portions of the first spacers, wherein the pad oxide layer is removed, and forming a gate structure over the first semiconductor wafer.
    Type: Application
    Filed: April 9, 2012
    Publication date: October 10, 2013
    Applicant: International Business Machines Corporation
    Inventors: Kangguo Cheng, Bruce B. Doris, Balasubramanian S. Haran, Sanjay Mehta, Stefan Schmitz
  • Patent number: 8551872
    Abstract: A transistor structure includes a channel located in an extremely thin silicon on insulator (ETSOI) layer and disposed between a raised source and a raised drain, a gate structure having a gate conductor disposed over the channel and between the source and the drain, and a gate spacer layer disposed over the gate conductor. The raised source and the raised drain each have a facet that is upwardly sloping away from the gate structure. A lower portion of the source and a lower portion of the drain are separated from the channel by an extension region containing a dopant species diffused from a dopant-containing glass.
    Type: Grant
    Filed: September 19, 2012
    Date of Patent: October 8, 2013
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Chen, Bruce B. Doris, Balasubramanian S. Haran, Amlan Majumdar, Sanjay Mehta
  • Publication number: 20130249002
    Abstract: A structure and method to improve ETSOI MOSFET devices. A wafer is provided including regions with at least a first semiconductor layer overlying an oxide layer overlying a second semiconductor layer. The regions are separated by a STI which extends at least partially into the second semiconductor layer and is partially filled with a dielectric. A gate structure is formed over the first semiconductor layer and during the wet cleans involved, the STI divot erodes until it is at a level below the oxide layer. Another dielectric layer is deposited over the device and a hole is etched to reach source and drain regions. The hole is not fully landed, extending at least partially into the STI, and an insulating material is deposited in said hole.
    Type: Application
    Filed: March 20, 2012
    Publication date: September 26, 2013
    Applicant: International Business Machines Corporation
    Inventors: Kangguo Cheng, Bruce B. Doris, Balasubramanian S. Haran, Ali Khakifirooz, Pranita Kulkarni
  • Publication number: 20130200467
    Abstract: A structure and method for forming a dual metal fill and dual threshold voltage for replacement gate metal devices is disclosed. A selective deposition process involving titanium and aluminum is used to allow formation of two adjacent transistors with different fill metals and different workfunction metals, enabling different threshold voltages in the adjacent transistors.
    Type: Application
    Filed: February 7, 2012
    Publication date: August 8, 2013
    Applicant: International Business Machines Corporation
    Inventors: Lisa F. Edge, Nathaniel Berliner, James John Demarest, Balasubramanian S. Haran
  • Patent number: 8486778
    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: Grant
    Filed: July 15, 2011
    Date of Patent: July 16, 2013
    Assignee: International Business Machines Corporation
    Inventors: Balasubramanian S. Haran, Hemanth Jagannathan, Sivananda K. Kanakasabapathy, Sanjay Mehta
  • Publication number: 20130175625
    Abstract: A transistor structure includes a channel located in an extremely thin silicon on insulator (ETSOI) layer and disposed between a raised source and a raised drain, a gate structure having a gate conductor disposed over the channel and between the source and the drain, and a gate spacer layer disposed over the gate conductor. The raised source and the raised drain each have a facet that is upwardly sloping away from the gate structure. A lower portion of the source and a lower portion of the drain are separated from the channel by an extension region containing a dopant species diffused from a dopant-containing glass.
    Type: Application
    Filed: September 19, 2012
    Publication date: July 11, 2013
    Applicant: International Business Machines Corporation
    Inventors: Kangguo Cheng, Bruce B. Doris, Balasubramanian S. Haran, Amlan Majumdar, Sanjay Mehta
  • Publication number: 20130175622
    Abstract: After formation of raised source and drain regions, a conformal dielectric material liner is deposited within recessed regions formed by removal of shallow trench isolation structures and underlying portions of a buried insulator layer in a semiconductor-on-insulator (SOI) substrate. A dielectric material that is different from the material of the conformal dielectric material liner is subsequently deposited and planarized to form a planarized dielectric material layer. The planarized dielectric material layer is recessed selective to the conformal dielectric material liner to form dielectric fill portions that fill the recessed regions. Horizontal portions of the conformal dielectric material liner are removed by an anisotropic etch, while remaining portions of the conformal dielectric material liner form an outer gate spacer. At least one contact-level dielectric layer is deposited. Contact via structures electrically isolated from a handle substrate can be formed within the contact via holes.
    Type: Application
    Filed: January 11, 2012
    Publication date: July 11, 2013
    Applicant: International Business Machines Corporation
    Inventors: Balasubramanian S. Haran, David V. Horak, Charles W. Koburger, III, Shom Ponoth
  • Publication number: 20130175619
    Abstract: A transistor includes a semiconductor layer, a gate spacer on the semiconductor layer, a gate dielectric comprising a first portion above the semiconductor layer and a second portion on sidewalls of the gate spacer, a work function metal layer comprising a first portion on the first portion of the gate dielectric and a second portion on sidewalls of the gate dielectric, a gate conductor on the first portion of the work function layer and abutting the second portion of the work function layer, a dielectric layer on the semiconductor layer and abutting the gate spacer, an oxide film above only one of the work function layer and the gate conductor, an oxide cap, source/drain regions, and a source/drain contact passing through the dielectric layer and contacting an upper surface of one of the source/drain regions. A portion of the source/drain contact is located directly on the oxide cap.
    Type: Application
    Filed: January 6, 2012
    Publication date: July 11, 2013
    Applicant: International Business Machines Corporation
    Inventors: Susan S. FAN, Balasubramanian S. HARAN, David V. HORAK, Charles W. KOBURGER, III
  • Publication number: 20130175618
    Abstract: A method for fabricating a field effect transistor device includes removing a portion of a first semiconductor layer and a first insulator layer to expose a portion of a second semiconductor layer, wherein the second semiconductor layer is disposed on a second insulator layer, the first insulator layer is disposed on the second semiconductor layer, and the first semiconductor layer is disposed on the first insulator layer, removing portions of the first semiconductor layer to form a first fin disposed on the first insulator layer and removing portions of the second semiconductor layer to form a second fin disposed on the second insulator layer, and forming a first gate stack over a portion of the first fin and forming a second gate stack over a portion of the second fin.
    Type: Application
    Filed: January 5, 2012
    Publication date: July 11, 2013
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Kangguo Cheng, Balasubramanian S. Haran, Shom Ponoth, Theodorus E. Standaert, Tenko Yamashita
  • Publication number: 20130178022
    Abstract: A method is provided for fabricating a transistor. According to the method, a second semiconductor layer is formed on a first semiconductor layer, and a dummy gate structure is formed on the second semiconductor layer. A gate spacer is formed on sidewalls of the dummy gate structure, and the dummy gate structure is removed to form a cavity. The second semiconductor layer beneath the cavity is removed. A gate dielectric is formed on the first portion of the first semiconductor layer and adjacent to the sidewalls of the second semiconductor layer and sidewalls of the gate spacer. A gate conductor is formed on the first portion of the gate dielectric and abutting the second portion of the gate dielectric. Raised source/drain regions are formed in the second semiconductor layer, with at least part of the raised source/drain regions being below the gate spacer.
    Type: Application
    Filed: September 14, 2012
    Publication date: July 11, 2013
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Kangguo CHENG, Ali KHAKIFIROOZ, Sivananda KANAKASABAPATHY, Pranita KULKARNI, Balasubramanian S. HARAN
  • Publication number: 20130178052
    Abstract: A method is provided for fabricating a transistor. A replacement gate stack is formed on a semiconductor layer, a gate spacer is formed, and a dielectric layer is formed. The dummy gate stack is removed to form a cavity. A gate dielectric and a work function metal layer are formed in the cavity. The cavity is filled with a gate conductor. One and only one of the gate conductor and the work function metal layer are selectively recessed. An oxide film is formed in the recess such that its upper surface is co-planar with the upper surface of the dielectric layer. The oxide film is used to selectively grow an oxide cap. An interlayer dielectric is formed and etched to form a cavity for a source/drain contact. A source/drain contact is formed in the contact cavity, with a portion of the source/drain contact being located directly on the oxide cap.
    Type: Application
    Filed: September 14, 2012
    Publication date: July 11, 2013
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Susan S. FAN, Balasubramanian S. HARAN, David V. HORAK, Charles W. KOBURGER, II
  • Publication number: 20130175579
    Abstract: A transistor includes a first semiconductor layer. A second semiconductor layer is located on the first semiconductor layer. A portion of the second semiconductor layer is removed to expose a first portion of the first semiconductor layer and to provide vertical sidewalls of the second semiconductor layer. A gate spacer is located on the second semiconductor layer. A gate dielectric includes a first portion located on the first portion of the first semiconductor layer and a second portion adjacent to the vertical sidewalls of the second semiconductor layer. A gate conductor is located on the first portion of the gate dielectric and abuts the gate dielectric second portion. A channel region is located in at least part of the first portion of the first semiconductor layer. Raised source/drain regions are located in the second semiconductor layer. At least part of the raised source/drain regions is located below the gate spacer.
    Type: Application
    Filed: January 10, 2012
    Publication date: July 11, 2013
    Applicant: International Business Machines Corporation
    Inventors: Kangguo Cheng, Ali Khakifirooz, Sivananda Kanakasabapathy, Pranita Kulkarni, Balasubramanian S. Haran
  • Patent number: 8455932
    Abstract: A common cut mask is employed to define a gate pattern and a local interconnect pattern so that local interconnect structures and gate structures are formed with zero overlay variation relative to one another. A local interconnect structure may be laterally spaced from a gate structure in a first horizontal direction, and contact another gate structure in a second horizontal direction that is different from the first horizontal direction. Further, a gate structure may be formed to be collinear with a local interconnect structure that adjoins the gate structure. The local interconnect structures and the gate structures are formed by a common damascene processing step so that the top surfaces of the gate structures and the local interconnect structures are coplanar with each other.
    Type: Grant
    Filed: May 6, 2011
    Date of Patent: June 4, 2013
    Assignee: International Business Machines Corporation
    Inventors: Ali Khakifirooz, Kangguo Cheng, Bruce B. Doris, Wilfried E. Haensch, Balasubramanian S. Haran, Pranita Kulkarni
  • Publication number: 20130134513
    Abstract: A FinFET with improved gate planarity and method of fabrication is disclosed. The gate is disposed on a pattern of fins prior to removing any unwanted fins. Lithographic techniques or etching techniques or a combination of both may be used to remove the unwanted fins. All or some of the remaining fins may be merged.
    Type: Application
    Filed: November 30, 2011
    Publication date: May 30, 2013
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Theodorus Eduardus Standaert, Kangguo Cheng, Balasubramanian S. Haran, Shom Ponoth, Soon-Cheon Seo, Tenko Yamashita
  • Patent number: 8440552
    Abstract: A method includes providing an ETSOI wafer having a semiconductor layer having a top surface with at least one gate structure having on sidewalls thereof a layer of dielectric material. A portion of the layer of dielectric material extends away from the gate structure on the surface of the semiconductor layer. The method further includes faulting a raised S/D on the semiconductor layer adjacent to the portion of the layer of dielectric material, removing the portion of the layer of dielectric material to expose an underlying portion of the surface of the semiconductor layer and applying a layer of glass containing a dopant to cover at least the exposed portion of the surface of the semiconductor layer. The method further includes diffusing the dopant through the exposed portion of the surface of the semiconductor layer to form a source extension region and a drain extension region.
    Type: Grant
    Filed: January 9, 2012
    Date of Patent: May 14, 2013
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Chen, Bruce B. Doris, Balasubramanian S. Haran, Amlan Majumdar, Sanjay Mehta
  • Patent number: 8435846
    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: Grant
    Filed: October 3, 2011
    Date of Patent: May 7, 2013
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Bruce B. Doris, Balasubramanian S. Haran, Ali Khakifirooz, Pranita Kulkarni
  • Patent number: 8432002
    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: Grant
    Filed: June 28, 2011
    Date of Patent: April 30, 2013
    Assignee: International Business Machines Corporation
    Inventors: Balasubramanian S. Haran, Kangguo Cheng, Shom Ponoth, Theodorus E. Standaert, Tenko Yamashita
  • Publication number: 20130102119
    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: September 13, 2012
    Publication date: April 25, 2013
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Kangguo CHENG, Balasubramanian S. HARAN, Shom PONOTH, Theodorus E. STANDAERT, Tenko YAMASHITA