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: 8679941
    Abstract: A method of forming a semiconductor device is provided where in one embodiment an STI fill is recessed below the pad nitride and pad oxide layers, to a level substantially coplanar with the top surface of the substrate. A thin (having a thickness in the range of about 10 ?-100 ?) wet etch resistant layer is formed in contact with and completely covering at least the top surface of the recessed STI fill material. The thin wet etch resistant layer is more resistant to a wet etch process than at least the pad oxide layer. The thin wet etch resistant layer may be a refractory dielectric material, or a dielectric such as HfOx, AlyOx, ZrOx, HfZrOx, and HfSiOx. The inventive wet etch resistant layer improves the wet etch budget of subsequent wet etch processing steps.
    Type: Grant
    Filed: March 16, 2012
    Date of Patent: March 25, 2014
    Assignee: International Business Machines Corporation
    Inventors: Jason E Cummings, Lisa F Edge, Balasubramanian S. Haran, David V Horak, Hemanth Jagannathan, Sanjay Mehta
  • Publication number: 20140077296
    Abstract: A structure and method for fabricating finFETs of varying effective device widths is disclosed. Groups of fins are shortened by a predetermined amount to achieve an effective device width that is equivalent to a real (non-integer) number of full-sized fins. The bottom of each group of fins is coplanar, while the tops of the fins from the different groups of fins may be at different levels.
    Type: Application
    Filed: September 20, 2012
    Publication date: March 20, 2014
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Tenko Yamashita, Kangguo Cheng, Balasubramanian S. Haran, Shom Ponoth, Theodorus Eduardus Standaert
  • Patent number: 8673708
    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: Grant
    Filed: September 12, 2012
    Date of Patent: March 18, 2014
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Bruce B. Doris, Balasubramanian S. Haran, Ali Khakifirooz
  • Patent number: 8673738
    Abstract: Shallow trench isolation structures are provided for use with UTBB (ultra-thin body and buried oxide) semiconductor substrates, which prevent defect mechanisms from occurring, such as the formation of electrical shorts between exposed portions of silicon layers on the sidewalls of shallow trench of a UTBB substrate, in instances when trench fill material of the shallow trench is subsequently etched away and recessed below an upper surface of the UTBB substrate.
    Type: Grant
    Filed: June 25, 2012
    Date of Patent: March 18, 2014
    Assignee: International Business Machines Corporation
    Inventors: Bruce B. Doris, Kangguo Cheng, Balasubramanian S. Haran, Ali Khakifirooz, Pranita Kulkarni, Arvind Kumar, Shom Ponoth
  • Publication number: 20140070357
    Abstract: A semiconductor substrate having an isolation region and method of forming the same. The method includes the steps of providing a substrate having a substrate layer, a buried oxide (BOX), a silicon on insulator (SOI) layer, a pad oxide layer, and a pad nitride layer, forming a shallow trench region, etching the pad oxide layer to form ears and etching the BOX layer to form undercuts, depositing a liner on the shallow trench region, depositing a soft mask over the surface of the shallow trench region, filling the shallow trench region, etching the soft mask so that it is recessed to the top of the BOX layer, etching the liner off certain regions, removing the soft mask, and filling and polishing the shallow trench region. The liner prevents shorting of the semiconductor device when the contacts are misaligned.
    Type: Application
    Filed: September 12, 2012
    Publication date: March 13, 2014
    Applicant: International Business Machines Corporation
    Inventors: Kangguo Cheng, Balasubramanian S. Haran, Shom Ponoth
  • Publication number: 20140061799
    Abstract: A method is provided for fabricating an integrated circuit that includes multiple transistors. 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: November 6, 2013
    Publication date: March 6, 2014
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Susan S. FAN, Balasubramanian S. HARAN, David V. HORAK, Charles W. KOBURGER
  • Publication number: 20140061582
    Abstract: A mandrel having vertical planar surfaces is formed on a single crystalline semiconductor layer. An epitaxial semiconductor layer is formed on the single crystalline semiconductor layer by selective epitaxy. A first spacer is formed around an upper portion of the mandrel. The epitaxial semiconductor layer is vertically recessed employing the first spacers as an etch mask. A second spacer is formed on sidewalls of the first spacer and vertical portions of the epitaxial semiconductor layer. Horizontal bottom portions of the epitaxial semiconductor layer are etched from underneath the vertical portions of the epitaxial semiconductor layer to form a suspended ring-shaped semiconductor fin that is attached to the mandrel. A center portion of the mandrel is etched employing a patterned mask layer that covers two end portions of the mandrel. A suspended semiconductor fin is provided, which is suspended by a pair of support structures.
    Type: Application
    Filed: August 31, 2012
    Publication date: March 6, 2014
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Kangguo Cheng, James J. Demarest, Balasubramanian S. Haran
  • Publication number: 20140061800
    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: November 13, 2013
    Publication date: March 6, 2014
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Balasubramanian S. Haran, David V. Horak, Charles W. Koburger, III, Shom Ponoth
  • Publication number: 20140061794
    Abstract: A finFET with self-aligned punchthrough stopper and methods of manufacture are disclosed. The method includes forming spacers on sidewalls of a gate structure and fin structures of a finFET device. The method further includes forming a punchthrough stopper on exposed sidewalls of the fin structures, below the spacers. The method further includes diffusing dopants from the punchthrough stopper into the fin structures. The method further includes forming source and drain regions adjacent to the gate structure and fin structures.
    Type: Application
    Filed: August 29, 2012
    Publication date: March 6, 2014
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Kangguo Cheng, Balasubramanian S. Haran, Shom Ponoth, Theodorus E. Standaert, Tenko Yamashita
  • Patent number: 8664050
    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: Grant
    Filed: March 20, 2012
    Date of Patent: March 4, 2014
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Bruce B. Doris, Balasubramanian S. Haran, Ali Khakifirooz, Pranita Kulkarni
  • Publication number: 20140054717
    Abstract: A substrate is provided, having formed thereon a first region and a second region of a complementary type to the first region. A gate dielectric is deposited over the substrate, and a first full metal gate stack is deposited over the gate dielectric. The first full metal gate stack is removed over the first region to produce a resulting structure. Over the resulting structure, a second full metal gate stack is deposited, in contact with the gate dielectric over the first region. The first and second full metal gate stacks are encapsulated.
    Type: Application
    Filed: August 24, 2012
    Publication date: February 27, 2014
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Lisa F. Edge, Hemanth Jagannathan, Balasubramanian S. Haran
  • Publication number: 20140051216
    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 an oxide 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: October 30, 2013
    Publication date: February 20, 2014
    Applicant: International Business Machines Corporation
    Inventors: Kangguo Cheng, Bruce B. Doris, Balasubramanian S. Haran, Ali Khakifirooz
  • Publication number: 20140048857
    Abstract: A process fabricates a fin field-effect-transistor by implanting a dopant into an exposed portion of a semiconductor substrate within a cavity. The cavity is formed in a dielectric layer on the semiconductor substrate. The cavity exposes the 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. A height of the cavity defines a height of the epitaxially grown semiconductor.
    Type: Application
    Filed: October 15, 2013
    Publication date: February 20, 2014
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Kangguo CHENG, Balasubramanian S. HARAN, Shom PONOTH, Theodorus E. STANDAERT, Tenko YAMASHITA
  • Publication number: 20140045312
    Abstract: A process fabricates a fin field-effect-transistor 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 15, 2013
    Publication date: February 13, 2014
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Kangguo CHENG, Balasubramanian S. HARAN, Shom PONOTH, Theodorus E. STANDAERT, Tenko YAMASHITA
  • Patent number: 8642415
    Abstract: A method of creating a semiconductor integrated circuit is disclosed. The method includes forming a first field effect transistor (FET) device and a second FET device on a semiconductor substrate. The method includes epitaxially growing raised source/drain (RSD) structures for the first FET device at a first height. The method includes epitaxially growing raised source/drain (RSD) structures for the second FET device at a second height. The second height is greater than the first height such that a threshold voltage of the second FET device is greater than a threshold voltage of the first FET device.
    Type: Grant
    Filed: June 4, 2012
    Date of Patent: February 4, 2014
    Assignee: International Business Machines Corporation
    Inventors: Thomas N. Adam, Kangguo Cheng, Bruce B. Doris, Balasubramanian S. Haran, Pranita Kulkarni, Alexander Reznicek
  • Publication number: 20140024198
    Abstract: A method for fin field effect transistor (finFET) device formation includes forming a plurality of fins on a substrate; forming a gate region over the plurality of fins; and forming isolation areas for the finFET device after formation of the gate region, wherein forming the isolation areas for the finFET device comprises performing one of oxidation or removal of a subset of the plurality of fins.
    Type: Application
    Filed: July 18, 2012
    Publication date: January 23, 2014
    Applicant: International Business Machines Corporation
    Inventors: Balasubramanian S. Haran, Sanjay Mehta, Theodorus E. Standaert
  • Patent number: 8633085
    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: January 14, 2013
    Date of Patent: January 21, 2014
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Balasubramanian S. Haran, Ali Khakifirooz, Ghavam G. Shahidi
  • Publication number: 20140017859
    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 17, 2013
    Publication date: January 16, 2014
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Kangguo CHENG, Ali KHAKIFIROOZ, Sivananda KANAKASABAPATHY, Pranita KULKARNI, Balasubramanian S. HARAN
  • Patent number: 8629008
    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: Grant
    Filed: January 11, 2012
    Date of Patent: January 14, 2014
    Assignee: International Business Machines Corporation
    Inventors: Balasubramanian S. Haran, David V. Horak, Charles W. Koburger, III, Shom Ponoth
  • Patent number: 8629007
    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: Grant
    Filed: July 14, 2011
    Date of Patent: January 14, 2014
    Assignee: International Business Machines Corporation
    Inventors: Balasubramanian S. Haran, James J. Demarest