Patents by Inventor Shreesh Narasimha

Shreesh Narasimha 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: 9287399
    Abstract: A faceted intrinsic buffer semiconductor material is deposited on sidewalls of a source trench and a drain trench by selective epitaxy. A facet adjoins each edge at which an outer sidewall of a gate spacer adjoins a sidewall of the source trench or the drain trench. A doped semiconductor material is subsequently deposited to fill the source trench and the drain trench. The doped semiconductor material can be deposited such that the facets of the intrinsic buffer semiconductor material are extended and inner sidewalls of the deposited doped semiconductor material merges in each of the source trench and the drain trench. The doped semiconductor material can subsequently grow upward. Faceted intrinsic buffer semiconductor material portions allow greater outdiffusion of dopants near faceted corners while suppressing diffusion of dopants in regions of uniform width, thereby suppressing short channel effects.
    Type: Grant
    Filed: October 7, 2014
    Date of Patent: March 15, 2016
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Bhupesh Chandra, Paul Chang, Gregory G. Freeman, Dechao Guo, Judson R. Holt, Arvind Kumar, Timothy J. McArdle, Shreesh Narasimha, Viorel Ontalus, Sangameshwar Saudari, Christopher D. Sheraw, Matthew W. Stoker
  • Patent number: 9269786
    Abstract: Standard High-K metal gate (HKMG) CMOS technologies fabricated using the replacement metal gate (RMG), also known as gate-last, integration flow, are susceptible to oxygen ingress into the high-K gate dielectric layer and oxygen diffusion into the gate dielectric and semiconductor channel region. The oxygen at the gate dielectric and semiconductor channel interface induces unwanted oxide regrowth that results in an effective oxide thickness increase, and transistor threshold voltage shifts, both of which are highly variable and degrade semiconductor chip performance. By introducing silicon nitride deposited at low temperature, after the metal gate formation, the oxygen ingress and gate dielectric regrowth can be avoided, and a high semiconductor chip performance is maintained.
    Type: Grant
    Filed: September 26, 2013
    Date of Patent: February 23, 2016
    Assignee: GLOBALFOUNDRIES Inc.
    Inventors: Anthony I-Chih Chou, Arvind Kumar, Shreesh Narasimha, Claude Ortolland, Kai Zhao
  • Patent number: 9252146
    Abstract: A device including a p-type semiconductor device and an n-type semiconductor device on a semiconductor substrate. The n-type semiconductor device includes a gate structure having a high-k gate dielectric. A carbon dopant in a concentration ranging from 1×1016 atoms/cm3 to 1×1021 atoms/cm3 is present at an interface between the high-k gate dielectric of the gate structure for the n-type semiconductor device and the semiconductor substrate. Methods of forming the aforementioned device are also disclosed.
    Type: Grant
    Filed: May 19, 2014
    Date of Patent: February 2, 2016
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Yue Liang, Dechao Guo, William K. Henson, Shreesh Narasimha, Yanfeng Wang
  • Patent number: 9240482
    Abstract: A stressor structure is formed within a drain region of an access transistor in a dynamic random access memory (DRAM) cell in a semiconductor-on-insulator (SOI) substrate without forming any stressor structure in a source region of the DRAM cell. The stressor structure induces a stress gradient within the body region of the access transistor, which induces a greater leakage current at the body-drain junction than at the body-source junction. The body potential of the access transistor has a stronger coupling to the drain voltage than to the source voltage. An asymmetric etch of a gate dielectric cap, application of a planarization material layer, and a non-selective etch of the planarization material layer and the gate dielectric cap can be employed to form the DRAM cell.
    Type: Grant
    Filed: September 4, 2014
    Date of Patent: January 19, 2016
    Assignee: GLOBALFOUNDRIES INC.
    Inventors: Ravi K. Dasaka, Shreesh Narasimha, Ahmed Nayaz Noemaun, Karen A. Nummy, Katsunori Onishi, Paul C. Parries, Chengwen Pei, Geng Wang, Bidan Zhang
  • Publication number: 20160013181
    Abstract: A metal-oxide-semiconductor field-effect transistor (MOSFET) with integrated passive structures and methods of manufacturing the same is disclosed. The method includes forming a stacked structure in an active region and at least one shallow trench isolation (STI) structure adjacent to the stacked structure. The method further includes forming a semiconductor layer directly in contact with the at least one STI structure and the stacked structure. The method further includes patterning the semiconductor layer and the stacked structure to form an active device in the active region and a passive structure of the semiconductor layer directly on the at least one STI structure.
    Type: Application
    Filed: September 24, 2015
    Publication date: January 14, 2016
    Inventors: Anthony I. Chou, Arvind Kumar, Renee T. Mo, Shreesh Narasimha
  • Publication number: 20160013093
    Abstract: A metal-oxide-semiconductor field-effect transistor (MOSFET) with integrated passive structures and methods of manufacturing the same is disclosed. The method includes forming a stacked structure in an active region and at least one shallow trench isolation (STI) structure adjacent to the stacked structure. The method further includes forming a semiconductor layer directly in contact with the at least one STI structure and the stacked structure. The method further includes patterning the semiconductor layer and the stacked structure to form an active device in the active region and a passive structure of the semiconductor layer directly on the at least one STI structure.
    Type: Application
    Filed: September 24, 2015
    Publication date: January 14, 2016
    Inventors: Anthony I. Chou, Arvind Kumar, Renee T. Mo, Shreesh Narasimha
  • Patent number: 9219059
    Abstract: A metal-oxide-semiconductor field-effect transistor (MOSFET) with integrated passive structures and methods of manufacturing the same is disclosed. The method includes forming a stacked structure in an active region and at least one shallow trench isolation (STI) structure adjacent to the stacked structure. The method further includes forming a semiconductor layer directly in contact with the at least one STI structure and the stacked structure. The method further includes patterning the semiconductor layer and the stacked structure to form an active device in the active region and a passive structure of the semiconductor layer directly on the at least one STI structure.
    Type: Grant
    Filed: September 26, 2012
    Date of Patent: December 22, 2015
    Assignee: International Business Machines Corporation
    Inventors: Anthony I. Chou, Arvind Kumar, Renee T. Mo, Shreesh Narasimha
  • Publication number: 20150348974
    Abstract: The present invention relates generally to semiconductor devices and more particularly, to a structure and method of forming a junction butting region using low energy ion implantation to reduce parasitic leakage and body-to-body leakage between adjacent FETs that share a common contact in high density memory technologies, such as dynamic random access memory (DRAM) devices and embedded DRAM (eDRAM) devices. A method disclosed may include forming a junction butting region at the bottom of a trench formed in a semiconductor on insulator (SOI) layer using low energy ion implantation and protecting adjacent structures from damage from ion scattering using a protective layer.
    Type: Application
    Filed: August 7, 2015
    Publication date: December 3, 2015
    Inventors: Shreesh Narasimha, Katsunori Onishi, Paul C. Parries, Chengwen Pei, Geng Wang
  • Publication number: 20150348972
    Abstract: A stressor structure is formed within a drain region of an access transistor in a dynamic random access memory (DRAM) cell in a semiconductor-on-insulator (SOI) substrate without forming any stressor structure in a source region of the DRAM cell. The stressor structure induces a stress gradient within the body region of the access transistor, which induces a greater leakage current at the body-drain junction than at the body-source junction. The body potential of the access transistor has a stronger coupling to the drain voltage than to the source voltage. The asymmetric stressor enables low leakage current for the body region during charge storage while the drain voltage is low, and enables a body potential coupled to the drain region and a lower threshold voltage for the access transistor during read and write operations.
    Type: Application
    Filed: May 30, 2014
    Publication date: December 3, 2015
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Shreesh Narasimha, Katsunori Onishi, Paul C. Parries, Chengwen Pei, Geng Wang
  • Publication number: 20150349121
    Abstract: A stressor structure is formed within a drain region of an access transistor in a dynamic random access memory (DRAM) cell in a semiconductor-on-insulator (SOI) substrate without forming any stressor structure in a source region of the DRAM cell. The stressor structure induces a stress gradient within the body region of the access transistor, which induces a greater leakage current at the body-drain junction than at the body-source junction. The body potential of the access transistor has a stronger coupling to the drain voltage than to the source voltage. An asymmetric etch of a gate dielectric cap, application of a planarization material layer, and a non-selective etch of the planarization material layer and the gate dielectric cap can be employed to form the DRAM cell.
    Type: Application
    Filed: September 4, 2014
    Publication date: December 3, 2015
    Inventors: Ravi K. Dasaka, Shreesh Narasimha, Ahmed Nayaz Noemaun, Karen A. Nummy, Katsunori Onishi, Paul C. Parries, Chengwen Pei, Geng Wang, Bidan Zhang
  • Publication number: 20150333145
    Abstract: Embodiments of the present invention provide a finFET and method of fabrication to achieve advantages of both merged and unmerged fins. A first step of epitaxy is performed with either partial diamond or full diamond growth. This is followed by a second step of deposition of a semiconductor cap region on the finFET source/drain area using a directional deposition process, followed by an anneal to perform Solid Phase Epitaxy or poly recrystalization. As a result, the fins remain unmerged, but the epitaxial volume is increased to provide reduced contact resistance. Embodiments of the present invention allow a narrower fin pitch, which enables increased circuit density on an integrated circuit.
    Type: Application
    Filed: May 15, 2014
    Publication date: November 19, 2015
    Applicant: International Business Machines Corporation
    Inventors: Michael P. Chudzik, Brian J. Greene, Edward P. Maciejewski, Kevin McStay, Shreesh Narasimha, Chengwen Pei, Werner A. Rausch
  • Patent number: 9184301
    Abstract: An integrated circuit includes a plurality of gate-all-around (GAA) nanowire field effect transistors (FETs), a plurality of omega-gate nanowire FETs, and a plurality of planar channel FETs, wherein the plurality of GAA FETs, the plurality of omega-gate nanowire FETs, and the plurality of planar channel FETs are disposed on a single wafer.
    Type: Grant
    Filed: August 31, 2012
    Date of Patent: November 10, 2015
    Assignee: GLOBALFOUNDRIES INC.
    Inventors: Sarunya Bangsaruntip, Guy M. Cohen, Shreesh Narasimha, Jeffrey W. Sleight
  • Patent number: 9136321
    Abstract: The present invention relates generally to semiconductor devices and more particularly, to a structure and method of forming a junction butting region using low energy ion implantation to reduce parasitic leakage and body-to-body leakage between adjacent FETs that share a common contact in high density memory technologies, such as dynamic random access memory (DRAM) devices and embedded DRAM (eDRAM) devices. A method disclosed may include forming a junction butting region at the bottom of a trench formed in a semiconductor on insulator (SOI) layer using low energy ion implantation and protecting adjacent structures from damage from ion scattering using a protective layer.
    Type: Grant
    Filed: April 30, 2014
    Date of Patent: September 15, 2015
    Assignee: International Business Machines Corporation
    Inventors: Shreesh Narasimha, Katsunori Onishi, Paul C. Parries, Chengwen Pei, Geng Wang
  • Patent number: 9105718
    Abstract: A structure, a FET, a method of making the structure and of making the FET. The structure including: a silicon layer on a buried oxide (BOX) layer of a silicon-on-insulator substrate; a trench in the silicon layer extending from a top surface of the silicon layer into the silicon layer, the trench not extending to the BOX layer, a doped region in the silicon layer between and abutting the BOX layer and a bottom of the trench, the first doped region doped to a first dopant concentration; a first epitaxial layer, doped to a second dopant concentration, in a bottom of the trench; a second epitaxial layer, doped to a third dopant concentration, on the first epitaxial layer in the trench; and wherein the third dopant concentration is greater than the first and second dopant concentrations and the first dopant concentration is greater than the second dopant concentration.
    Type: Grant
    Filed: March 25, 2014
    Date of Patent: August 11, 2015
    Assignee: International Business Machines Corporation
    Inventors: Jeffrey B. Johnson, Shreesh Narasimha, Hasan M. Nayfeh, Viorel Ontalus, Robert R. Robison
  • Patent number: 9082877
    Abstract: A complementary metal oxide semiconductor (CMOS) device including a substrate including a first active region and a second active region, wherein each of the first active region and second active region of the substrate are separated by from one another by an isolation region. A n-type semiconductor device is present on the first active region of the substrate, in which the n-type semiconductor device includes a first portion of a gate structure. A p-type semiconductor device is present on the second active region of the substrate, in which the p-type semiconductor device includes a second portion of the gate structure. A connecting gate portion provides electrical connectivity between the first portion of the gate structure and the second portion of the gate structure. Electrical contact to the connecting gate portion is over the isolation region, and is not over the first active region and/or the second active region.
    Type: Grant
    Filed: May 30, 2014
    Date of Patent: July 14, 2015
    Assignee: International Business Machines Corporation
    Inventors: Yue Liang, Dureseti Chidambarrao, Brian J. Greene, William K. Henson, Unoh Kwon, Shreesh Narasimha, Xiaojun Yu
  • Patent number: 9064972
    Abstract: A method of fabricating a semiconductor structure provided with a plurality of gated-diodes having a silicided anode (p-doped region) and cathode (n-doped region) and a high-K gate stack made of non-silicided gate material, the gated-diodes being adjacent to FETs, each of which having a silicided source, a silicided drain and a silicided HiK gate stack. The semiconductor structure eliminates a cap removal RIE in a gate first High-K metal gate flow from the region of the gated-diode. The lack of silicide and the presence of a nitride barrier on the gate of the diode are preferably made during the gate first process flow. The absence of the cap removal RIE is beneficial in that diffusions of the diode are not subjected to the cap removal RIE, which avoids damage and allows retaining its highly ideal junction characteristics.
    Type: Grant
    Filed: March 20, 2014
    Date of Patent: June 23, 2015
    Assignee: International Business Machines Corporation
    Inventors: Anthony I. Chou, Arvind Kumar, Edward P. Maciejewski, Shreesh Narasimha, Dustin K. Slisher
  • Patent number: 9040399
    Abstract: A structure includes a substrate; a transistor disposed over the substrate, the transistor comprising a fin comprised of Silicon that is implanted with Carbon; and a gate dielectric layer and gate metal layer overlying a portion of the fin that defines a channel of the transistor. In the structure a concentration of Carbon within the fin is selected to establish a desired voltage threshold of the transistor. Methods to fabricate a FinFET transistor are also disclosed. Also disclosed is a planar transistor having a Carbon-implanted well where the concentration of the Carbon within the well is selected to establish a desired voltage threshold of the transistor.
    Type: Grant
    Filed: October 27, 2011
    Date of Patent: May 26, 2015
    Assignee: International Business Machines Corporation
    Inventors: MaryJane Brodsky, Ming Cai, Dechao Guo, William K. Henson, Shreesh Narasimha, Yue Liang, Liyang Song, Yanfeng Wang, Chun-Chen Yeh
  • Publication number: 20150084132
    Abstract: Standard High-K metal gate (HKMG) CMOS technologies fabricated using the replacement metal gate (RMG), also known as gate-last, integration flow, are susceptible to oxygen ingress into the high-K gate dielectric layer and oxygen diffusion into the gate dielectric and semiconductor channel region. The oxygen at the gate dielectric and semiconductor channel interface induces unwanted oxide regrowth that results in an effective oxide thickness increase, and transistor threshold voltage shifts, both of which are highly variable and degrade semiconductor chip performance. By introducing silicon nitride deposited at low temperature, after the metal gate formation, the oxygen ingress and gate dielectric regrowth can be avoided, and a high semiconductor chip performance is maintained.
    Type: Application
    Filed: September 26, 2013
    Publication date: March 26, 2015
    Applicant: International Business Machines Corporation
    Inventors: Anthony I-Chih Chou, Arvind Kumar, Shreesh Narasimha, Claude Ortolland, Kai Zhao
  • Publication number: 20150084096
    Abstract: A faceted intrinsic buffer semiconductor material is deposited on sidewalls of a source trench and a drain trench by selective epitaxy. A facet adjoins each edge at which an outer sidewall of a gate spacer adjoins a sidewall of the source trench or the drain trench. A doped semiconductor material is subsequently deposited to fill the source trench and the drain trench. The doped semiconductor material can be deposited such that the facets of the intrinsic buffer semiconductor material are extended and inner sidewalls of the deposited doped semiconductor material merges in each of the source trench and the drain trench. The doped semiconductor material can subsequently grow upward. Faceted intrinsic buffer semiconductor material portions allow greater outdiffusion of dopants near faceted corners while suppressing diffusion of dopants in regions of uniform width, thereby suppressing short channel effects.
    Type: Application
    Filed: October 7, 2014
    Publication date: March 26, 2015
    Inventors: Bhupesh Chandra, Paul Chang, Gregory G. Freeman, Dechao Guo, Judson R. Holt, Arvind Kumar, Timothy J. McArdle, Shreesh Narasimha, Viorel Ontalus, Sangameshwar Saudari, Christopher D. Sheraw, Matthew W. Stoker
  • Publication number: 20150054080
    Abstract: A semiconductor structure and method for forming a shallow trench isolation (STI) structure having one or more oxide layers and a nitride plug. Specifically, the structure and method involves forming one or more trenches in a substrate. The STI structure is formed having one or more oxide layers and a nitride plug, wherein the STI structure is formed on and adjacent to at least one of the one or more trenches. One or more gates are formed on the substrate and spaced at a distance from each other. A dielectric layer is formed on and adjacent to the substrate, the STI structure, and the one or more gates.
    Type: Application
    Filed: November 4, 2014
    Publication date: February 26, 2015
    Inventors: Byeong Y. Kim, Shreesh Narasimha