Patents by Inventor Siddarth Krishnan

Siddarth Krishnan 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: 20160190015
    Abstract: A method of fabricating advanced node field effect transistors using a replacement metal gate process. The method includes dopant a high-k dielectric directly or indirectly by using layers composed of multi-layer thin film stacks, or in other embodiments, by a single blocking layer. By taking advantage of unexpected etch selectivity of the multi-layer stack or the controlled etch process of a single layer stack, etch damage to the high-k may be avoided and work function metal thicknesses can be tightly controlled which in turn allows field effect transistors with low Tinv (inverse of gate capacitance) mismatch.
    Type: Application
    Filed: March 2, 2016
    Publication date: June 30, 2016
    Inventors: Takashi Ando, Hemanth Jagannathan, Balaji Kannan, Siddarth A. Krishnan, Unoh Kwon, Rekha Rajaram
  • Patent number: 9373690
    Abstract: A method of forming a semiconductor device includes forming first and second semiconductor structures on a semiconductor substrate. The first semiconductor structure includes a first gate channel region having a first gate length, and the second semiconductor structure including a second gate channel region having a second gate length that is greater than the first gate length. The method further includes depositing a work function metal layer in each of a first gate void formed at the first gate channel region and a second gate void formed at the second gate channel region. The method further includes depositing a semiconductor masking layer on the work function metal layer, and simultaneously etching the silicon masking layer located at the first and second gate channel regions to re-expose the first and second gate voids. A low-resistive metal is deposited in the first and second gate voids to form low-resistive metal gate stacks.
    Type: Grant
    Filed: August 14, 2015
    Date of Patent: June 21, 2016
    Assignee: GLOBALFOUNDRIES INC.
    Inventors: Michael P. Chudzik, Siddarth A. Krishnan, Unoh Kwon
  • Publication number: 20160163603
    Abstract: A method of forming a transistor device includes forming an interfacial layer and a dielectric layer over a substrate; and forming a p-type field effect transistor (PFET) workfunction metal layer over the dielectric layer, the workfunction metal layer comprising a lower titanium nitride (TiN) first layer and a second layer including one of titanium-aluminum-carbide (TiAlC) and tantalum-aluminum-carbide (TaAlC) formed on the lower TiN first layer.
    Type: Application
    Filed: December 8, 2014
    Publication date: June 9, 2016
    Inventors: Ruqiang Bao, Siddarth Krishnan, Unoh Kwon, Keith Kwong Hon Wong
  • Patent number: 9330938
    Abstract: A method of fabricating advanced node field effect transistors using a replacement metal gate process. The method includes dopant a high-k dielectric directly or indirectly by using layers composed of multi-layer thin film stacks, or in other embodiments, by a single blocking layer. By taking advantage of unexpected etch selectivity of the multi-layer stack or the controlled etch process of a single layer stack, etch damage to the high-k may be avoided and work function metal thicknesses can be tightly controlled which in turn allows field effect transistors with low Tinv (inverse of gate capacitance) mismatch.
    Type: Grant
    Filed: July 24, 2014
    Date of Patent: May 3, 2016
    Assignee: International Business Machines Corporation
    Inventors: Takashi Ando, Hemanth Jagannathan, Balaji Kannan, Siddarth A. Krishnan, Unoh Kwon, Rekha Rajaram
  • Patent number: 9318336
    Abstract: A high dielectric constant (high-k) gate dielectric for a field effect transistor (FET) and a high-k tunnel dielectric for a non-volatile random access memory (NVRAM) device are simultaneously formed on a semiconductor substrate. A stack of at least one conductive material layer, a control gate dielectric layer, and a disposable material layer is subsequently deposited and lithographically patterned. A planarization dielectric layer is deposited and patterned, and disposable material portions are removed. A remaining portion of the control gate dielectric layer is preserved in the NVRAM device region, but is removed in the FET region. A conductive material is deposited in gate cavities to provide a control gate for the NVRAM device and a gate portion for the FET. Alternately, the control gate dielectric layer may replaced with a high-k control gate dielectric in the NVRAM device region.
    Type: Grant
    Filed: December 15, 2011
    Date of Patent: April 19, 2016
    Assignee: GLOBALFOUNDRIES U.S. 2 LLC
    Inventors: Nicolas Breil, Michael P. Chudzik, Rishikesh Krishnan, Siddarth A. Krishnan, Unoh Kwon
  • Publication number: 20160086849
    Abstract: In-situ melting and crystallization of sealed cooper wires can be performed by means of laser annealing for a duration of nanoseconds. The intensity of the laser irradiation is selected such that molten copper wets interconnect interfaces, thereby forming an interfacial bonding arrangement that increases specular scattering of electrons. Nanosecond-scale temperature quenching preserves the formed interfacial bonding. At the same time, the fast crystallization process of sealed copper interconnects results in large copper grains, typically larger than 80 nm in lateral dimensions, on average. A typical duration of the annealing process is from about 10's to about 100's of nanoseconds. There is no degradation to interlayer low-k dielectric material despite the high anneal temperature due to ultra short duration that prevents collective motion of atoms within the dielectric material.
    Type: Application
    Filed: September 19, 2014
    Publication date: March 24, 2016
    Inventors: Oleg Gluschenkov, Siddarth A. Krishnan, Joyeeta Nag, Andrew H. Simon, Shishir Ray
  • Publication number: 20160049337
    Abstract: A method of fabricating advanced node field effect transistors using a replacement metal gate process. The method includes dopant a high-k dielectric directly or indirectly by using layers composed of multi-layer thin film stacks, or in other embodiments, by a single blocking layer. By taking advantage of unexpected etch selectivity of the multi-layer stack or the controlled etch process of a single layer stack, etch damage to the high-k may be avoided and work function metal thicknesses can be tightly controlled which in turn allows field effect transistors with low Tinv (inverse of gate capacitance) mismatch.
    Type: Application
    Filed: October 22, 2015
    Publication date: February 18, 2016
    Inventors: Takashi Ando, Hemanth Jagannathan, Balaji Kannan, Siddarth A. Krishnan, Unoh Kwon, Rekha Rajaram
  • Publication number: 20160027664
    Abstract: A method of fabricating advanced node field effect transistors using a replacement metal gate process. The method includes dopant a high-k dielectric directly or indirectly by using layers composed of multi-layer thin film stacks, or in other embodiments, by a single blocking layer. By taking advantage of unexpected etch selectivity of the multi-layer stack or the controlled etch process of a single layer stack, etch damage to the high-k may be avoided and work function metal thicknesses can be tightly controlled which in turn allows field effect transistors with low Tiny (inverse of gate capacitance) mismatch.
    Type: Application
    Filed: July 24, 2014
    Publication date: January 28, 2016
    Inventors: Takashi Ando, Hemanth Jagannathan, Balaji Kannan, Siddarth A. Krishnan, Unoh Kwon, Rekha Rajaram
  • Publication number: 20160005831
    Abstract: Selective deposition of a silicon-germanium surface layer on semiconductor surfaces can be employed to provide two types of channel regions for field effect transistors. Anneal of an adjustment oxide material on a stack of a silicon-based gate dielectric and a high dielectric constant (high-k) gate dielectric can be employed to form an interfacial adjustment oxide layer contacting a subset of channel regions. Oxygen deficiency can be induced in portions of the high-k dielectric layer overlying the interfacial adjustment oxide layer by deposition of a first work function metallic material layer and a capping layer and a subsequent anneal. Oxygen deficiency can be selectively removed by physically exposing portions of the high-k dielectric layer. A second work function metallic material layer and a gate conductor layer can be deposited and planarized to form gate electrodes that provide multiple effective work functions.
    Type: Application
    Filed: July 1, 2014
    Publication date: January 7, 2016
    Applicant: International Business Machines Corporation
    Inventors: Takashi Ando, Min Dai, Balaji Kannan, Siddarth A. Krishnan, Unoh Kwon
  • Publication number: 20150349076
    Abstract: A method of forming a semiconductor device includes forming first and second semiconductor structures on a semiconductor substrate. The first semiconductor structure includes a first gate channel region having a first gate length, and the second semiconductor structure including a second gate channel region having a second gate length that is greater than the first gate length. The method further includes depositing a work function metal layer in each of a first gate void formed at the first gate channel region and a second gate void formed at the second gate channel region. The method further includes depositing a semiconductor masking layer on the work function metal layer, and simultaneously etching the silicon masking layer located at the first and second gate channel regions to re-expose the first and second gate voids. A low-resistive metal is deposited in the first and second gate voids to form low-resistive metal gate stacks.
    Type: Application
    Filed: August 14, 2015
    Publication date: December 3, 2015
    Inventors: Michael P. Chudzik, Siddarth A. Krishnan, Unoh Kwon
  • Publication number: 20150255463
    Abstract: A method for forming a replacement metal gate structure sharing a single work function metal for both the N-FET and the P-FET gates. The method oppositely dopes a high-k material of the N-FET and P-FET gate, respectively, using a single lithography step. The doping allows use of a single work function metal which in turn provides more space in the metal gate opening so that a bulk fill material may occupy more volume of the opening resulting in a lower resistance gate.
    Type: Application
    Filed: March 6, 2014
    Publication date: September 10, 2015
    Applicant: International Business Machines Corporation
    Inventors: Takashi Ando, Balaji Kannan, Siddarth Krishnan, Unoh Kwon, Shahab Siddiqui
  • Patent number: 9099394
    Abstract: A high dielectric constant (high-k) gate dielectric for a field effect transistor (FET) and a high-k tunnel dielectric for a non-volatile random access memory (NVRAM) device are simultaneously formed on a semiconductor substrate. A stack of at least one conductive material layer, a control gate dielectric layer, and a disposable material layer is subsequently deposited and lithographically patterned. A planarization dielectric layer is deposited and patterned, and disposable material portions are removed. A remaining portion of the control gate dielectric layer is preserved in the NVRAM device region, but is removed in the FET region. A conductive material is deposited in gate cavities to provide a control gate for the NVRAM device and a gate portion for the FET. Alternately, the control gate dielectric layer may replaced with a high-k control gate dielectric in the NVRAM device region.
    Type: Grant
    Filed: October 29, 2013
    Date of Patent: August 4, 2015
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Nicolas Breil, Michael P. Chudzik, Rishikesh Krishnan, Siddarth A. Krishnan, Unoh Kwon
  • Patent number: 9087722
    Abstract: A method of manufacturing multiple finFET devices having different thickness gate oxides. The method may include depositing a first dielectric layer on top of the semiconductor substrate, on top of a first fin, and on top of a second fin; forming a first dummy gate stack; forming a second dummy gate stack; removing the first and second dummy gates selective to the first and second gate oxides; masking a portion of the semiconductor structure comprising the second fin, and removing the first gate oxide from atop the first fin; and depositing a second dielectric layer within the first opening, and within the second opening, the second dielectric layer being located on top of the first fin and adjacent to the exposed sidewalls of the first pair of dielectric spacers, and on top of the second gate oxide and adjacent to the exposed sidewalls of the second pair of dielectric spacers.
    Type: Grant
    Filed: November 14, 2014
    Date of Patent: July 21, 2015
    Assignee: International Business Machines Corporation
    Inventors: Charlotte D. Adams, Michael P. Chudzik, Siddarth A. Krishnan, Unoh Kwon, Shahab Siddiqui
  • Patent number: 9087927
    Abstract: A trench structure that in one embodiment includes a trench present in a substrate, and a dielectric layer that is continuously present on the sidewalls and base of the trench. The dielectric layer has a dielectric constant that is greater than 30. The dielectric layer is composed of tetragonal phase hafnium oxide with silicon present in the grain boundaries of the tetragonal phase hafnium oxide in an amount ranging from 3 wt. % to 20 wt. %.
    Type: Grant
    Filed: October 23, 2014
    Date of Patent: July 21, 2015
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Michael P. Chudzik, Bachir Dirahoui, Rishikesh Krishnan, Siddarth A. Krishnan, Oh-jung Kwon, Paul C. Parries, Hongwen Yan
  • Patent number: 9087784
    Abstract: A complementary metal oxide semiconductor (CMOS) structure including a scaled n-channel field effect transistor (nFET) and a scaled p-channel field transistor (pFET) is provided. Such a structure is provided by forming a plasma nitrided, nFET threshold voltage adjusted high k gate dielectric layer portion within an nFET gate stack, and forming at least a pFET threshold voltage adjusted high k gate dielectric layer portion within a pFET gate stack. The pFET threshold voltage adjusted high k gate dielectric layer portion in the pFET gate stack may also plasma nitrided. The plasma nitrided, nFET threshold voltage adjusted high k gate dielectric layer portion includes up to 15 atomic % N2 and an nFET threshold voltage adjusted species located therein.
    Type: Grant
    Filed: January 29, 2014
    Date of Patent: July 21, 2015
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Michael P. Chudzik, Dechao Guo, Siddarth A. Krishnan, Unoh Kwon, Carl J. Radens, Shahab Siddiqui
  • Patent number: 9059315
    Abstract: Embodiments include methods of forming an nFET-tuned gate dielectric and a pFET-tuned gate dielectric. Methods may include forming a high-k layer above a substrate having a pFET region and an nFET region, forming a first sacrificial layer, a pFET work-function metal layer, and a second sacrificial layer above the first high-k layer in the pFET region, and an nFET work-function metal layer above the first high-k layer in the nFET region and above the second sacrificial layer in the pFET region. The first high-k layer then may be annealed to form an nFET gate dielectric layer in the nFET region and a pFET gate dielectric layer in the pFET region. The first high-k layer may be annealed in the presence of a nitrogen source to cause atoms from the nitrogen source to diffuse into the first high-k layer in the nFET region.
    Type: Grant
    Filed: January 2, 2013
    Date of Patent: June 16, 2015
    Assignees: International Business Machines Corporation, GLOBALFOUNDRIES, Inc.
    Inventors: Takashi Ando, Maryjane Brodsky, Michael P. Chudzik, Min Dai, Siddarth A. Krishnan, Joseph F. Shepard, Jr., Yanfeng Wang, Jinping Liu
  • Publication number: 20150145062
    Abstract: A method of forming a semiconductor device includes forming first and second semiconductor structures on a semiconductor substrate. The first semiconductor structure includes a first gate channel region having a first gate length, and the second semiconductor structure including a second gate channel region having a second gate length that is greater than the first gate length. The method further includes depositing a work function metal layer in each of a first gate void formed at the first gate channel region and a second gate void formed at the second gate channel region. The method further includes depositing a semiconductor masking layer on the work function metal layer, and simultaneously etching the silicon masking layer located at the first and second gate channel regions to re-expose the first and second gate voids. A low-resistive metal is deposited in the first and second gate voids to form low-resistive metal gate stacks.
    Type: Application
    Filed: November 25, 2013
    Publication date: May 28, 2015
    Applicant: International Business Machines Corporation
    Inventors: Michael P. Chudzik, Siddarth A. Krishnan, Unoh Kwon
  • Patent number: 9006837
    Abstract: A complementary metal oxide semiconductor structure including a scaled 0 and a scaled pFET which do not exhibit an increased threshold voltage and reduced mobility during operation is provided. The method includes forming a plasma nitrided, nFET threshold voltage adjusted high k gate dielectric layer portion within an nFET gate stack, and forming at least a pFET threshold voltage adjusted high k gate dielectric layer portion within a pFET gate stack. The pFET threshold voltage adjusted high k gate dielectric layer portion in the pFET gate stack can also be plasma nitrided. The plasma nitrided, nFET threshold voltage adjusted high k gate dielectric layer portion contains up to 15 atomic % N2 and an nFET threshold voltage adjusted species, while the plasma nitrided, pFET threshold voltage adjusted high k gate dielectric layer portion contains up to 15 atomic % N2 and a pFET threshold voltage adjusted species.
    Type: Grant
    Filed: March 11, 2013
    Date of Patent: April 14, 2015
    Assignee: International Business Machines Corporation
    Inventors: Michael P. Chudzik, Dechao Guo, Siddarth A. Krishnan, Unoh Kwon, Carl J. Radens, Shahab Siddiqui
  • Publication number: 20150069525
    Abstract: A method of manufacturing multiple finFET devices having different thickness gate oxides. The method may include depositing a first dielectric layer on top of the semiconductor substrate, on top of a first fin, and on top of a second fin; forming a first dummy gate stack; forming a second dummy gate stack; removing the first and second dummy gates selective to the first and second gate oxides; masking a portion of the semiconductor structure comprising the second fin, and removing the first gate oxide from atop the first fin; and depositing a second dielectric layer within the first opening, and within the second opening, the second dielectric layer being located on top of the first fin and adjacent to the exposed sidewalls of the first pair of dielectric spacers, and on top of the second gate oxide and adjacent to the exposed sidewalls of the second pair of dielectric spacers.
    Type: Application
    Filed: November 14, 2014
    Publication date: March 12, 2015
    Inventors: Charlotte D. Adams, Michael P. Chudzik, Siddarth A. Krishnan, Unoh Kwon, Shahab Siddiqui
  • Publication number: 20150044853
    Abstract: A trench structure that in one embodiment includes a trench present in a substrate, and a dielectric layer that is continuously present on the sidewalls and base of the trench. The dielectric layer has a dielectric constant that is greater than 30. The dielectric layer is composed of tetragonal phase hafnium oxide with silicon present in the grain boundaries of the tetragonal phase hafnium oxide in an amount ranging from 3 wt. % to 20 wt. %.
    Type: Application
    Filed: October 23, 2014
    Publication date: February 12, 2015
    Inventors: Michael P. Chudzik, Bachir Dirahoui, Rishikesh Krishnan, Siddarth A. Krishnan, Oh-jung Kwon, Paul C. Parries, Hongwen Yan