Patents by Inventor Rajasekhar Venigalla

Rajasekhar Venigalla 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: 10388757
    Abstract: A method of fabricating a vertical field effect transistor including forming a first recess in a substrate; epitaxially growing a first drain from the first bottom surface of the first recess; epitaxially growing a second drain from the second bottom surface of a second recess formed in the substrate; growing a channel material epitaxially on the first drain and the second drain; forming troughs in the channel material to form one or more fin channels on the first drain and one or more fin channels on the second drain, wherein the troughs over the first drain extend to the surface of the first drain, and the troughs over the second drain extend to the surface of the second drain; forming a gate structure on each of the one or more fin channels; and growing sources on each of the fin channels associated with the first and second drains.
    Type: Grant
    Filed: May 25, 2017
    Date of Patent: August 20, 2019
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Brent A. Anderson, Bruce B. Doris, Seong-Dong Kim, Rajasekhar Venigalla
  • Patent number: 10381463
    Abstract: Embodiments are directed to a method and resulting structures for smoothing the sidewall roughness of a post-etched film. A sacrificial layer is formed on a substrate. A patterned mask is formed by removing portions of the sacrificial layer to expose a surface of the substrate. The sidewalls of the patterned mask are smoothed and a target layer is formed over the patterned mask and the substrate. Portions of the target layer are removed to expose a surface of the patterned mask and the patterned mask is removed.
    Type: Grant
    Filed: January 19, 2018
    Date of Patent: August 13, 2019
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Kafai Lai, Hari V. Mallela, Hiroyuki Miyazoe, Reinaldo A. Vega, Rajasekhar Venigalla
  • Patent number: 10283416
    Abstract: A method of forming a variable spacer in a vertical transistor device includes forming a first source/drain of a first transistor on a substrate; forming a second source/drain of a second transistor on the substrate adjacent to the first source/drain, an isolation region arranged in the substrate between the first source/drain and the second source/drain; depositing a spacer material on the first source/drain; depositing the spacer material on the second source/drain; forming a first channel extending from the first source drain and through the spacer material; forming a second channel extending from the second source/drain and through the spacer material; wherein the spacer material on the first source/drain forms a first spacer and the spacer material on the second source/drain forms a second spacer, the first spacer being different in thickness than the second spacer.
    Type: Grant
    Filed: January 12, 2018
    Date of Patent: May 7, 2019
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Hari V. Mallela, Reinaldo A. Vega, Rajasekhar Venigalla
  • Patent number: 10256238
    Abstract: A method of forming a semiconductor structure includes forming a fin cut mask over a region in a fin field-effect transistor (finFET) structure. The finFET structure includes one or more fins and one or more gates and source/drain regions formed over the one or more fins in active regions of the finFET structure. The method also includes performing a fin cut by removing a portion of at least one fin. The portion of the at least one fin is determined by an exposed area of the fin cut mask. The exposed area of the fin cut mask includes at least a portion of the at least one fin between a first dummy gate and a second dummy gate formed over the at least one fin. The method further includes removing the fin cut mask and depositing an oxide to replace the portion of the at least one fin removed during the fin cut.
    Type: Grant
    Filed: July 18, 2018
    Date of Patent: April 9, 2019
    Assignee: International Business Machines Corporation
    Inventors: Andrew M. Greene, Dechao Guo, Ravikumar Ramachandran, Rajasekhar Venigalla
  • Patent number: 10242918
    Abstract: A dual layer shallow isolation trench region for semiconductor structures including field effect transistors (FETs) and methods for making the same. The first layer of the shallow trench isolation region includes a dielectric material disposed between adjacent FETs. The second layer is an etch resistant material disposed on the dielectric material and has an increased etch resistance relative to the dielectric material. The etch resistant material overlays the shallow trench region to provide the dual layer shallow trench isolation region, which permits self-alignment of contacts to the source and/or drain of FETs.
    Type: Grant
    Filed: February 8, 2017
    Date of Patent: March 26, 2019
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Andrew M. Greene, Ravikumar Ramachandran, Rajasekhar Venigalla
  • Patent number: 10243041
    Abstract: A fin field effect transistor device with air gaps, including a source/drain layer on a substrate, one or more vertical fin(s) in contact with source/drain layer, a gate metal fill that forms a portion of a gate structure on each of the one or more vertical fin(s), and a bottom void space between the source/drain layer and the gate metal fill.
    Type: Grant
    Filed: June 19, 2017
    Date of Patent: March 26, 2019
    Assignee: International Business Machines Corporation
    Inventors: Hari V. Mallela, Robert R. Robison, Reinaldo A. Vega, Rajasekhar Venigalla
  • Patent number: 10211207
    Abstract: A method for fabricating a semiconductor device includes accessing source/drain regions (S/D) in an n-type field effect transistor (NFET) region and in a p-type field effect transistor (PFET) region. First alloy elements are implanted in the S/D regions in the NFET region, and second alloy elements are implanted in the PFET region with the NFET region blocked. The first and second alloy elements form respective amorphized layers on the S/D regions in respective NFET and PFET regions. The amorphized layers are recrystallized to form metastable recrystallized interfaces using an epitaxy process wherein the metastable recrystallized interfaces formed in respective NFET and PFET regions exceed solubility of the first and second alloy elements in respective materials of the S/D regions in the NFET and PFET regions. Contacts to the metastable recrystallized layers of the S/D regions in the NFET and PFET regions are concurrently formed.
    Type: Grant
    Filed: March 7, 2018
    Date of Patent: February 19, 2019
    Assignee: International Business Machines Corporation
    Inventors: Praneet Adusumilli, Oleg Gluschenkov, Dechao Guo, Zuoguang Liu, Rajasekhar Venigalla, Tenko Yamashita
  • Publication number: 20190027557
    Abstract: A fin field effect transistor device with air gaps, including a source/drain layer on a substrate, one or more vertical fin(s) in contact with source/drain layer, a gate metal fill that forms a portion of a gate structure on each of the one or more vertical fin(s), and a bottom void space between the source/drain layer and the gate metal fill.
    Type: Application
    Filed: September 25, 2018
    Publication date: January 24, 2019
    Inventors: Hari V. Mallela, Robert R. Robison, Reinaldo A. Vega, Rajasekhar Venigalla
  • Patent number: 10177167
    Abstract: A method for forming a hybrid complementary metal oxide semiconductor (CMOS) device includes orienting a semiconductor layer of a semiconductor-on-insulator (SOI) substrate with a base substrate of the SOI, exposing the base substrate in an N-well region by etching through a mask layer, a dielectric layer, the semiconductor layer and a buried dielectric to form a trench and forming spacers on sidewalls of the trench. The base substrate is epitaxially grown from a bottom of the trench to form an extended region. A fin material is epitaxially grown from the extended region within the trench. The mask layer and the dielectric layer are restored over the trench. P-type field-effect transistor (PFET) fins are etched on the base substrate, and N-type field-effect transistor (NFET) fins are etched in the semiconductor layer.
    Type: Grant
    Filed: July 6, 2016
    Date of Patent: January 8, 2019
    Assignee: International Business Machines Corporation
    Inventors: Chia-Yu Chen, Bruce B. Doris, Hong He, Rajasekhar Venigalla
  • Patent number: 10177039
    Abstract: A dual layer shallow isolation trench region for semiconductor structures including field effect transistors (FETs) and methods for making the same. The first layer of the shallow trench isolation region includes a dielectric material disposed between adjacent FETs. The second layer is an etch resistant material disposed on the dielectric material and has an increased etch resistance relative to the dielectric material. The etch resistant material overlays the shallow trench region to provide the dual layer shallow trench isolation region, which permits self-alignment of contacts to the source and/or drain of FETs.
    Type: Grant
    Filed: November 6, 2017
    Date of Patent: January 8, 2019
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Andrew M. Greene, Ravikumar Ramachandran, Rajasekhar Venigalla
  • Patent number: 10170543
    Abstract: A fin field effect transistor device with air gaps, including a source/drain layer on a substrate, one or more vertical fin(s) in contact with source/drain layer, a gate metal fill that forms a portion of a gate structure on each of the one or more vertical fin(s), and a bottom void space between the source/drain layer and the gate metal fill.
    Type: Grant
    Filed: October 25, 2017
    Date of Patent: January 1, 2019
    Assignee: International Business Machines Corporation
    Inventors: Hari V. Mallela, Robert R. Robison, Reinaldo A. Vega, Rajasekhar Venigalla
  • Patent number: 10170485
    Abstract: A structure comprises a first channel region forming an n-channel device; a second channel region forming a p-channel device, the p-channel device being stacked with the n-channel device in a vertical orientation; a gate positioned around the stacked n-channel device and p-channel device; and at least one source region and at least one drain region extending from each of the n-channel device and the p-channel device. Each of the at least one source region and the at least one drain region within the stacked n-channel device and p-channel device are independently contacted.
    Type: Grant
    Filed: June 18, 2018
    Date of Patent: January 1, 2019
    Assignee: International Business Machines Corporation
    Inventors: Michael A. Guillorn, Robert R. Robison, Reinaldo Vega, Rajasekhar Venigalla
  • Patent number: 10170584
    Abstract: A method of forming a nanosheet device, including forming a channel stack on a substrate, where the channel stack includes at least one nanosheet channel layer and at least one sacrificial release layer, forming a stack cover layer on at least a portion of the channel stack, forming a dummy gate on at least a portion of the stack cover layer, wherein at least a portion of the at least one nanosheet channel layer and at least one sacrificial release layer is exposed on opposite sides of the dummy gate, removing at least a portion of the at least one sacrificial release layer on each side of the dummy gate to form a sacrificial supporting rib, and forming an inner spacer layer on exposed portions of the at least one nanosheet channel layer and at least one sacrificial supporting rib.
    Type: Grant
    Filed: January 27, 2017
    Date of Patent: January 1, 2019
    Assignee: International Business Machines Corporation
    Inventors: Michael A. Guillorn, Terence B. Hook, Robert R. Robison, Reinaldo A. Vega, Rajasekhar Venigalla
  • Patent number: 10164119
    Abstract: A method of fabricating a vertical field effect transistor comprising that includes forming openings through a spacer material to provide fin structure openings to a first semiconductor material, and forming an inner spacer liner on sidewalls of the fin structure openings. A channel semiconductor material is epitaxially formed on a surface of the first semiconductor material filling at least a portion of the fin structure openings. The spacer material is recessed with an etch that is selective to the inner spacer liner to form a first spacer. The inner spacer liner is removed selectively to the channel semiconductor material. A gate structure on the channel semiconductor material, and a second semiconductor material is formed in contact with the channel semiconductor material.
    Type: Grant
    Filed: May 9, 2017
    Date of Patent: December 25, 2018
    Assignee: International Business Machines Corporation
    Inventors: Hari V. Mallela, Reinaldo A. Vega, Rajasekhar Venigalla
  • Publication number: 20180350810
    Abstract: A method of forming a power rail to semiconductor devices comprising removing a portion of the gate structure forming a gate cut trench separating a first active region of fin structures from a second active region of fin structures. A conformal etch stop layer is formed in the gate cut trench. A fill material is formed on the conformal etch stop layer filling at least a portion of the gate cut trench. The fill material has a composition that is etched selectively to the conformal etch stop layer. A power rail is formed in the gate cut trench. The conformal etch stop layer obstructs lateral etching during forming the power rail to substantially eliminate power rail to gate structure shorting.
    Type: Application
    Filed: August 3, 2018
    Publication date: December 6, 2018
    Inventors: Marc A. Bergendahl, Andrew M. Greene, Rajasekhar Venigalla
  • Publication number: 20180342512
    Abstract: A method of forming a power rail to semiconductor devices comprising removing a portion of the gate structure forming a gate cut trench separating a first active region of fin structures from a second active region of fin structures. A conformal etch stop layer is formed in the gate cut trench. A fill material is formed on the conformal etch stop layer filling at least a portion of the gate cut trench. The fill material has a composition that is etched selectively to the conformal etch stop layer. A power rail is formed in the gate cut trench. The conformal etch stop layer obstructs lateral etching during forming the power rail to substantially eliminate power rail to gate structure shorting.
    Type: Application
    Filed: August 3, 2018
    Publication date: November 29, 2018
    Inventors: Marc A. Bergendahl, Andrew M. Greene, Rajasekhar Venigalla
  • Publication number: 20180342525
    Abstract: A structure comprises a first channel region forming an n-channel device; a second channel region forming a p-channel device, the p-channel device being stacked with the n-channel device in a vertical orientation; a gate positioned around the stacked n-channel device and p-channel device; and at least one source region and at least one drain region extending from each of the n-channel device and the p-channel device. Each of the at least one source region and the at least one drain region within the stacked n-channel device and p-channel device are independently contacted.
    Type: Application
    Filed: June 18, 2018
    Publication date: November 29, 2018
    Inventors: Michael A. Guillorn, Robert R. Robison, Reinaldo Vega, Rajasekhar Venigalla
  • Patent number: 10141308
    Abstract: A method for fabricating a semiconductor device includes accessing source/drain regions (S/D) in an n-type field effect transistor (NFET) region and in a p-type field effect transistor (PFET) region. First alloy elements are implanted in the S/D regions in the NFET region, and second alloy elements are implanted in the PFET region with the NFET region blocked. The first and second alloy elements form respective amorphized layers on the S/D regions in respective NFET and PFET regions. The amorphized layers are recrystallized to form metastable recrystallized interfaces using an epitaxy process wherein the metastable recrystallized interfaces formed in respective NFET and PFET regions exceed solubility of the first and second alloy elements in respective materials of the S/D regions in the NFET and PFET regions. Contacts to the metastable recrystallized layers of the S/D regions in the NFET and PFET regions are concurrently formed.
    Type: Grant
    Filed: March 10, 2017
    Date of Patent: November 27, 2018
    Assignee: International Business Machines Corporation
    Inventors: Praneet Adusumilli, Oleg Gluschenkov, Dechao Guo, Zuoguang Liu, Rajasekhar Venigalla, Tenko Yamashita
  • Patent number: 10128239
    Abstract: A method of forming a semiconductor structure includes forming a fin cut mask over a region in a fin field-effect transistor (finFET) structure. The finFET structure includes one or more fins and one or more gates and source/drain regions formed over the one or more fins in active regions of the finFET structure. The method also includes performing a fin cut by removing a portion of at least one fin. The portion of the at least one fin is determined by an exposed area of the fin cut mask. The exposed area of the fin cut mask includes at least a portion of the at least one fin between a first dummy gate and a second dummy gate formed over the at least one fin. The method further includes removing the fin cut mask and depositing an oxide to replace the portion of the at least one fin removed during the fin cut.
    Type: Grant
    Filed: October 17, 2016
    Date of Patent: November 13, 2018
    Assignee: International Business Machines Corporation
    Inventors: Andrew M. Greene, Dechao Guo, Ravikumar Ramachandran, Rajasekhar Venigalla
  • Publication number: 20180323193
    Abstract: A method of forming a semiconductor structure includes forming a fin cut mask over a region in a fin field-effect transistor (finFET) structure. The finFET structure includes one or more fins and one or more gates and source/drain regions formed over the one or more fins in active regions of the finFET structure. The method also includes performing a fin cut by removing a portion of at least one fin. The portion of the at least one fin is determined by an exposed area of the fin cut mask. The exposed area of the fin cut mask includes at least a portion of the at least one fin between a first dummy gate and a second dummy gate formed over the at least one fin. The method further includes removing the fin cut mask and depositing an oxide to replace the portion of the at least one fin removed during the fin cut.
    Type: Application
    Filed: July 18, 2018
    Publication date: November 8, 2018
    Inventors: Andrew M. Greene, Dechao Guo, Ravikumar Ramachandran, Rajasekhar Venigalla