Patents by Inventor Prasanna Khare

Prasanna Khare 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: 9000555
    Abstract: An electronic device may include a substrate, a buried oxide (BOX) layer overlying the substrate, at least one semiconductor device overlying the BOX layer, and at least one STI region in the substrate and adjacent the at least one semiconductor device. The at least one STI region defines a sidewall surface with the substrate and may include a nitride layer lining a bottom portion of the sidewall surface, an oxide layer lining a top portion of the sidewall surface above the bottom portion, and an insulating material within the nitride and oxide layers.
    Type: Grant
    Filed: August 21, 2012
    Date of Patent: April 7, 2015
    Assignee: STMicroelectronics, Inc.
    Inventors: Qing Liu, Nicolas Loubet, Prasanna Khare
  • Patent number: 9000491
    Abstract: Insulating layers can be formed over a semiconductor device region and etched in a manner that substantially reduces or prevents the amount of etching of the underlying channel region. A first insulating layer can be formed over a gate region and a semiconductor device region. A second insulating layer can be formed over the first insulating layer. A third insulating layer can be formed over the second insulating layer. A portion of the third insulating layer can be etched using a first etching process. A portion of the first and second insulating layers beneath the etched portion of the third insulating layer can be etched using at least a second etching process different from the first etching process.
    Type: Grant
    Filed: June 19, 2014
    Date of Patent: April 7, 2015
    Assignee: STMicroelectronics, Inc.
    Inventors: Nicolas Loubet, Qing Liu, Prasanna Khare
  • Publication number: 20150093861
    Abstract: An SOI substrate includes first and second active regions separated by STI structures and including gate stacks. A spacer layer conformally deposited over the first and second regions including the gate stacks is directionally etched to define sidewall spacers along the sides of the gate stacks. An oxide layer and nitride layer are then deposited. Using a mask, the nitride layer over the first active region is removed, and the mask and oxide layer are removed to expose the SOI substrate in the first active region. Raised source-drain structures are then epitaxially grown adjacent the gate stacks in the first active region and a protective nitride layer is deposited. The masking, nitride layer removal, and oxide layer removal steps are then repeated to expose the SOI in the second active region. Raised source-drain structures are then epitaxially grown adjacent the gate stacks in the second active region.
    Type: Application
    Filed: October 1, 2013
    Publication date: April 2, 2015
    Applicant: STMICROELECTRONICS, INC.
    Inventors: Nicolas Loubet, Qing Liu, Prasanna Khare
  • Patent number: 8987082
    Abstract: A method of making a semiconductor device includes forming a sacrificial layer above a semiconductor layer. Portions of the sacrificial layer are selectively removed to define a first set of spaced apart sacrificial fins over a first region of the semiconductor layer, and a second set of spaced apart sacrificial fins over a second region of the semiconductor layer. An isolation trench is formed in the semiconductor layer between the first and second regions. The isolation trench and spaces are filled with a dielectric material. The first and second sets of sacrificial fins are removed to define respective first and second sets of fin openings. The first set of fin openings is filled to define a first set of semiconductor fins for a first conductivity-type transistor, and the second set of fin openings is filled to define a second set of semiconductor fins for a second conductivity-type transistor.
    Type: Grant
    Filed: May 31, 2013
    Date of Patent: March 24, 2015
    Assignee: STMicroelectronics, Inc.
    Inventors: Nicolas Loubet, Prasanna Khare
  • Patent number: 8956942
    Abstract: Channel-to-substrate leakage in a FinFET device is prevented by inserting an insulating layer between the semiconducting channel (fin) and the substrate during fabrication of the device. Similarly, source/drain-to-substrate leakage in a FinFET device is prevented by isolating the source/drain regions from the substrate by inserting an insulating layer between the source/drain regions and the substrate. Forming such an insulating layer isolates the conduction path from the substrate both physically and electrically, thus preventing current leakage. In an array of semiconducting fins made up of a multi-layer stack, the bottom material is removed, thus yielding a fin array that is suspended above the silicon surface. A resulting gap underneath the remaining top fin material is then filled with oxide to better support the fins and to isolate the array of fins from the substrate.
    Type: Grant
    Filed: December 21, 2012
    Date of Patent: February 17, 2015
    Assignee: STMicroelectronics, Inc.
    Inventors: Nicolas Loubet, Prasanna Khare
  • Publication number: 20150041898
    Abstract: Methods and structures for forming fully insulated finFETs beginning with a bulk semiconductor substrate are described. Fin structures for finFETs may be formed in two epitaxial layers that are grown over a bulk substrate. A first epitaxial layer may be sacrificial. A final gate structure may be formed around the fin structures, and the first epitaxial layer removed to form a void between a fin and the substrate. The void may be filled with an insulator to fully insulate the fin.
    Type: Application
    Filed: August 9, 2013
    Publication date: February 12, 2015
    Applicants: GLOBALFOUNDRIES Inc., STMicroelectronics, Inc.
    Inventors: Nicolas Loubet, Prasanna Khare, Jin Cho
  • Publication number: 20150021690
    Abstract: Methods and semiconductor structures formed from the methods are provided which facilitate fabricating semiconductor fin structures. The methods include, for example: providing a wafer with at least one semiconductor fin extending above a substrate; transforming a portion of the semiconductor fin(s) into an isolation layer, the isolation layer separating a semiconductor layer of the semiconductor fin(s) from the substrate; and proceeding with forming a fin device(s) of a first architectural type in a first fin region of the semiconductor fin(s), and a fin device(s) of a second architectural type in a second fin region of the semiconductor fin(s), where the first architectural type and the second architectural type are different fin device architectures.
    Type: Application
    Filed: July 18, 2013
    Publication date: January 22, 2015
    Inventors: Ajey Poovannummoottil JACOB, Kangguo CHENG, Bruce B. DORIS, Nicolas LOUBET, Prasanna KHARE, Ramachandra DIVAKARUNI
  • Publication number: 20150024572
    Abstract: Semiconductor fabrication methods are provided which include facilitating fabricating semiconductor fin structures by: providing a wafer with at least one fin extending above a substrate, the at least one fin including a first layer disposed above a second layer; mechanically stabilizing the first layer; removing at least a portion of the second layer of the fin(s) to create a void below the first layer; filling the void, at least partially, below the first layer with an isolation material to create an isolation layer within the fin(s); and proceeding with forming a fin device(s) of a first architectural type in a first fin region of the fin(s), and a fin device(s) of a second architectural type in a second fin region of the fin(s), where the first architectural type and the second architectural type are different fin device architectures.
    Type: Application
    Filed: July 18, 2013
    Publication date: January 22, 2015
    Inventors: Ajey P. JACOB, Kangguo CHENG, Bruce B. DORIS, Nicolas LOUBET, Prasanna KHARE, Ramachandra DIVAKARUNI
  • Publication number: 20150008521
    Abstract: A transistor includes a body and a semiconductor region configured to stress a portion of the body. For example, stressing a channel of the transistor may increase the mobility of carriers in the channel, and thus may reduce the “on” resistance of the transistor. For example, the substrate, source/drain regions, or both the substrate and source/drain regions of a PFET may be doped to compressively stress the channel so as to increase the mobility of holes in the channel. Or, the substrate, source/drain regions, or both the substrate and source/drain regions of an NFET may be doped to tensile stress the channel so as to increase the mobility of electrons in the channel.
    Type: Application
    Filed: September 24, 2014
    Publication date: January 8, 2015
    Applicant: STMICROELECTRONICS, INC.
    Inventors: Nicolas Loubet, Prasanna Khare, Qing Liu
  • Publication number: 20140357029
    Abstract: A method of making a semiconductor device includes forming a sacrificial layer above a semiconductor layer. Portions of the sacrificial layer are selectively removed to define a first set of spaced apart sacrificial fins over a first region of the semiconductor layer, and a second set of spaced apart sacrificial fins over a second region of the semiconductor layer. An isolation trench is formed in the semiconductor layer between the first and second regions. The isolation trench and spaces are filled with a dielectric material. The first and second sets of sacrificial fins are removed to define respective first and second sets of fin openings. The first set of fin openings is filled to define a first set of semiconductor fins for a first conductivity-type transistor, and the second set of fin openings is filled to define a second set of semiconductor fins for a second conductivity-type transistor.
    Type: Application
    Filed: May 31, 2013
    Publication date: December 4, 2014
    Inventors: NICOLAS LOUBET, Prasanna Khare
  • Publication number: 20140353760
    Abstract: A method for co-integrating finFETs of two semiconductor material types, e.g., Si and SiGe, on a bulk substrate is described. Fins for finFETs may be formed in an epitaxial layer of a first semiconductor type, and covered with an insulator. A portion of the fins may be removed to form voids in the insulator, and the voids may be filled by epitaxially growing a semiconductor material of a second type in the voids. The co-integrated finFETs may be formed at a same device level.
    Type: Application
    Filed: May 31, 2013
    Publication date: December 4, 2014
    Inventors: Nicolas Loubet, Prasanna Khare, Qing Liu
  • Publication number: 20140353717
    Abstract: An improved transistor with channel epitaxial silicon. In one aspect, a method of fabrication includes: forming a gate stack structure on an epitaxial silicon region disposed on a substrate, a width dimension of the epitaxial silicon region approximating a width dimension of the gate stack structure; and growing a raised epitaxial source and drain from the substrate, the raised epitaxial source and drain in contact with the epitaxial silicon region and the gate stack structure. For a SRAM device, further: removing an epitaxial layer in contact with the silicon substrate and the raised source and drain and to which the epitaxial silicon region is coupled leaving a space above the silicon substrate and under the raised epitaxial source and drain; and filling the space with an insulating layer and isolating the raised epitaxial source and drain and a channel of the transistor from the silicon substrate.
    Type: Application
    Filed: May 31, 2013
    Publication date: December 4, 2014
    Applicants: International Business Machines Corporation, STMicroelectronics, Inc.
    Inventors: Nicolas Loubet, Qing Liu, Prasanna Khare, Stephane Allegret-Maret, Bruce Doris, Kangguo Cheng
  • Publication number: 20140353718
    Abstract: An improved transistor with channel epitaxial silicon and methods for fabrication thereof. In one aspect, a method for fabricating a transistor includes: forming a gate stack structure on an epitaxial silicon region, a width dimension of the epitaxial silicon region approximating a width dimension of the gate stack structure; encapsulating the epitaxial silicon region under the gate stack structure with sacrificial spacers formed on both sides of the gate stack structure and the epitaxial silicon region; forming a channel of the transistor having a width dimension that approximates that of the epitaxial silicon region and the gate stack structure, the epitaxial silicon region and the gate stack structure formed on the channel of the transistor; removing the sacrificial spacers; and growing a raised epitaxial source and drain from the silicon substrate, with portions of the raised epitaxial source and drain in contact with the epitaxial silicon region.
    Type: Application
    Filed: May 31, 2013
    Publication date: December 4, 2014
    Applicants: International Business Machines Corporation, STMicroelectronics, Inc.
    Inventors: Nicolas Loubet, Qing Liu, Prasanna Khare, Stephane Allegret-Maret, Bruce Doris, Kangguo Cheng
  • Publication number: 20140353753
    Abstract: Improved fin field effect transistor (FinFET) devices and methods for fabrication thereof. In one aspect, a method for fabricating a FinFET device comprises: a silicon substrate on which a silicon epitaxial layer is grown is provided. Sacrificial structures on the substrate are formed from the epitaxial layer. A blanket silicon layer is formed over the sacrificial structures and exposed substrate portions, the blanket silicon layer having upper and lower portions of uniform thickness and intermediate portions interposed between the upper and lower portions of non-uniform thickness and having an angle of formation. An array of semiconducting fins is formed from the blanket silicon layer and a non-conformal layer formed over the blanket layer. The sacrificial structures are removed and the resulting void filled with isolation structures under the channel regions. Source and drain are formed in the source/drain regions during a fin merge of the FinFET.
    Type: Application
    Filed: May 31, 2013
    Publication date: December 4, 2014
    Applicants: International Business Machines Corporation, STMicroelectronics, Inc.
    Inventors: Nicolas Loubet, Shom Ponoth, Prasanna Khare, Qing Liu, Balasubramanian Pranatharthiharan
  • Publication number: 20140353767
    Abstract: On a first semiconductor material substrate, an overlying sacrificial layer formed of a second semiconductor material is deposited. In a first region, a first semiconductor material region is formed over the sacrificial layer. In a second region, a second semiconductor material region is formed over the sacrificial layer. The first semiconductor material region is patterned to define a first FinFET fin. The second semiconductor material region is patterned to define a second FinFET fin. The fins are each covered with a cap and sidewall spacer. The sacrificial layer formed of the second semiconductor material is then selectively removed to form an opening below each of the first and second FinFET fins (with those fins being supported by the sidewall spacers). The openings below each of the fins are then filled with a dielectric material that serves to isolate the semiconductive materials of the fins from the substrate.
    Type: Application
    Filed: May 31, 2013
    Publication date: December 4, 2014
    Inventors: Qing Liu, Nicolas Loubet, Shom Ponoth, Prasanna Khare, Balasubramanian Pranatharthiharan
  • Publication number: 20140357036
    Abstract: A method of making a semiconductor device includes forming an intermediate structure including second semiconductor fin portions above a first semiconductor layer, and top first semiconductor fin portions extending from respective ones of the second semiconductor fin portions. The second semiconductor fin portions are selectively etchable with respect to the top first semiconductor fin portions. A dummy gate is on the intermediate structure. The second semiconductor fin portions are selectively etched to define bottom openings under respective ones of the top first semiconductor fin portions. The bottom openings are filled with a dielectric material.
    Type: Application
    Filed: May 31, 2013
    Publication date: December 4, 2014
    Applicants: INTERNATIONAL BUSINESS MACHINES CORPORATION, STMICROELECTRONICS, INC.
    Inventors: Nicolas Loubet, Prasanna Khare, Huiming Bu
  • Publication number: 20140353716
    Abstract: A method of making a semiconductor device includes forming a fin mask layer on a semiconductor layer, forming a dummy gate over the fin mask layer, and forming source and drain regions on opposite sides of the dummy gate. The dummy gate is removed and the underlying fin mask layer is used to define a plurality of fins in the semiconductor layer. A gate is formed over the plurality of fins.
    Type: Application
    Filed: May 31, 2013
    Publication date: December 4, 2014
    Inventors: NICOLAS LOUBET, PRASANNA KHARE
  • Patent number: 8860123
    Abstract: A memory device may include a semiconductor substrate, and a memory transistor in the semiconductor substrate. The memory transistor may include source and drain regions in the semiconductor substrate and a channel region therebetween, and a gate stack having a first dielectric layer over the channel region, a second dielectric layer over the first dielectric layer, a first diffusion barrier layer over the second dielectric layer, a first electrically conductive layer over the first diffusion barrier layer, a second diffusion barrier layer over the first electrically conductive layer, and a second electrically conductive layer over the second diffusion barrier layer. The first and second dielectric layers may include different dielectric materials, and the first diffusion barrier layer may be thinner than the second diffusion barrier layer.
    Type: Grant
    Filed: March 28, 2013
    Date of Patent: October 14, 2014
    Assignees: STMicroelectronics, Inc., International Business Machines Corporation
    Inventors: Prasanna Khare, Stephane Allegret-Maret, Nicolas Loubet, Qing Liu, Hemanth Jagannathan, Lisa Edge, Kangguo Cheng, Bruce Doris
  • Publication number: 20140299880
    Abstract: Insulating layers can be formed over a semiconductor device region and etched in a manner that substantially reduces or prevents the amount of etching of the underlying channel region. A first insulating layer can be formed over a gate region and a semiconductor device region. A second insulating layer can be formed over the first insulating layer. A third insulating layer can be formed over the second insulating layer. A portion of the third insulating layer can be etched using a first etching process. A portion of the first and second insulating layers beneath the etched portion of the third insulating layer can be etched using at least a second etching process different from the first etching process.
    Type: Application
    Filed: June 19, 2014
    Publication date: October 9, 2014
    Applicant: STMicroelectronics, Inc.
    Inventors: Nicolas Loubet, Qing Liu, Prasanna Khare
  • Publication number: 20140291750
    Abstract: A memory device may include a semiconductor substrate, and a memory transistor in the semiconductor substrate. The memory transistor may include source and drain regions in the semiconductor substrate and a channel region therebetween, and a gate stack having a first dielectric layer over the channel region, a second dielectric layer over the first dielectric layer, a first diffusion barrier layer over the second dielectric layer, a first electrically conductive layer over the first diffusion barrier layer, a second diffusion barrier layer over the first electrically conductive layer, and a second electrically conductive layer over the second diffusion barrier layer. The first and second dielectric layers may include different dielectric materials, and the first diffusion barrier layer may be thinner than the second diffusion barrier layer.
    Type: Application
    Filed: March 28, 2013
    Publication date: October 2, 2014
    Applicants: INTERNATIONAL BUSINESS MACHINES CORPORATION, STMICROELECTRONICS, INC.
    Inventors: Prasanna KHARE, Stephane Allegret-Maret, Nicolas Loubet, Qing Liu, Hemanth Jagannathan, Lisa Edge, Kangguo Cheng, Bruce Doris