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).
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Patent number: 9419111Abstract: A multi-fin FINFET device may include a substrate and a plurality of semiconductor fins extending upwardly from the substrate and being spaced apart along the substrate. Each semiconductor fin may have opposing first and second ends and a medial portion therebetween, and outermost fins of the plurality of semiconductor fins may comprise an epitaxial growth barrier on outside surfaces thereof. The FINFET may further include at least one gate overlying the medial portions of the semiconductor fins, a plurality of raised epitaxial semiconductor source regions between the semiconductor fins adjacent the first ends thereof, and a plurality of raised epitaxial semiconductor drain regions between the semiconductor fins adjacent the second ends thereof.Type: GrantFiled: June 24, 2015Date of Patent: August 16, 2016Assignee: STMICROELECTRONICS, INC.Inventors: Qing Liu, Prasanna Khare, Nicolas Loubet
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Publication number: 20160149038Abstract: The presence of a facet or a void in an epitaxially grown crystal indicates that crystal growth has been interrupted by defects or by certain material boundaries. Faceting can be suppressed during epitaxial growth of silicon compounds that form source and drain regions of strained silicon transistors. It has been observed that faceting can occur when epitaxial layers of certain silicon compounds are grown adjacent to an oxide boundary, but faceting does not occur when the epitaxial layer is grown adjacent to a silicon boundary or adjacent to a nitride boundary. Because epitaxial growth of silicon compounds is often necessary in the vicinity of isolation trenches that are filled with oxide, techniques for suppression of faceting in these areas are of particular interest. One such technique, presented herein, is to line the isolation trenches with SiN to provide a barrier between the oxide and the region in which epitaxial growth is intended.Type: ApplicationFiled: December 29, 2015Publication date: May 26, 2016Inventors: Nicolas Loubet, Prasanna Khare, Qing Liu
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Patent number: 9349730Abstract: 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: GrantFiled: July 18, 2013Date of Patent: May 24, 2016Assignees: GLOBALFOUNDRIES INC., STMICROELECTRONICS, INC.Inventors: Ajey Poovannummoottil Jacob, Kangguo Cheng, Bruce B. Doris, Nicolas Loubet, Prasanna Khare, Ramachandra Divakaruni
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Publication number: 20160111338Abstract: 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: ApplicationFiled: December 15, 2015Publication date: April 21, 2016Inventors: NICOLAS LOUBET, PRASANNA KHARE, QING LIU
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Publication number: 20160104772Abstract: 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: ApplicationFiled: December 21, 2015Publication date: April 14, 2016Inventors: Nicolas Loubet, Prasanna Khare
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Patent number: 9252052Abstract: A shallow trench is formed to extend into a handle substrate of a semiconductor-on-insulator (SOI) layer. A dielectric liner stack of a dielectric metal oxide layer and a silicon nitride layer is formed in the shallow trench, followed by deposition of a shallow trench isolation fill portion. The dielectric liner stack is removed from above a top surface of a top semiconductor portion, followed by removal of a silicon nitride pad layer and an upper vertical portion of the dielectric metal oxide layer. A divot laterally surrounding a stack of a top semiconductor portion and a buried insulator portion is filled with a silicon nitride portion. Gate structures and source/drain structures are subsequently formed. The silicon nitride portion or the dielectric metal oxide layer functions as a stopping layer during formation of source/drain contact via holes, thereby preventing electrical shorts between source/drain contact via structures and the handle substrate.Type: GrantFiled: December 4, 2013Date of Patent: February 2, 2016Assignees: INTERNATIONAL BUSINESS MACHINES CORPORATION, STMicroelectronics, Inc., COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVESInventors: Bruce B. Doris, Shom Ponoth, Prasanna Khare, Qing Liu, Nicolas Loubet, Maud Vinet
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Publication number: 20160013096Abstract: A shallow trench is formed to extend into a handle substrate of a semiconductor-on-insulator (SOI) layer. A dielectric liner stack of a dielectric metal oxide layer and a silicon nitride layer is formed in the shallow trench, followed by deposition of a shallow trench isolation fill portion. The dielectric liner stack is removed from above a top surface of a top semiconductor portion, followed by removal of a silicon nitride pad layer and an upper vertical portion of the dielectric metal oxide layer. A divot laterally surrounding a stack of a top semiconductor portion and a buried insulator portion is filled with a silicon nitride portion. Gate structures and source/drain structures are subsequently formed. The silicon nitride portion or the dielectric metal oxide layer functions as a stopping layer during formation of source/drain contact via holes, thereby preventing electrical shorts between source/drain contact via structures and the handle substrate.Type: ApplicationFiled: September 17, 2015Publication date: January 14, 2016Inventors: Bruce B. Doris, Shom Ponoth, Prasanna Khare, Qing Liu, Nicolas Loubet, Maud Vinet
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Publication number: 20150325487Abstract: 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: ApplicationFiled: July 17, 2015Publication date: November 12, 2015Applicants: STMicroelectronics, Inc., International Business Machines CorporationInventors: Nicolas Loubet, Prasanna Khare, Qing Liu, Balasubramanian Pranatharthiharan, Shom Ponoth
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Patent number: 9171757Abstract: A shallow trench is formed to extend into a handle substrate of a semiconductor-on-insulator (SOI) layer. A dielectric liner stack of a dielectric metal oxide layer and a silicon nitride layer is formed in the shallow trench, followed by deposition of a shallow trench isolation fill portion. The dielectric liner stack is removed from above a top surface of a top semiconductor portion, followed by removal of a silicon nitride pad layer and an upper vertical portion of the dielectric metal oxide layer. A divot laterally surrounding a stack of a top semiconductor portion and a buried insulator portion is filled with a silicon nitride portion. Gate structures and source/drain structures are subsequently formed. The silicon nitride portion or the dielectric metal oxide layer functions as a stopping layer during formation of source/drain contact via holes, thereby preventing electrical shorts between source/drain contact via structures and the handle substrate.Type: GrantFiled: December 4, 2013Date of Patent: October 27, 2015Assignees: International Business Machines Corporation, STMicroelectronics, Inc., COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVESInventors: Bruce B. Doris, Shom Ponoth, Prasanna Khare, Qing Liu, Nicolas Loubet, Maud Vinet
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Publication number: 20150303285Abstract: A multi-fin FINFET device may include a substrate and a plurality of semiconductor fins extending upwardly from the substrate and being spaced apart along the substrate. Each semiconductor fin may have opposing first and second ends and a medial portion therebetween, and outermost fins of the plurality of semiconductor fins may comprise an epitaxial growth barrier on outside surfaces thereof. The FINFET may further include at least one gate overlying the medial portions of the semiconductor fins, a plurality of raised epitaxial semiconductor source regions between the semiconductor fins adjacent the first ends thereof, and a plurality of raised epitaxial semiconductor drain regions between the semiconductor fins adjacent the second ends thereof.Type: ApplicationFiled: June 24, 2015Publication date: October 22, 2015Inventors: QING LIU, PRASANNA KHARE, NICOLAS LOUBET
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Patent number: 9166023Abstract: 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: GrantFiled: August 9, 2013Date of Patent: October 20, 2015Assignees: STMICROELECTRONICS, INC., GLOBALFOUNDRIES, INC.Inventors: Nicolas Loubet, Prasanna Khare, Jin Cho
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Patent number: 9123809Abstract: 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: GrantFiled: September 24, 2014Date of Patent: September 1, 2015Assignee: STMicroelectronics, Inc.Inventors: Nicolas Loubet, Prasanna Khare, Qing Liu
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Patent number: 9099570Abstract: On a substrate formed of a first semiconductor material, a first overlying layer formed of a second semiconductor material is deposited. A second overlying layer formed of a third semiconductor material is deposited over the first overlying layer. The first and second overlying layers are patterned to define fins, wherein each fin includes a first region formed of the third material over a second region formed of the second material. An oxide material fills the space between the fins. A thermal oxidation is then performed to convert the second region to a material insulating the first region formed of the third material from the substrate. As an optional step, the second region formed of the second material is horizontally thinned before the oxide material is deposited and the thermal oxidation is performed. Once the fins are formed and insulated from the substrate, conventional FinFET fabrication is performed.Type: GrantFiled: December 5, 2013Date of Patent: August 4, 2015Assignee: STMicroelectronics, Inc.Inventors: Nicolas Loubet, Prasanna Khare
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Patent number: 9093556Abstract: A multi-fin FINFET device may include a substrate and a plurality of semiconductor fins extending upwardly from the substrate and being spaced apart along the substrate. Each semiconductor fin may have opposing first and second ends and a medial portion therebetween, and outermost fins of the plurality of semiconductor fins may comprise an epitaxial growth barrier on outside surfaces thereof. The FINFET may further include at least one gate overlying the medial portions of the semiconductor fins, a plurality of raised epitaxial semiconductor source regions between the semiconductor fins adjacent the first ends thereof, and a plurality of raised epitaxial semiconductor drain regions between the semiconductor fins adjacent the second ends thereof.Type: GrantFiled: August 21, 2012Date of Patent: July 28, 2015Assignee: STMICROELECTRONICS, INC.Inventors: Qing Liu, Prasanna Khare, Nicolas Loubet
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Patent number: 9093496Abstract: 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: GrantFiled: July 18, 2013Date of Patent: July 28, 2015Assignees: GLOBALFOUNDRIES INC., INTERNATIONAL BUSINESS MACHINES CORPORATION, STMICROELECTRONICS, INC.Inventors: Ajey P. Jacob, Kangguo Cheng, Bruce B. Doris, Nicolas Loubet, Prasanna Khare, Ramachandra Divakaruni
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Patent number: 9082788Abstract: 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: GrantFiled: May 31, 2013Date of Patent: July 14, 2015Assignees: STMICROELECTRONICS, INC., INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Nicolas Loubet, Prasanna Khare, Huiming Bu
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Publication number: 20150162248Abstract: On a substrate formed of a first semiconductor material, a first overlying layer formed of a second semiconductor material is deposited. A second overlying layer formed of a third semiconductor material is deposited over the first overlying layer. The first and second overlying layers are patterned to define fins, wherein each fin includes a first region formed of the third material over a second region formed of the second material. An oxide material fills the space between the fins. A thermal oxidation is then performed to convert the second region to a material insulating the first region formed of the third material from the substrate. As an optional step, the second region formed of the second material is horizontally thinned before the oxide material is deposited and the thermal oxidation is performed. Once the fins are formed and insulated from the substrate, conventional FinFET fabrication is performed.Type: ApplicationFiled: December 5, 2013Publication date: June 11, 2015Applicant: STMicroelectronics, Inc.Inventors: Nicolas Loubet, Prasanna Khare
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Publication number: 20150108585Abstract: Channel-to-substrate leakage in a FinFET device can be prevented by inserting an insulating layer between the semiconducting channel and the substrate. Similarly, source/drain-to-substrate leakage in a FinFET device can be prevented by isolating the source/drain regions from the substrate by inserting an insulating layer between the source/drain regions and the substrate. The insulating layer isolates the conduction path from the substrate both physically and electrically, thus preventing current leakage. If an array of semiconducting fins is made up of a multi-layer stack, the bottom material can be removed thus yielding a fin array that is suspended above the silicon surface. A resulting gap underneath the remaining top fin material can then be filled in with oxide to better support the fins and to isolate the array of fins from the substrate. The resulting FinFET device is fully substrate-isolated in both the gate region and the source/drain regions.Type: ApplicationFiled: December 31, 2014Publication date: April 23, 2015Inventors: Nicolas LOUBET, Prasanna KHARE
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Patent number: 9012999Abstract: A semiconductor device includes a semiconductor substrate having a channel region therein, a gate structure above the channel region, and source and drain regions on opposite sides of the gate structure. A respective contact is on each of the source and drain regions. At least one of the source and drain regions has an inclined upper contact surface with the respective contact. The inclined upper contact surface has at least a 50% greater area than would a corresponding flat contact surface.Type: GrantFiled: August 21, 2012Date of Patent: April 21, 2015Assignee: STMicroelectronics, Inc.Inventors: Qing Liu, Prasanna Khare, Nicolas Loubet
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Patent number: 9006816Abstract: 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. The gate stack may include a first dielectric layer over the channel region, a first diffusion barrier layer over the first dielectric layer, a first electrically conductive layer over the first diffusion barrier layer, a second dielectric layer over the first electrically conductive layer, a second diffusion barrier layer over the second dielectric 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: GrantFiled: March 28, 2013Date of Patent: April 14, 2015Assignees: STMicroelectronics, Inc., International Business Machines CorporationInventors: Prasanna Khare, Stephane Allegret-Maret, Nicolas Loubet, Qing Liu, Hemanth Jagannathan, Lisa Edge, Kangguo Cheng, Bruce Doris