Patents by Inventor Rohit Pal

Rohit Pal 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: 20120208337
    Abstract: A low energy surface is formed by a high temperature anneal of the surfaces of trenches on each side of a gate stack. The material of the semiconductor layer reflows during the high temperature anneal such that the low energy surface is a crystallographic surface that is at a non-orthogonal angle with the surface normal of the semiconductor layer. A lattice mismatched semiconductor material is selectively grown on the semiconductor layer to fill the trenches, thereby forming embedded lattice mismatched semiconductor material portions in source and drain regions of a transistor. The embedded lattice mismatched semiconductor material portions can be in-situ doped without increasing punch-through. Alternately, a combination of intrinsic selective epitaxy and ion implantation can be employed to form deep source and drain regions.
    Type: Application
    Filed: April 26, 2012
    Publication date: August 16, 2012
    Applicants: GLOBALFOUNDRIES INC., INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Brian J. Greene, William K. Henson, Judson R. Holt, Michael D. Steigerwalt, Kuldeep Amarnath, Rohit Pal, Johan W. Weijtmans
  • Publication number: 20120193727
    Abstract: Sophisticated gate electrode structures may be formed by providing a cap layer including a desired species that may diffuse into the gate dielectric material prior to performing a treatment for stabilizing the sensitive gate dielectric material. In this manner, complex high-k metal gate electrode structures may be formed on the basis of reduced temperatures and doses for a threshold adjusting species compared to conventional strategies. Moreover, a single metal-containing electrode material may be deposited for both types of transistors.
    Type: Application
    Filed: April 12, 2012
    Publication date: August 2, 2012
    Inventors: Richard Carter, Martin Trentzsch, Sven Beyer, Rohit Pal
  • Patent number: 8222673
    Abstract: A low energy surface is formed by a high temperature anneal of the surfaces of trenches on each side of a gate stack. The material of the semiconductor layer reflows during the high temperature anneal such that the low energy surface is a crystallographic surface that is at a non-orthogonal angle with the surface normal of the semiconductor layer. A lattice mismatched semiconductor material is selectively grown on the semiconductor layer to fill the trenches, thereby forming embedded lattice mismatched semiconductor material portions in source and drain regions of a transistor. The embedded lattice mismatched semiconductor material portions can be in-situ doped without increasing punch-through. Alternately, a combination of intrinsic selective epitaxy and ion implantation can be employed to form deep source and drain regions.
    Type: Grant
    Filed: June 8, 2010
    Date of Patent: July 17, 2012
    Assignees: International Business Machines Corporation, Globalfoundries Inc.
    Inventors: Brian J. Greene, William K. Henson, Judson R. Holt, Michael D. Steigerwalt, Kuldeep Amarnath, Rohit Pal, Johan W. Weijtmans
  • Patent number: 8217463
    Abstract: Methods for protecting gate stacks during fabrication of semiconductor devices and semiconductor devices fabricated from such methods are provided. Methods for fabricating a semiconductor device include providing a semiconductor substrate having an active region and a shallow trench isolation (STI) region. Epitaxial layer is formed on the active region to define a lateral overhang portion in a divot at the active region/STI region interface. A gate stack is formed having a first gate stack-forming layer overlying the semiconductor substrate. First gate stack-forming layer includes a non-conformal layer of metal gate-forming material which is directionally deposited to form a thinned break portion just below the lateral overhang portion. After the step of forming the gate stack, a first portion of the non-conformal layer is in the gate stack and a second portion is exposed. The thinned break portion at least partially isolates the first and second portions during subsequent etch chemistries.
    Type: Grant
    Filed: February 4, 2011
    Date of Patent: July 10, 2012
    Assignee: GLOBALFOUNDRIES Inc.
    Inventors: Rohit Pal, Michael Hargrove, Frank Bin Yang
  • Publication number: 20120156864
    Abstract: When forming sophisticated high-k metal gate electrode structures, the uniformity of the device characteristics may be enhanced by growing a threshold adjusting semiconductor alloy on the basis of a hard mask regime, which may result in a less pronounced surface topography, in particular in densely packed device areas. To this end, in some illustrative embodiments, a deposited hard mask material may be used for selectively providing an oxide mask of reduced thickness and superior uniformity.
    Type: Application
    Filed: August 3, 2011
    Publication date: June 21, 2012
    Applicant: GLOBALFOUNDRIES INC.
    Inventors: Stephan Kronholz, Rohit Pal
  • Patent number: 8198192
    Abstract: Sophisticated gate electrode structures may be formed by providing a cap layer including a desired species that may diffuse into the gate dielectric material prior to performing a treatment for stabilizing the sensitive gate dielectric material. In this manner, complex high-k metal gate electrode structures may be formed on the basis of reduced temperatures and doses for a threshold adjusting species compared to conventional strategies. Moreover, a single metal-containing electrode material may be deposited for both types of transistors.
    Type: Grant
    Filed: May 7, 2010
    Date of Patent: June 12, 2012
    Assignee: GlobalFoundries Inc.
    Inventors: Richard Carter, Martin Trentzsch, Sven Beyer, Rohit Pal
  • Publication number: 20120129311
    Abstract: Semiconductor transistor devices and related fabrication methods are provided. An exemplary transistor device includes a layer of semiconductor material having a channel region defined therein and a gate structure overlying the channel region. Recesses are formed in the layer of semiconductor material adjacent to the channel region, such that the recesses extend asymmetrically toward the channel region. The transistor device also includes stress-inducing semiconductor material formed in the recesses. The asymmetric profile of the stress-inducing semiconductor material enhances carrier mobility in a manner that does not exacerbate the short channel effect.
    Type: Application
    Filed: January 20, 2012
    Publication date: May 24, 2012
    Applicant: GLOBALFOUNDRIES Inc.
    Inventors: Rohit PAL, Frank Bin YANG, Michael J. HARGROVE
  • Publication number: 20120119308
    Abstract: Improved semiconductor devices including metal gate electrodes are formed with reduced performance variability by reducing the initial high dopant concentration at the top portion of the silicon layer overlying the metal layer. Embodiments include reducing the dopant concentration in the upper portion of the silicon layer, by implanting a counter-dopant into the upper portion of the silicon layer, removing the high dopant concentration portion and replacing it with undoped or lightly doped silicon, and applying a gettering agent to the upper surface of the silicon layer to form a thin layer with the gettered dopant, which layer can be removed or retained.
    Type: Application
    Filed: January 18, 2012
    Publication date: May 17, 2012
    Applicant: GLOBALFOUNDRIES Inc.
    Inventors: Man Fai NG, Rohit Pal
  • Publication number: 20120112281
    Abstract: Semiconductor devices with high-K/metal gates are formed with spacers that are substantially resistant to subsequent etching to remove an overlying spacer, thereby avoiding replacement and increasing manufacturing throughput. Embodiments include forming a high-K/metal gate, having an upper surface and side surfaces, over a substrate, e.g., a SOI substrate, and sequentially forming, on the side surfaces of the high-K/metal gate, a first spacer of a non-oxide material, a second spacer, of a material different from that of the first spacer, and a third spacer, of a material different from that of the second spacer. After formation of source and drain regions, e.g., epitaxially grown silicon-germanium, the third spacer is etched with an etchant, such as hot phosphoric acid, to which the second spacer is substantially resistant, thereby avoiding replacement.
    Type: Application
    Filed: January 13, 2012
    Publication date: May 10, 2012
    Applicant: GLOBALFOUNDRIES Inc.
    Inventors: Rohit PAL, Stephan Waidmann
  • Patent number: 8148750
    Abstract: Semiconductor transistor devices and related fabrication methods are provided. An exemplary transistor device includes a layer of semiconductor material having a channel region defined therein and a gate structure overlying the channel region. Recesses are formed in the layer of semiconductor material adjacent to the channel region, such that the recesses extend asymmetrically toward the channel region. The transistor device also includes stress-inducing semiconductor material formed in the recesses. The asymmetric profile of the stress-inducing semiconductor material enhances carrier mobility in a manner that does not exacerbate the short channel effect.
    Type: Grant
    Filed: March 21, 2011
    Date of Patent: April 3, 2012
    Assignee: GLOBALFOUNDRIES Inc.
    Inventors: Rohit Pal, Frank Bin Yang, Michael J. Hargrove
  • Patent number: 8124515
    Abstract: Improved semiconductor devices comprising metal gate electrodes are formed with reduced performance variability by reducing the initial high dopant concentration at the top portion of the silicon layer overlying the metal layer. Embodiments include reducing the dopant concentration in the upper portion of the silicon layer, by implanting a counter-dopant into the upper portion of the silicon layer, removing the high dopant concentration portion and replacing it with undoped or lightly doped silicon, and applying a gettering agent to the upper surface of the silicon layer to form a thin layer with the gettered dopant, which layer can be removed or retained.
    Type: Grant
    Filed: May 20, 2009
    Date of Patent: February 28, 2012
    Assignee: GLOBALFOUNDRIES Inc.
    Inventors: Man Fai Ng, Rohit Pal
  • Patent number: 8119464
    Abstract: Semiconductor devices with high-K/metal gates are formed with spacers that are substantially resistant to subsequent etching to remove an overlying spacer, thereby avoiding replacement and increasing manufacturing throughput. Embodiments include forming a high-K/metal gate, having an upper surface and side surfaces, over a substrate, e.g., a SOI substrate, and sequentially forming, on the side surfaces of the high-K/metal gate, a first spacer of a non-oxide material, a second spacer, of a material different from that of the first spacer, and a third spacer, of a material different from that of the second spacer. After formation of source and drain regions, e.g., epitaxially grown silicon-germanium, the third spacer is etched with an etchant, such as hot phosphoric acid, to which the second spacer is substantially resistant, thereby avoiding replacement.
    Type: Grant
    Filed: September 17, 2009
    Date of Patent: February 21, 2012
    Assignee: GLOBALFOUNDRIES Inc.
    Inventors: Rohit Pal, Stephan Waidmann
  • Patent number: 8084828
    Abstract: Methods for protecting gate stacks during fabrication of semiconductor devices and semiconductor devices fabricated from such methods are provided. In an embodiment, a method for fabricating a semiconductor device comprises forming a gate stack comprising a first gate stack-forming layer overlying a semiconductor substrate and forming first sidewall spacers about sidewalls of the gate stack. After the step of forming the first sidewall spacers, a portion of the first gate stack-forming layer is exposed. The exposed portion is anisotropically etched using the gate stack and the first sidewall spacers as an etch mask. Second sidewall spacers are formed adjacent the first sidewall spacers after the step of anisotropically etching.
    Type: Grant
    Filed: June 14, 2010
    Date of Patent: December 27, 2011
    Assignee: GLOBALFOUNDRIES Inc.
    Inventors: Rohit Pal, Man Fai Ng, David Brown
  • Patent number: 8076209
    Abstract: Methods for forming a semiconductor device comprising a silicon-comprising substrate are provided. One exemplary method comprises depositing a polysilicon layer overlying the silicon-comprising substrate, amorphizing the polysilicon layer, etching the amorphized polysilicon layer to form a gate electrode, etching recesses into the substrate using the gate electrode as an etch mask, depositing a stress-inducing layer overlying the gate electrode, annealing the silicon-comprising substrate to recrystallize the gate electrode, removing the stress-inducing layer, and epitaxially growing impurity-doped, silicon-comprising regions in the recesses.
    Type: Grant
    Filed: April 30, 2010
    Date of Patent: December 13, 2011
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Frank Bin Yang, Rohit Pal, Michael J. Hargrove
  • Publication number: 20110298008
    Abstract: A low energy surface is formed by a high temperature anneal of the surfaces of trenches on each side of a gate stack. The material of the semiconductor layer reflows during the high temperature anneal such that the low energy surface is a crystallographic surface that is at a non-orthogonal angle with the surface normal of the semiconductor layer. A lattice mismatched semiconductor material is selectively grown on the semiconductor layer to fill the trenches, thereby forming embedded lattice mismatched semiconductor material portions in source and drain regions of a transistor. The embedded lattice mismatched semiconductor material portions can be in-situ doped without increasing punch-through. Alternately, a combination of intrinsic selective epitaxy and ion implantation can be employed to form deep source and drain regions.
    Type: Application
    Filed: June 8, 2010
    Publication date: December 8, 2011
    Applicants: GLOBALFOUNDRIES INC., INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Brian J. Greene, William K. Henson, Judson R. Holt, Michael D. Steigerwalt, Kuldeep Amarnath, Rohit Pal, Johan W. Weijtmans
  • Patent number: 8026539
    Abstract: Methods are provided for forming a semiconductor device comprising a semiconductor substrate. In accordance with an exemplary embodiment, a method comprises the steps of forming a high-k dielectric layer overlying the semiconductor substrate, forming a metal-comprising gate layer overlying the high-k dielectric layer, forming a doped silicon-comprising capping layer overlying the metal-comprising gate layer, and depositing a silicon-comprising gate layer overlying the doped silicon-comprising capping layer.
    Type: Grant
    Filed: February 18, 2009
    Date of Patent: September 27, 2011
    Assignee: GLOBALFOUNDRIES Inc.
    Inventors: Michael Hargrove, Frank Bin Yang, Rohit Pal
  • Publication number: 20110204446
    Abstract: A metal oxide semiconductor transistor device having a reduced gate height is provided. One embodiment of the device includes a substrate having a layer of semiconductor material, a gate structure overlying the layer of semiconductor material, and source/drain recesses formed in the semiconductor material adjacent to the gate structure, such that remaining semiconductor material is located below the source/drain recesses. The device also includes shallow source/drain implant regions formed in the remaining semiconductor material, and epitaxially grown, in situ doped, semiconductor material in the source/drain recesses.
    Type: Application
    Filed: April 29, 2011
    Publication date: August 25, 2011
    Applicant: GLOBALFOUNDRIES INC.
    Inventors: Frank Bin YANG, Rohit PAL, Scott LUNING
  • Patent number: 7994014
    Abstract: The disclosed subject matter relates to semiconductor transistor devices and associated fabrication techniques that can be utilized to form silicide contacts having an increased effective size, relative to conventional silicide contacts. A semiconductor device fabricated in accordance with the processes disclosed herein includes a layer of semiconductor material and a gate structure overlying the layer of semiconductor material. A channel region is formed in the layer of semiconductor material, the channel region underlying the gate structure. The semiconductor device also includes source and drain regions in the layer of semiconductor material, wherein the channel region is located between the source and drain regions. Moreover, the semiconductor device includes facet-shaped silicide contact areas overlying the source and drain regions.
    Type: Grant
    Filed: October 10, 2008
    Date of Patent: August 9, 2011
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Frank Bin Yang, Rohit Pal, Michael J. Hargrove
  • Publication number: 20110169083
    Abstract: A method of fabricating a semiconductor device with back side conductive plugs is provided here. The method begins by forming a gate structure overlying a semiconductor-on-insulator (SOI) substrate. The SOI substrate has a support layer, an insulating layer overlying the support layer, an active semiconductor region overlying the insulating layer, and an isolation region outboard of the active semiconductor region. A first section of the gate structure is formed overlying the isolation region and a second section of the gate structure is formed overlying the active semiconductor region. The method continues by forming source/drain regions in the active semiconductor region, and thereafter removing the support layer from the SOI substrate. Next, the method forms conductive plugs for the gate structure and the source/drain regions, where each of the conductive plugs passes through the insulating layer.
    Type: Application
    Filed: January 14, 2010
    Publication date: July 14, 2011
    Applicant: GLOBALFOUNDRIES INC.
    Inventors: Bin YANG, Rohit PAL, Michael HARGROVE
  • Publication number: 20110169073
    Abstract: Semiconductor transistor devices and related fabrication methods are provided. An exemplary transistor device includes a layer of semiconductor material having a channel region defined therein and a gate structure overlying the channel region. Recesses are formed in the layer of semiconductor material adjacent to the channel region, such that the recesses extend asymmetrically toward the channel region. The transistor device also includes stress-inducing semiconductor material formed in the recesses. The asymmetric profile of the stress-inducing semiconductor material enhances carrier mobility in a manner that does not exacerbate the short channel effect.
    Type: Application
    Filed: March 21, 2011
    Publication date: July 14, 2011
    Applicant: GLOBALFOUNDRIES INC.
    Inventors: Rohit PAL, Frank Bin YANG, Michael J. HARGROVE