Patents by Inventor Rajesh Khamankar

Rajesh Khamankar 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: 8809141
    Abstract: A silicon nitrate layer (110) is formed over a transistor gate (40) and source and drain regions (70). The as-formed silicon nitride layer (110) comprises a first tensile stress and a high hydrogen concentration. The as-formed silicon nitride layer (110) is thermally annealed converting the first tensile stress into a second tensile stress that is larger than the first tensile stress. Following the thermal anneal, the hydrogen concentration in the silicon nitride layer (110) is greater than 12 atomic percent.
    Type: Grant
    Filed: February 1, 2007
    Date of Patent: August 19, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Haowen Bu, Rajesh Khamankar, Douglas T. Grider
  • Patent number: 8114784
    Abstract: Integrated circuits (ICs) commonly contain pre-metal dielectric (PMD) liners with compressive stress to increase electron and hole mobilities in MOS transistors. The increase is limited by the thickness of the PMD liner. The instant invention is a multi-layered PMD liner in an integrated circuit which has a higher stress than single layer PMD liners. Each layer in the inventive PMD liner is exposed to a nitrogen-containing plasma, and which has a compressive stress higher than 1300 MPa. The PMD liner of the instant invention is composed of 3 to 10 layers. The hydrogen content of the first layer may be increased to improve transistor properties such as flicker noise and Negative Bias Temperature Instability (NBTI). An IC containing the inventive PMD liner and a method for forming same are also claimed.
    Type: Grant
    Filed: October 14, 2010
    Date of Patent: February 14, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Haowen Bu, Che-Jen Hu, Rajesh Khamankar
  • Patent number: 8084312
    Abstract: A transistor is fabricated upon a semiconductor substrate, where the yield strength or elasticity of the substrate is enhanced or otherwise adapted. A strain inducing layer is formed over the transistor to apply a strain thereto to alter transistor operating characteristics, and more particularly to enhance the mobility of carriers within the transistor. Enhancing carrier mobility allows transistor dimensions to be reduced while also allowing the transistor to operate as desired. However, high strain and temperature associated with fabricating the transistor result in deleterious plastic deformation. The yield strength of the silicon substrate is therefore adapted by incorporating nitrogen into the substrate, and more particularly into source/drain extension regions and/or source/drain regions of the transistor. The nitrogen can be readily incorporated during transistor fabrication by adding it as part of source/drain extension region formation and/or source/drain region formation.
    Type: Grant
    Filed: January 15, 2010
    Date of Patent: December 27, 2011
    Assignee: Texas Instruments Incorporated
    Inventors: Srinivasan Chakravarthi, P R Chidambaram, Rajesh Khamankar, Haowen Bu, Douglas T. Grider
  • Patent number: 8084787
    Abstract: Semiconductor devices (102) and fabrication methods (10) are provided, in which a nitride film (130) is formed over NMOS transistors to impart a tensile stress in ail or a portion of the NMOS transistor to improve carrier mobility. The nitride layer (130) is initially deposited over the transistors at low temperature with high hydrogen content to provide a moderate tensile stress in the semiconductor body prior to back-end processing. Subsequent back-end thermal processing reduces the film hydrogen content and causes an increase in the applied tensile stress.
    Type: Grant
    Filed: April 26, 2007
    Date of Patent: December 27, 2011
    Assignee: Texas Instruments Incorporated
    Inventors: Haowen Bu, Rajesh Khamankar, Douglas T. Grider
  • Patent number: 8021990
    Abstract: A MOSFET structure including silicate gate dielectrics with nitridation treatments of the gate dielectric prior to gate material deposition.
    Type: Grant
    Filed: April 9, 2009
    Date of Patent: September 20, 2011
    Assignee: Texas Instruments Incorporated
    Inventors: Antonio L. P. Rotondaro, Luigi Colombo, Mark R Visokay, Rajesh Khamankar, Douglas E Mercer
  • Publication number: 20110027953
    Abstract: Integrated circuits (ICs) commonly contain pre-metal dielectric (PMD) liners with compressive stress to increase electron and hole mobilities in MOS transistors. The increase is limited by the thickness of the PMD liner. The instant invention is a multi-layered PMD liner in an integrated circuit which has a higher stress than single layer PMD liners. Each layer in the inventive PMD liner is exposed to a nitrogen-containing plasma, and which has a compressive stress higher than 1300 MPa. The PMD liner of the instant invention is composed of 3 to 10 layers. The hydrogen content of the first layer may be increased to improve transistor properties such as flicker noise and Negative Bias Temperature Instability (NBTI). An IC containing the inventive PMD liner and a method for forming same are also claimed.
    Type: Application
    Filed: October 14, 2010
    Publication date: February 3, 2011
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Haowen Bu, Jerry Che-Jen Hu, Rajesh Khamankar
  • Patent number: 7847401
    Abstract: A method (100) of forming semiconductor structures (202) including high-temperature processing steps (step 118), incorporates the use of a high-temperature nitride-oxide mask (220) over protected regions (214) of the device (202). The invention has application in many different embodiments, including but not limited to, the formation of recess, strained device regions (224).
    Type: Grant
    Filed: May 7, 2009
    Date of Patent: December 7, 2010
    Assignee: Texas Instruments Incorporated
    Inventors: P R Chidambaram, Haowen Bu, Rajesh Khamankar, Douglas T Grider
  • Publication number: 20100120215
    Abstract: A transistor is fabricated upon a semiconductor substrate, where the yield strength or elasticity of the substrate is enhanced or otherwise adapted. A strain inducing layer is formed over the transistor to apply a strain thereto to alter transistor operating characteristics, and more particularly to enhance the mobility of carriers within the transistor. Enhancing carrier mobility allows transistor dimensions to be reduced while also allowing the transistor to operate as desired. However, high strain and temperature associated with fabricating the transistor result in deleterious plastic deformation. The yield strength of the silicon substrate is therefore adapted by incorporating nitrogen into the substrate, and more particularly into source/drain extension regions and/or source/drain regions of the transistor. The nitrogen can be readily incorporated during transistor fabrication by adding it as part of source/drain extension region formation and/or source/drain region formation.
    Type: Application
    Filed: January 15, 2010
    Publication date: May 13, 2010
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Srinivasan CHAKRAVARTHI, PR CHIDAMBARAM, Rajesh KHAMANKAR, Haowen BU, Douglas T. GRIDER
  • Patent number: 7682988
    Abstract: A method of reducing threshold voltage shift of a MOSFET transistor resulting after temperature and voltage stress, and an integrated circuit device fabricated according to the method. The method includes the steps of forming a nitrided dielectric layer on a semiconductor substrate, and subjecting the nitrided dielectric layer to an anneal at low pressure.
    Type: Grant
    Filed: August 31, 2004
    Date of Patent: March 23, 2010
    Assignee: Texas Instruments Incorporated
    Inventors: Husam N. Alshareef, Rajesh Khamankar, Ajith Varghese, Cathy A. Chancellor, Anand Krishnan, Malcolm J. Bevan
  • Patent number: 7670892
    Abstract: A transistor is fabricated upon a semiconductor substrate, where the yield strength or elasticity of the substrate is enhanced or otherwise adapted. A strain inducing layer is formed over the transistor to apply a strain thereto to alter transistor operating characteristics, and more particularly to enhance the mobility of carriers within the transistor. Enhancing carrier mobility allows transistor dimensions to be reduced while also allowing the transistor to operate as desired. However, high strain and temperature associated with fabricating the transistor result in deleterious plastic deformation. The yield strength of the silicon substrate is therefore adapted by incorporating nitrogen into the substrate, and more particularly into source/drain extension regions and/or source/drain regions of the transistor. The nitrogen can be readily incorporated during transistor fabrication by adding it as part of source/drain extension region formation and/or source/drain region formation.
    Type: Grant
    Filed: November 7, 2005
    Date of Patent: March 2, 2010
    Assignee: Texas Instruments Incorporated
    Inventors: Srinivasan Chakravarthi, Pr Chidambaram, Rajesh Khamankar, Haowen Bu, Douglas T. Grider
  • Patent number: 7601575
    Abstract: The present invention facilitates semiconductor device operation and fabrication by providing a cap-annealing process that improves channel electron mobility without substantially degrading PMOS transistor devices. The process uses an oxide/nitride composite cap to alter the active dopant profile across the channel regions. During an annealing process, dopants migrate out of the Si/SiO2 in a channel region thereby altering the dopant profile of the channel region. This altered profile generally improves channel mobility thereby improving transistor performance and permitting smaller density designs.
    Type: Grant
    Filed: March 4, 2005
    Date of Patent: October 13, 2009
    Assignee: Texas Instruments Incorporated
    Inventors: Haowen Bu, Shashank Ekbote, Rajesh Khamankar, Shaoping Tang, Freidoon Mehrad
  • Publication number: 20090227117
    Abstract: A MOSFET structure including silicate gate dielectrics with nitridation treatments of the gate dielectric prior to gate material deposition.
    Type: Application
    Filed: April 9, 2009
    Publication date: September 10, 2009
    Applicant: Texas Instruments Incorporated
    Inventors: Antonio L.P. Rotondaro, Luigi Colombo, Mark R. Visokay, Rajesh Khamankar, Douglas E. Mercer
  • Publication number: 20090224296
    Abstract: A method (100) of forming semiconductor structures (202) including high-temperature processing steps (step 118), incorporates the use of a high-temperature nitride-oxide mask (220) over protected regions (214) of the device (202). The invention has application in many different embodiments, including but not limited to, the formation of recess, strained device regions (224).
    Type: Application
    Filed: May 7, 2009
    Publication date: September 10, 2009
    Applicant: Texas Instruments Incorporated
    Inventors: PR Chidambaram, Haowen Bu, Rajesh Khamankar, Douglas T. Grider
  • Patent number: 7560792
    Abstract: Dual gate dielectric layers are formed on a semiconductor substrate for MOS transistor fabrication. A first dielectric layer (30) is formed on a semiconductor substrate (10). A first plasma nitridation process is performed on said first dielectric layer. The first dielectric layer (30) is removed in regions of the substrate and a second dielectric layer (50) is formed in these regions. A second plasma nitridation process is performed on the first dielectric layer and the second dielectric layer. MOS transistors (160, 170) are then fabricated using the dielectric layers (30, 50).
    Type: Grant
    Filed: January 24, 2007
    Date of Patent: July 14, 2009
    Assignee: Texas Instruments Incorporated
    Inventors: Rajesh Khamankar, Douglas T. Grider, Hiroaki Niimi, April Gurba, Toan Tran, James J. Chambers
  • Patent number: 7553718
    Abstract: A method (100) of forming semiconductor structures (202) including high-temperature processing steps (step 118), incorporates the use of a high-temperature nitride-oxide mask (220) over protected regions (214) of the device (202). The invention has application in many different embodiments, including but not limited to, the formation of recess, strained device regions (224).
    Type: Grant
    Filed: January 28, 2005
    Date of Patent: June 30, 2009
    Assignee: Texas Instruments Incorporated
    Inventors: Periannan Chidambaram, Haowen Bu, Rajesh Khamankar, Douglas T. Grider
  • Publication number: 20090152639
    Abstract: Integrated circuits (ICs) commonly contain pre-metal dielectric (PMD) liners with compressive stress to increase electron and hole mobilities in MOS transistors. The increase is limited by the thickness of the PMD liner. The instant invention is a multi-layered PMD liner in an integrated circuit which has a higher stress than single layer PMD liners. Each layer in the inventive PMD liner is exposed to a nitrogen-containing plasma, and which has a compressive stress higher than 1300 MPa. The PMD liner of the instant invention is composed of 3 to 10 layers. The hydrogen content of the first layer may be increased to improve transistor properties such as flicker noise and Negative Bias Temperature Instabilty (NBTI). An IC containing the inventive PMD liner and a method for forming same are also claimed.
    Type: Application
    Filed: December 18, 2007
    Publication date: June 18, 2009
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Haowen Bu, Jerry Che-Jen Hu, Rajesh Khamankar
  • Patent number: 7535066
    Abstract: A MOSFET structure including silicate gate dielectrics with nitridation treatments of the gate dielectric prior to gate material deposition.
    Type: Grant
    Filed: January 23, 2003
    Date of Patent: May 19, 2009
    Assignee: Texas Instruments Incorporated
    Inventors: Antonio L. P. Rotondaro, Luigi Colombo, Mark R. Visokay, Rajesh Khamankar, Douglas E. Mercer
  • Patent number: 7514308
    Abstract: The present invention provides a complementary metal oxide semiconductor (CMOS) device, a method of manufacture therefor, and an integrated circuit including the same. The CMOS device (100), in an exemplary embodiment of the present invention, includes a p-channel metal oxide semiconductor (PMOS) device (120) having a first gate dielectric layer (133) and a first gate electrode layer (138) located over a substrate (110), wherein the first gate dielectric layer (133) has an amount of nitrogen located therein. In addition to the PMOS device (120), the CMOS device further includes an n-channel metal oxide semiconductor (NMOS) device (160) having a second gate dielectric layer (173) and a second gate electrode layer (178) located over the substrate (110), wherein the second gate dielectric layer (173) has a different amount of nitrogen located therein. Accordingly, the present invention allows for the individual tuning of the threshold voltages for the PMOS device (120) and the NMOS device (160).
    Type: Grant
    Filed: May 8, 2007
    Date of Patent: April 7, 2009
    Assignee: Texas Instruments Incorporated
    Inventors: Ajith Varghese, Husam N. Alshareef, Rajesh Khamankar
  • Publication number: 20090045472
    Abstract: A semiconductor device includes source/drain regions formed in a substrate and having a concentration of nitrogen of at least about 5E18 cm?3. A gate dielectric is located over the substrate and between the source/drain regions. Gate sidewall spacers are located over said source/drain regions. A nitrogen-doped electrode including polysilicon is located over the gate dielectric. The electrode has a concentration of nitrogen therein greater than the concentration of nitrogen in the source/drain regions.
    Type: Application
    Filed: August 13, 2007
    Publication date: February 19, 2009
    Applicant: Texas Instruments Incorporated
    Inventors: Srinivasan Chakravarthi, Narendra Singh Mehta, Rajesh Khamankar, Ajith Varghese, Malcolm J. Bevan, Tad Grider
  • Publication number: 20080251850
    Abstract: Semiconductor devices (102) and fabrication methods (10) are provided, in which a nitride film (130) is formed over NMOS transistors to impart a tensile stress in ail or a portion of the NMOS transistor to improve carrier mobility. The nitride layer (130) is initially deposited over the transistors at low temperature with high hydrogen content to provide a moderate tensile stress in the semiconductor body prior to back-end processing. Subsequent back-end thermal processing reduces the film hydrogen content and causes an increase in the applied tensile stress.
    Type: Application
    Filed: April 26, 2007
    Publication date: October 16, 2008
    Applicant: Texas Instruments Incorporated
    Inventors: Haowen Bu, Rajesh Khamankar, Douglas T. Grider