Patents by Inventor Ajith Varghese

Ajith Varghese 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: 20080246099
    Abstract: An integrated circuit device is disclosed as comprising a feature that is susceptible to oxidation. A poly-oxide coating is used over the feature susceptible to oxidation to protect the feature susceptible to oxidation from oxidizing. Various method can be used to form the poly-oxide coating include conversion of a ploy-silicon coating using UV O3 low temperature oxidation and plasma nitridation using either decoupled plasma nitridation or NH3 annealing.
    Type: Application
    Filed: April 9, 2007
    Publication date: October 9, 2008
    Inventors: Ajith Varghese, James J. Chambers
  • Publication number: 20080230815
    Abstract: Sidewall spacers that are primarily oxide, instead of nitride, are formed adjacent to a gate stack of a CMOS transistor. Individual sidewall spacers are situated between a conductive gate electrode of the gate stack and a conductive contact of the transistor. As such, a capacitance can develop between the gate electrode and the contact, depending on the dielectric constant of the interposed sidewall spacer. Accordingly, forming sidewall spacers out of oxide, which has a lower dielectric constant than nitride, mitigates capacitance that can otherwise develop between these features. Such capacitance is undesirable, at least, because it can inhibit transistor switching speeds. Accordingly, fashioning sidewall spacers as described herein can mitigate yield loss by reducing the number of devices that have unsatisfactory switching speeds and/or other undesirable performance characteristics.
    Type: Application
    Filed: March 21, 2007
    Publication date: September 25, 2008
    Inventors: Shashank Sureshchandra Ekbote, Borna Obradovic, Lindsey Hall, Craig Huffman, Ajith Varghese
  • Publication number: 20080217703
    Abstract: A method for manufacturing an isolation structure is disclosed that protects the isolation structure during etching of a dichlorosilane (DCS) nitride layer. The method involves the formation of a bis-(t-butylamino)silane-based nitride liner layer within the isolation trench, which exhibits a five-fold greater resistance to nitride etching solutions as compared with DCS nitride, thereby allowing protection against damage from unintended over-etching. The bis-(t-butylamino)silane-based nitride layer also exerts a greater tensile strain on moat regions that results in heightened carrier mobility of active regions, thereby increasing the performance of NMOS transistors embedded therein.
    Type: Application
    Filed: December 27, 2007
    Publication date: September 11, 2008
    Inventors: Narendra Singh Mehta, Wayne Anthony Bather, Ajith Varghese
  • Patent number: 7396728
    Abstract: A method forms a semiconductor device comprising isolation structures that selectively induce strain into active regions of NMOS and PMOS devices. Form a hard mask layer over a semiconductor body. A resist layer is formed on the hard mask layer that exposes and defines isolation regions. The hard mask layer is patterned and trench regions are formed using the hard mask layer as a mask. An oxide trench liner that induces compressive strain into active regions of the PMOS region is formed within trench regions of the PMOS region. A nitride trench liner that induces tensile strain into active regions of the NMOS region is formed within the NMOS trench regions.
    Type: Grant
    Filed: June 29, 2005
    Date of Patent: July 8, 2008
    Assignee: Texas Instruments Incorporated
    Inventors: Ajith Varghese, Narendra Singh Mehta, Jonathan McAulay Holt
  • Patent number: 7384861
    Abstract: A method forms a semiconductor device comprising a modifiable strain inducing layer. A semiconductor body is provided. First and second regions of the semiconductor body are identified. A modifiable tensile strain inducing layer is formed over the device within the first and second regions. A mask is then formed that exposes the second region and covers the first region. A material is selected for a modification implant and the selected material is implanted into the second region thereby converting a portion of the modifiable tensile strain inducing layer into a compressive strain inducing layer within the PMOS region.
    Type: Grant
    Filed: July 18, 2005
    Date of Patent: June 10, 2008
    Assignee: Texas Instruments Incorporated
    Inventors: Narendra Singh Mehta, Wayne Anthony Bather, Ajith Varghese
  • Publication number: 20080076076
    Abstract: In one embodiment, a method of manufacturing an integrated circuit that comprises forming a circuit layer over a substrate, forming a resist layer on the circuit layer, and subjecting the resist layer to a rework process that includes exposing the resist layer to an organic wash. In another embodiment, the method of manufacturing an integrated circuit comprises forming a circuit layer over a substrate, forming a priming layer on the circuit layer, and subjecting the resist layer to the rework process. The reworking process includes exposing the substrate to a mild plasma ash to substantially remove portions of the resist layer but leave the priming layer.
    Type: Application
    Filed: September 22, 2006
    Publication date: March 27, 2008
    Applicant: Texas Instruments Incorporated
    Inventors: Yaw Samuel Obeng, Yu-Tai Lee, Rajesh Khamankar, April Gurba, Brian Kirkpatrick, Ajith Varghese
  • Publication number: 20080006886
    Abstract: A method of manufacturing a semiconductor device including calibrating an ion implant process. The calibration includes forming a dielectric layer over a calibration substrate. A dopant is implanted into the dielectric layer. Charge is deposited on a surface of the dielectric layer, and voltage on the surface is measured. An electrical characteristic of the dielectric layer is determined, and a doping level of the dielectric layer is determined from the electrical characteristic. The electrical characteristic is associated with an operating set-point of the ion implant process. The calibrated ion implant process is used to implant the dopant into a semiconductor substrate.
    Type: Application
    Filed: November 13, 2006
    Publication date: January 10, 2008
    Applicant: Texas Instruments Incorporated
    Inventors: Narendra Mehta, Ajith Varghese, Benjamin Moser
  • Publication number: 20070207572
    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: Application
    Filed: May 8, 2007
    Publication date: September 6, 2007
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Ajith Varghese, Husam Alshareef, Rajesh Khamankar
  • Patent number: 7227201
    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: August 27, 2004
    Date of Patent: June 5, 2007
    Assignee: Texas Instruments Incorporated
    Inventors: Ajith Varghese, Husam Alshareef, Rajesh Khamankar
  • Publication number: 20070054455
    Abstract: The present invention provides, in one aspect, provides a method of manufacturing a microelectronics device 100 that includes depositing a first gate dielectric layer 160 over a substrate 115, subjecting the first gate dielectric layer 160 to a first nitridation process, forming a second gate dielectric layer 165 over the substrate 115 and having a thickness less than a thickness of the first gate dielectric layer 160, and subjecting the first and second gate dielectric layers 160, 165 to a second nitridation process, wherein the first and second nitridation processes are different. The present invention also provides a microelectronics device 100 fabricated in accordance with the method.
    Type: Application
    Filed: September 12, 2005
    Publication date: March 8, 2007
    Applicant: Texas Instruments Inc.
    Inventors: Ajith Varghese, Reima Laaksonen, Terrence Riley
  • Publication number: 20070015347
    Abstract: A method forms a semiconductor device comprising a modifiable strain inducing layer. A semiconductor body is provided. First and second regions of the semiconductor body are identified. A modifiable tensile strain inducing layer is formed over the device within the first and second regions. A mask is then formed that exposes the second region and covers the first region. A material is selected for a modification implant and the selected material is implanted into the second region thereby converting a portion of the modifiable tensile strain inducing layer into a compressive strain inducing layer within the PMOS region.
    Type: Application
    Filed: July 18, 2005
    Publication date: January 18, 2007
    Inventors: Narendra Mehta, Wayne Bather, Ajith Varghese
  • Publication number: 20070004118
    Abstract: A method forms a semiconductor device comprising isolation structures that selectively induce strain into active regions of NMOS and PMOS devices. Form a hard mask layer over a semiconductor body. A resist layer is formed on the hard mask layer that exposes and defines isolation regions. The hard mask layer is patterned and trench regions are formed using the hard mask layer as a mask. An oxide trench liner that induces compressive strain into active regions of the PMOS region is formed within trench regions of the PMOS region. A nitride trench liner that induces tensile strain into active regions of the NMOS region is formed within the NMOS trench regions.
    Type: Application
    Filed: June 29, 2005
    Publication date: January 4, 2007
    Inventors: Ajith Varghese, Narendra Mehta, Jonathan Holt
  • Publication number: 20060043369
    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: Application
    Filed: August 27, 2004
    Publication date: March 2, 2006
    Applicant: Texas Instruments Incorporated
    Inventors: Ajith Varghese, Husam Alshareef, Rajesh Khamankar
  • Publication number: 20060046514
    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: Application
    Filed: August 31, 2004
    Publication date: March 2, 2006
    Applicant: Texas Instruments Incorporated
    Inventors: Husam Alshareef, Rajesh Khamankar, Ajith Varghese, Cathy Chancellor, Anand Krishnan, Malcolm Bevan
  • Patent number: 6924239
    Abstract: The present invention is generally directed towards a method for removing hydrocarbon contamination from a substrate prior to a nitridation step, therein providing for a generally uniform nitridation of the substrate. The method comprises placing the substrate in a process chamber and flowing an oxygen-source gas into the process chamber. A first plasma is formed in the process chamber for a first predetermined amount of time, wherein the hydrocarbons combine with one or more species of the oxygen-source gas in radical form to form product gases. The gases are removed from the process chamber and a nitrogen-source gas is flowed into the process chamber. A second plasma is then formed in the process chamber for a second predetermined amount of time, therein nitriding the substrate in a significantly uniform manner.
    Type: Grant
    Filed: October 14, 2003
    Date of Patent: August 2, 2005
    Assignee: Texas Instruments Incorporated
    Inventors: Hiroaki Niimi, Husam N. Alshareef, Ajith Varghese
  • Publication number: 20050079723
    Abstract: The present invention is generally directed towards a method for removing hydrocarbon contamination from a substrate prior to a nitridation step, therein providing for a generally uniform nitridation of the substrate. The method comprises placing the substrate in a process chamber and flowing an oxygen-source gas into the process chamber. A first plasma is formed in the process chamber for a first predetermined amount of time, wherein the hydrocarbons combine with one or more species of the oxygen-source gas in radical form to form product gases. The gases are removed from the process chamber and a nitrogen-source gas is flowed into the process chamber. A second plasma is then formed in the process chamber for a second predetermined amount of time, therein nitriding the substrate in a significantly uniform manner.
    Type: Application
    Filed: October 14, 2003
    Publication date: April 14, 2005
    Inventors: Hiroaki Niimi, Husam Alshareef, Ajith Varghese
  • Publication number: 20040262701
    Abstract: The present invention provides a method for controlling the gate leakage in a semiconductor device. In one aspect, the method includes placing a semiconductor substrate in a plasma chamber and subjecting a gate dielectric layer located over the semiconductor substrate to a gas mixture including argon and nitrogen under plasma conditions, wherein a gas flow rate of the argon ranges from about 1700 sccm to about 2200 sccm and a flow rate of the nitrogen ranges from about 40 sccm to about 200 sccm.
    Type: Application
    Filed: April 15, 2004
    Publication date: December 30, 2004
    Applicant: Texas Instruments Incorporated
    Inventors: Husam N. Alshareef, Hiroaki Niimi, Rajesh Khamankar, Ajith Varghese