Patents by Inventor Tat Ngai

Tat Ngai 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: 20150340228
    Abstract: A germanium-containing semiconductor device and a method for forming a germanium-containing semiconductor device are described. The method includes providing a germanium-containing substrate, depositing a silicon-containing interface layer on the germanium-containing substrate, depositing an aluminum-containing diffusion barrier layer on the silicon-containing interface layer, and depositing a high-k layer on the aluminum-containing diffusion barrier layer. The germanium-containing semiconductor device includes a germanium-containing substrate, a silicon-containing interface layer on the germanium-containing substrate, an aluminum-containing diffusion barrier layer on the silicon-containing interface layer, and a high-k layer on the aluminum-containing diffusion barrier layer.
    Type: Application
    Filed: May 14, 2015
    Publication date: November 26, 2015
    Inventors: Kandabara N. Tapily, David L. O'Meara, Tat Ngai
  • Patent number: 8237195
    Abstract: A field effect transistor device having a strained semiconductor channel region overlying a heterostructure-semiconductor on a metal substrate includes a first semiconductor layer overlying a first metal layer. The first semiconductor layer has a first semiconductor material and a second semiconductor material in a relaxed heterostructure and is heavily doped. A second semiconductor layer overlies the first semiconductor layer and has a first semiconductor material and a second semiconductor material in a relaxed heterostructure. The second semiconductor layer is more lightly doped than the first semiconductor layer. A trench extends into the second semiconductor layer and a channel region has a strained layer of the first semiconductor material adjacent a trench sidewall. The strained channel region provides enhanced carrier mobility and improves performance of the field effect transistor.
    Type: Grant
    Filed: October 9, 2008
    Date of Patent: August 7, 2012
    Assignee: Fairchild Semiconductor Corporation
    Inventors: Tat Ngai, Qi Wang, Joelle Sharp
  • Publication number: 20120196414
    Abstract: A method for forming a semiconductor device includes forming a graded silicon-germanium (SiGe) layer overlying a silicon substrate, a concentration of germanium increasing with a thickness of the graded silicon germanium layer. A first relaxed SiGe layer is formed over the graded SiGe layer, and a second relaxed SiGe layer overlying the first relaxed SiGe layer. The second relaxed SiGe layer has a lower conductivity than the first relaxed SiGe layer. The method also includes forming a field effect transistor having a trench extending into the second relaxed SiGe layer and a channel region that includes a layer of strained silicon to enable enhanced carrier mobility. A top conductor layer is formed overlying the second relaxed SiGe layer, and then the silicon substrate and the graded SiGe layer are removed. A bottom conductor layer is formed underlying the first relaxed SiGe layer.
    Type: Application
    Filed: April 11, 2012
    Publication date: August 2, 2012
    Inventors: Tat Ngai, Qi Wang, Joelle Sharp
  • Patent number: 8039877
    Abstract: A method of forming a field effect transistor having a heavily doped p-type (110) semiconductor layer over a metal substrate starts with providing a heavily doped p-type (110) silicon layer, and forming a lightly doped p-type (110) silicon layer on the P heavily doped-type (110) silicon layer. The method also includes forming a p-channel MOSFET which has a channel region along a (110) crystalline plane in the lightly doped p-type (110) silicon layer to allow a current conduction in a <110> direction. The p-channel MOSFET also includes a gate dielectric layer having a high dielectric constant material lining the (110) crystalline plane. The method further includes forming a top conductor layer overlying the lightly doped p-type (110) silicon layer and a bottom conductor layer underlying the heavily doped p-type (110) silicon layer.
    Type: Grant
    Filed: September 9, 2008
    Date of Patent: October 18, 2011
    Assignee: Fairchild Semiconductor Corporation
    Inventors: Tat Ngai, Qi Wang
  • Publication number: 20100078682
    Abstract: A field effect transistor device having a strained semiconductor channel region overlying a heterostructure-semiconductor on a metal substrate includes a first semiconductor layer overlying a first metal layer. The first semiconductor layer has a first semiconductor material and a second semiconductor material in a relaxed heterostructure and is heavily doped. A second semiconductor layer overlies the first semiconductor layer and has a first semiconductor material and a second semiconductor material in a relaxed heterostructure. The second semiconductor layer is more lightly doped than the first semiconductor layer. A trench extends into the second semiconductor layer and a channel region has a strained layer of the first semiconductor material adjacent a trench sidewall. The strained channel region provides enhanced carrier mobility and improves performance of the field effect transistor.
    Type: Application
    Filed: October 9, 2008
    Publication date: April 1, 2010
    Inventors: Tat Ngai, Qi Wang, Joelle Sharp
  • Publication number: 20100059797
    Abstract: A method of forming a field effect transistor having a heavily doped p-type (110) semiconductor layer over a metal substrate starts with providing a heavily doped p-type (110) silicon layer, and forming a lightly doped p-type (110) silicon layer on the P heavily doped-type (110) silicon layer. The method also includes forming a p-channel MOSFET which has a channel region along a (110) crystalline plane in the lightly doped p-type (110) silicon layer to allow a current conduction in a <110> direction. The p-channel MOSFET also includes a gate dielectric layer having a high dielectric constant material lining the (110) crystalline plane. The method further includes forming a top conductor layer overlying the lightly doped p-type (110) silicon layer and a bottom conductor layer underlying the heavily doped p-type (110) silicon layer.
    Type: Application
    Filed: September 9, 2008
    Publication date: March 11, 2010
    Inventors: TAT NGAI, QI WANG
  • Publication number: 20060076046
    Abstract: In certain embodiments, a thermoelectric device apparatus includes a plurality of laterally spaced-apart electrodes disposed upon a supporting structure, and at least one complementary pair of thermoelectric elements, each thermoelectric element coupling an electrode to a laterally adjacent electrode. Such a structure reduces the need for solder joints or other structures or mechanisms to attach multiple substrates, components, or assemblies together to form a thermoelectric device.
    Type: Application
    Filed: May 6, 2005
    Publication date: April 13, 2006
    Inventors: Uttam Ghoshal, Tat Ngai, Srikanth Samavedam, Zhengmao Ye, Andrew Miner
  • Publication number: 20050150539
    Abstract: A vertical, monolithic, thin-film thermoelectric device is described. Thermoelectric elements of opposing conductivity types may be coupled electrically in series and thermally in parallel by associated electrodes on a single substrate, reducing the need for mechanisms to attach multiple substrates or components. Phonon transport may be separated from electron transport in a thermoelectric element. A thermoelectric element may have a thickness less than an associated thermalization length. An insulating film between an electrode having a first temperature and an electrode having a second temperature may be a low-thermal conductivity material, a low-k, or ultra-low-k dielectric. Phonon thermal conductivity between a thermoelectric element and an electrode may be reduced without a significant reduction in electron thermal conductivity, as compared to other thermoelectric devices. A phonon conduction impeding material may be included in regions coupling an electrode to an associated thermoelectric element (e.g.
    Type: Application
    Filed: December 23, 2004
    Publication date: July 14, 2005
    Inventors: Uttam Ghoshal, Srikanth Samavedam, Tat Ngai, Andrew Miner
  • Publication number: 20050150535
    Abstract: A vertical, monolithic, thin-film thermoelectric device is described. Thermoelectric elements of opposing conductivity types may be coupled electrically in series and thermally in parallel by associated electrodes on a single substrate, reducing the need for mechanisms to attach multiple substrates or components. Phonon transport may be separated from electron transport in a thermoelectric element. A thermoelectric element may have a thickness less than an associated thermalization length. An insulating film between an electrode having a first temperature and an electrode having a second temperature may be a low-thermal conductivity material, a low-k, or ultra-low-k dielectric. Phonon thermal conductivity between a thermoelectric element and an electrode may be reduced without a significant reduction in electron thermal conductivity, as compared to other thermoelectric devices. A phonon conduction impeding material may be included in regions coupling an electrode to an associated thermoelectric element (e.g.
    Type: Application
    Filed: December 23, 2004
    Publication date: July 14, 2005
    Inventors: Srikanth Samavedam, Uttam Ghoshal, Tat Ngai
  • Publication number: 20050150536
    Abstract: A vertical, monolithic, thin-film thermoelectric device is described. Thermoelectric elements of opposing conductivity types may be coupled electrically in series and thermally in parallel by associated electrodes on a single substrate, reducing the need for mechanisms to attach multiple substrates or components. Phonon transport may be separated from electron transport in a thermoelectric element. A thermoelectric element may have a thickness less than an associated thermalization length. An insulating film between an electrode having a first temperature and an electrode having a second temperature may be a low-thermal conductivity material, a low-k, or ultra-low-k dielectric. Phonon thermal conductivity between a thermoelectric element and an electrode may be reduced without a significant reduction in electron thermal conductivity, as compared to other thermoelectric devices. A phonon conduction impeding material may be included in regions coupling an electrode to an associated thermoelectric element (e.g.
    Type: Application
    Filed: December 23, 2004
    Publication date: July 14, 2005
    Inventors: Tat Ngai, Srikanth Samavedam, Uttam Ghoshal
  • Patent number: 6518106
    Abstract: A semiconductor device with dual gate electrodes and its method of formation is taught. A first metal/silicon gate stack and a first gate dielectric are formed over a first doped region. The metal/gate stack comprises a metal portion over the first gate dielectric and a first gate portion over the metal portion. A silicon gate and a second gate dielectric are formed over the second doped region. In one embodiment, the first and second gate portions are P+ doped silicon germanium and the metal portion is TaSiN. In another embodiment, the first and second gate portions are N+ doped polysilicon and the metal portion is TaSiN.
    Type: Grant
    Filed: May 26, 2001
    Date of Patent: February 11, 2003
    Assignee: Motorola, Inc.
    Inventors: Tat Ngai, Bich-Yen Nguyen, Vidya S. Kaushik, Jamie K. Schaeffer
  • Publication number: 20020175384
    Abstract: A semiconductor device with dual gate electrodes and its method of formation is taught. A first metal/silicon gate stack and a first gate dielectric are formed over a first doped region. The metal/gate stack comprises a metal portion over the first gate dielectric and a first gate portion over the metal portion. A silicon gate and a second gate dielectric are formed over the second doped region. In one embodiment, the first and second gate portions are P+ doped silicon germanium and the metal portion is TaSiN. In another embodiment, the first and second gate portions are N+ doped polysilicon and the metal portion is TaSiN.
    Type: Application
    Filed: May 26, 2001
    Publication date: November 28, 2002
    Inventors: Tat Ngai, Bich-Yen Nguyen, Vidya S. Kaushik, James K. Schaeffer