Patents by Inventor Huajie Chen

Huajie Chen 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: 20040242006
    Abstract: The present invention provides a method of fabricating a SiGe-on-insulator substrate in which lattice engineering is employed to decouple the interdependence between SiGe thickness, Ge fraction and strain relaxation. The method includes providing a SiGe-on-insulator substrate material comprising a SiGe alloy layer having a selected in-plane lattice parameter, a selected thickness parameter and a selected Ge content parameter, wherein the selected in-plane lattice parameter has a constant value and one or both of the other parameters, i.e., thickness or Ge content, have adjustable values; and adjusting one or both of the other parameters to final selected values, while maintaining the selected in-plane lattice parameter. The adjusting is achieved utilizing either a thinning process or a thermal dilution process depending on which parameters are fixed and which are adjustable.
    Type: Application
    Filed: May 30, 2003
    Publication date: December 2, 2004
    Applicant: International Business Machines Corporation
    Inventors: Stephen W. Bedell, Huajie Chen, Keith E. Fogel, Devendra K. Sadana
  • Publication number: 20040171205
    Abstract: High performance (surface channel) CMOS devices with a mid-gap work function metal gate are disclosed wherein an epitaxial layer is used for a threshold voltage Vt adjust/decrease for the PFET area, for large Vt reductions (˜500 mV), as are required by CMOS devices with a mid-gap metal gate. The present invention provides counter doping using an in situ B doped epitaxial layer or a B and C co-doped epitaxial layer, wherein the C co-doping provides an additional degree of freedom to reduce the diffusion of B (also during subsequent activation thermal cycles) to maintain a shallow B profile, which is critical to provide a surface channel CMOS device with a mid-gap metal gate while maintaining good short channel effects. The B diffusion profiles are satisfactorily shallow, sharp and have a high B concentration for devices with mid-gap metal gates, to provide and maintain a thin, highly doped B layer under the gate oxide.
    Type: Application
    Filed: March 8, 2004
    Publication date: September 2, 2004
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Anda C. Mocuta, Meikei Ieong, Ricky S. Amos, Diane C. Boyd, Dan M. Mocuta, Huajie Chen
  • Patent number: 6780695
    Abstract: A method of forming a BiCMOS integrated circuit having a raised extrinsic base is provided. The method includes first forming a polysilicon layer atop a surface of a gate dielectric which is located atop a substrate having device areas for forming at least one bipolar transistor and device areas for forming at least one complementary metal oxide semiconductor (CMOS) transistor. The polysilicon layer is then patterned to provide a sacrificial polysilicon layer over the device areas for forming the at least one bipolar transistor and its surrounding areas, while simultaneously providing at least one gate conductor in the device areas for forming at least one CMOS transistor. At least one pair of spacers are then formed about each of the at least one gate conductor and then a portion of the sacrificial polysilicon layer over the bipolar device areas are selectively removed to provide at least one opening in the bipolar device area.
    Type: Grant
    Filed: April 18, 2003
    Date of Patent: August 24, 2004
    Assignee: International Business Machines Corporation
    Inventors: Huajie Chen, Seshadri Subbanna, Basanth Jagannathan, Gregory G. Freeman, David C. Ahlgren, David Angell, Kathryn T. Schonenberg, Kenneth J. Stein, Fen F. Jamin
  • Patent number: 6777302
    Abstract: A method of fabricating a high-performance, raised extrinsic base HBT having a narrow emitter width is provided. In accordance with the method, a patterned nitride pedestal region and inner spacers are employed to reduce the width of an emitter opening. The reduced width is achieved without the need of using advanced lithographic tools and/or advanced photomasks.
    Type: Grant
    Filed: June 4, 2003
    Date of Patent: August 17, 2004
    Assignee: International Business Machines Corporation
    Inventors: Huajie Chen, David Angell, Seshadri Subbanna
  • Publication number: 20040137670
    Abstract: A self-aligned oxide mask is formed utilizing differential oxidation rates of different materials. The self-aligned oxide mask is formed on a CVD grown base NPN base layer which compromises single crystal Si (or Si/SiGe) at active area and polycrystal Si (or Si/SiGe) on the field. The self-aligned mask is fabricated by taking advantage of the fact that poly Si (or Si/SiGe) oxidizes faster than single crystal Si (or Si/SiGe). An oxide film is formed over both the poly Si (or Si/siGe) and the single crystal Si (or Si/siGe) by using an thermal oxidation process to form a thick oxidation layer over the poly Si (or Si/siGe) and a thin oxidation layer over the single crystal Si (or Si/siGe), followed by a controlled oxide etch to remove the thin oxidation layer over the single crystal Si (or Si/siGe) while leaving the self-aligned oxide mask layer over the poly Si (or Si/siGe). A raised extrinsic base is then formed following the self-aligned mask formation.
    Type: Application
    Filed: January 15, 2003
    Publication date: July 15, 2004
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Huajie Chen, Kathryn T. Schonenberg, Gregory G. Freeman, Andreas D. Stricker, Jae-Sung Rieh
  • Patent number: 6762469
    Abstract: High performance (surface channel) CMOS devices with a mid-gap work function metal gate are disclosed wherein an epitaxial layer is used for a threshold voltage Vt adjust/decrease for the PFET area, for large Vt reductions (˜500 mV), as are required by CMOS devices with a mid-gap metal gate. The present invention provides counter doping using an in situ B doped epitaxial layer or a B and C co-doped epitaxial layer, wherein the C co-doping provides an additional degree of freedom to reduce the diffusion of B (also during subsequent activation thermal cycles) to maintain a shallow B profile, which is critical to provide a surface channel CMOS device with a mid-gap metal gate while maintaining good short channel effects. The B diffusion profiles are satisfactorily shallow, sharp and have a high B concentration for devices with mid-gap metal gates, to provide and maintain a thin, highly doped B layer under the gate oxide.
    Type: Grant
    Filed: April 19, 2002
    Date of Patent: July 13, 2004
    Assignee: International Business Machines Corporation
    Inventors: Anda C. Mocuta, Meikei Ieong, Ricky S. Amos, Diane C. Boyd, Dan M. Mocuta, Huajie Chen
  • Patent number: 6749684
    Abstract: A method is disclosed for forming an epitaxial layer on a front side of a substrate formed of a monocrystalline material, using a chemical vapor deposition system. In this method, a plurality of gettering wafers formed of a gettering material are arranged in the CVD system, such that the front side of each substrate is facing one of the gettering wafers. Impurities present in the CVD system during formation of the epitaxial layer are gettered by the gettering wafers. Alternatively, a layer of a gettering material is deposited on a back side of each of the plurality of substrates, and the substrates are arranged such that the front side of each substrate is facing the backside of another of the substrates. In another embodiment, a layer of a gettering material is deposited on an interior surface of the CVD system. Impurities removed from the CVD system during epitaxial formation include oxygen, water vapor and other oxygen-containing contaminants.
    Type: Grant
    Filed: June 10, 2003
    Date of Patent: June 15, 2004
    Assignee: International Business Machines Corporation
    Inventors: Huajie Chen, Dan Mocuta, Richard J. Murphy, Paul Ronsheim, David Rockwell
  • Publication number: 20030197230
    Abstract: High performance (surface channel) CMOS devices with a mid-gap work function metal gate are disclosed wherein an epitaxial layer is used for a threshold voltage Vt adjust/decrease for the PFET area, for large Vt reductions (˜500 mV), as are required by CMOS devices with a mid-gap metal gate. The present invention provides counter doping using an in situ B doped epitaxial layer or a B and C co-doped epitaxial layer, wherein the C co-doping provides an additional degree of freedom to reduce the diffusion of B (also during subsequent activation thermal cycles) to maintain a shallow B profile, which is critical to provide a surface channel CMOS device with a mid-gap metal gate while maintaining good short channel effects. The B diffusion profiles are satisfactorily shallow, sharp and have a high B concentration for devices with mid-gap metal gates, to provide and maintain a thin, highly doped B layer under the gate oxide.
    Type: Application
    Filed: April 19, 2002
    Publication date: October 23, 2003
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Anda C. Mocuta, Meikei Ieong, Ricky S. Amos, Diane C. Boyd, Dan M. Mocuta, Huajie Chen