Patents by Inventor Srikanth B. Samavedam

Srikanth B. Samavedam 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: 20040191974
    Abstract: A method of fabricating a MOS transistor that comprises a dual-metal gate that is formed from heterotypical metals. A gate dielectric (34), such as HfO2, is deposited on a semiconductor substrate. A sacrificial layer (35), is next deposited over the gate dielectric. The sacrificial layer is patterned so that the gate dielectric over a first (pMOS, for example) area (32) of the substrate is exposed and gate dielectric over a second (nMOS, for example) area (33) of the substrate continues to be protected by the sacrificial layer. A first gate conductor material (51) is deposited over the remaining sacrificial area and over the exposed gate dielectric. The first gate conductor material is patterned so that first gate conductor material over the second area of the substrate is etched away. The sacrificial layer over the second area prevents damage to the underlying dielectric material as the first gate conductor material is removed.
    Type: Application
    Filed: March 27, 2003
    Publication date: September 30, 2004
    Inventors: David C. Gilmer, Srikanth B. Samavedam, Philip J. Tobin
  • Patent number: 6790719
    Abstract: A semiconductor device has a P channel gate stack comprising a first metal type and a second metal type over the first metal type and an N channel gate stack comprising the second metal type in direct contact with the a gate dielectric. The N channel gate stack and a portion of the P channel gate stack are etched by a dry etch. The etch of P channel gate stack is completed with a wet etch. The wet etch is very selective to the gate dielectric and to the second metal type so that the N channel transistor is not adversely effected by completing the etch of the P channel gate stack.
    Type: Grant
    Filed: April 9, 2003
    Date of Patent: September 14, 2004
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Olubunmi O. Adetutu, Eric D. Luckowski, Srikanth B. Samavedam, Arturo M. Martinez, Jr.
  • Publication number: 20040023478
    Abstract: A first gate (120) and a second gate (122) are preferably PMOS and NMOS transistors, respectively, formed in an n-type well (104) and a p-type well (106). In a preferred embodiment, first gate (120) includes a first metal layer (110) of titanium nitride on a gate dielectric (108), a second metal layer (114) of tantalum silicon nitride and a silicon containing layer (116) of polysilicon.. Second gate (122) includes second metal layer (114) of a tantalum silicon nitride layer on the gate dielectric (108) and a silicon containing layer (116) of polysilicon. First spacers (124) are formed adjacent the sidewalls of the gates to protect the metals from chemistries used to remove photoresist masks during implant steps. Since the chemistries used are selective to polysilicon, the spacers (124) need not protect the polysilicon capping layers, thereby increasing the process margin of the spacer etch process. The polysilicon cap also facilitates silicidation of the gates.
    Type: Application
    Filed: July 31, 2002
    Publication date: February 5, 2004
    Inventors: Srikanth B. Samavedam, Philip J. Tobin
  • Patent number: 6514808
    Abstract: A transistor device (19) utilizes a high K dielectric (24) between a gate electrode (16) and a substrate (12). The high K dielectric (24) is etched under the gate electrode (16) so that there is an area between the gate electrode (16) and the substrate (12) that is void of high K dielectric (24). The source/drains extensions (28 and 30) are minimized to extend substantially in alignment with the edge of gate dielectric (24) to reduce overlap with the gate dielectric (24). This results in reduced capacitance between the gate and the source/drain extensions. The void areas (20 and 22) between the gate and the substrate (12) may remain void or may be filled with a low K dielectric, or at least a dielectric that is not high K.
    Type: Grant
    Filed: November 30, 2001
    Date of Patent: February 4, 2003
    Assignee: Motorola, Inc.
    Inventors: Srikanth B. Samavedam, Christopher C. Hobbs, William J. Taylor, Jr.
  • Patent number: 6475841
    Abstract: A transistor structure includes a retrograde gate structure (112) that is narrower at the end that interfaces with the gate dielectric (120) than it is at the opposite end and method for manufacture of such a structure. The retrograde gate structure (112) is formed by depositing a layer of gate material (104) that has varying composition in the vertical direction. The differentiation in composition causes varying lateral etch rate characteristics along the vertical direction of the gate structure (112) such that increased etching of the gate material (104) occurs near the interface with the gate dielectric layer (102).
    Type: Grant
    Filed: June 2, 2000
    Date of Patent: November 5, 2002
    Assignee: Motorola, Inc.
    Inventors: William J. Taylor, Jr., Srikanth B. Samavedam, Nigel Cave
  • Patent number: 6423632
    Abstract: A semiconductor device and a process for forming the device includes a conductor that overlies an insulating layer. In one embodiment, the conductor includes a first conductive portion, a second conductive portion, and a third conductive portion. The second conductive portion lies between the first and third conductive portions. The first conductive portion includes a first element, and the third conductive portion includes a metal and silicon without a significant amount of the first element. In another embodiment, the conductor is a gate electrode or a capacitor electrode. The conductor includes a first conductive portion, a second conductive portion, a third conductive portion, and a fourth conductive portion. The second conductive portion lies between the first and third conductive portions and has a different composition compared to the first, third, and fourth conductive portion.
    Type: Grant
    Filed: July 21, 2000
    Date of Patent: July 23, 2002
    Assignee: Motorola, Inc.
    Inventors: Srikanth B. Samavedam, Philip J. Tobin, William J. Taylor, Jr.
  • Patent number: 6320784
    Abstract: A memory cell (101), its method of formation, and operation are disclosed. In accordance with one embodiment, the memory cell (101) comprises a first and second current carrying electrode (12) a control electrode (19), and doped discontinuous storage elements (17). In accordance with an alternative embodiment, memory cell programming is accomplished by removing or adding an average of approximately at least a first charge (30, 62, 64), which can be electron(s) or hole(s) from each of the doped discontinuous storage elements (17).
    Type: Grant
    Filed: March 14, 2000
    Date of Patent: November 20, 2001
    Assignee: Motorola, Inc.
    Inventors: Ramachandran Muralidhar, Sucharita Madhukar, Bo Jiang, Bruce E. White, Srikanth B. Samavedam, David L. O'Meara, Michael Alan Sadd
  • Patent number: 6039803
    Abstract: A method of processing semiconductor materials, including providing a monocrystalline silicon substrate having a (001) crystallographic surface orientation; off-cutting the substrate to an orientation from about 2.degree. to about 6.degree. offset towards the [110] direction; and epitaxially growing a relaxed graded layer of a crystalline GeSi on the substrate. A semiconductor structure including a monocrystalline silicon substrate having a (001) crystallographic surface orientation, the substrate being off-cut to an orientation from about 2.degree. to about 6.degree. offset towards the [110] direction; and a relaxed graded layer of a crystalline GeSi which is epitaxially grown on the substrate.
    Type: Grant
    Filed: February 27, 1997
    Date of Patent: March 21, 2000
    Assignee: Massachusetts Institute of Technology
    Inventors: Eugene A. Fitzgerald, Srikanth B. Samavedam