Patents by Inventor Ravindranath Droopad

Ravindranath Droopad 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: 20060030098
    Abstract: A method of forming a dielectric layer structure on a supporting semiconductor structure having a first surface comprises providing a first beam of oxide; depositing a first layer of oxide on the first surface of the supporting semiconductor structure using the first beam of oxide, wherein the first layer of oxide has a second surface; terminating the first beam of oxide, and concurrently providing a second beam of oxide, a beam of metal and a beam of oxygen, wherein the first and second beams of oxide are separate and distinct beams of oxide; and depositing a second layer of oxide on the second surface simultaneously using the second beam of oxide, the beam of metal, and the beam of oxygen.
    Type: Application
    Filed: September 30, 2005
    Publication date: February 9, 2006
    Inventors: Ravindranath Droopad, Matthias Passlack
  • Patent number: 6916717
    Abstract: High quality monocrystalline metal oxide layers are grown on a monocrystalline substrate such as a silicon wafer. The monocrystalline metal oxide is grown on the silicon substrate at a temperature low enough to prevent deleterious and simultaneous oxidation of the silicon substrate. After a layer of 1-3 monolayers of the monocrystalline oxide is grown, the growth is stopped and the crystal quality of that layer is improved by a higher temperature anneal. Following the anneal, the thickness of the layer can be increased by restarting the low temperature growth. An amorphous silicon oxide layer can be grown at the interface between the monocrystalline metal oxide layer and the silicon substrate after the thickness of the monocrystalline oxide reaches a few monolayers.
    Type: Grant
    Filed: May 3, 2002
    Date of Patent: July 12, 2005
    Assignee: Motorola, Inc.
    Inventors: Hao Li, Ravindranath Droopad, Daniel S. Marshall, Yi Wei, Xiao M. Hu, Yong Liang
  • Publication number: 20050101159
    Abstract: A dielectric layer comprised of lanthanum, lutetium, and oxygen that is formed between two conductors or a conductor and a substrate. In one embodiment, the dielectric layer is formed over the substrate without the need for an additional interfacial layer. In another embodiment, the dielectric layer is graded with respect to the lanthanum or lutetium content or in the alternative, may include aluminum. In yet another embodiment, an insulating layer is formed between the conductor or substrate and the dielectric layer or between both the conductor and substrate and the dielectric layer. The dielectric layer is preferably formed by molecular beam epitaxy, but can also be formed by atomic layer chemical vapor deposition, physical vapor deposition, organometallic chemical vapor deposition or pulsed laser deposition.
    Type: Application
    Filed: July 21, 2004
    Publication date: May 12, 2005
    Inventor: Ravindranath Droopad
  • Patent number: 6890816
    Abstract: High quality epitaxial layers of monocrystalline perovskite materials (18) can be grown overlying monocrystalline substrates (12) such as gallium arsenide wafers by forming a metal template layer (16) on the monocrystalline substrate. The structure includes a metal-containing layer (16) to mitigate unwanted oxidation of underlying layers and a low-temperature seed layer (19) that prevents degradation of an epitaxial layer (14) during growth of the perovskite layer (18).
    Type: Grant
    Filed: February 7, 2003
    Date of Patent: May 10, 2005
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Yong Liang, Ravindranath Droopad
  • Patent number: 6885065
    Abstract: A ferromagnetic semiconductor structure is provided. The structure includes a monocrystalline semiconductor substrate and a doped titanium oxide anatase layer overlying the semiconductor substrate.
    Type: Grant
    Filed: November 20, 2002
    Date of Patent: April 26, 2005
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Yong Liang, Ravindranath Droopad, Hao Li, Zhiyi Yu
  • Publication number: 20050056210
    Abstract: High quality epitaxial layers of compound semiconductor materials can be grown overlying large silicon wafers by first growing an accommodating buffer layer on a silicon wafer. The accommodating buffer layer is a layer of monocrystalline oxide spaced apart from the silicon wafer by an amorphous interface layer of silicon oxide. The amorphous interface layer dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer. Any lattice mismatch between the accommodating buffer layer and the underlying silicon substrate is taken care of by the amorphous interface layer.
    Type: Application
    Filed: August 5, 2004
    Publication date: March 17, 2005
    Applicant: MOTOROLA
    Inventors: Nada El-Zein, Jamal Ramdani, Kurt Eisenbeiser, Ravindranath Droopad
  • Publication number: 20050023622
    Abstract: Circuit (10) has a dual layer gate dielectric (29) formed over a semiconductor substrate (14). The gate dielectric includes an amorphous layer (40) and a monocrystalline layer (42). The monocrystalline layer typically has a higher dielectric constant than the amorphous layer.
    Type: Application
    Filed: May 14, 2004
    Publication date: February 3, 2005
    Applicant: MOTOROLA
    Inventors: Kurt Eisenbeiser, Jun Wang, Ravindranath Droopad
  • Publication number: 20040232525
    Abstract: High quality epitaxial layers of compound semiconductor materials can be grown overlying large silicon wafers by first growing an accommodating buffer layer on a silicon wafer. The accommodating buffer layer is a layer of monocrystalline oxide spaced apart from the silicon wafer by an amorphous interface layer of silicon oxide. The amorphous interface layer dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer. The accommodating buffer layer is lattice matched to both the underlying silicon wafer and the overlying monocrystalline compound semiconductor layer. Any lattice mismatch between the accommodating buffer layer and the underlying silicon substrate is taken care of by the amorphous interface layer.
    Type: Application
    Filed: June 29, 2004
    Publication date: November 25, 2004
    Applicant: MOTOROLA, INC.
    Inventors: Jamal Ramdani, Ravindranath Droopad, Lyndee L. Hilt, Kurt William Eisenbeiser
  • Patent number: 6806202
    Abstract: A method for removing silicon oxide from a surface of a substrate is disclosed. The method includes depositing material onto the silicon oxide (110) and heating the substrate surface to a sufficient temperature to form volatile compounds including the silicon oxide and the deposited material (120). The method also includes heating the surface to a sufficient temperature to remove any remaining deposited material (130).
    Type: Grant
    Filed: December 3, 2002
    Date of Patent: October 19, 2004
    Assignee: Motorola, Inc.
    Inventors: Xiaoming Hu, James B. Craigo, Ravindranath Droopad, John L. Edwards, Jr., Yong Liang, Yi Wei, Zhiyi Yu
  • Publication number: 20040157357
    Abstract: High quality epitaxial layers of monocrystalline perovskite materials (18) can be grown overlying monocrystalline substrates (12) such as gallium arsenide wafers by forming a metal template layer (16) on the monocrystalline substrate. The structure includes a metal-containing layer (16) to mitigate unwanted oxidation of underlying layers and a low-temperature seed layer (19) that prevents degradation of an epitaxial layer (14) during growth of the perovskite layer (18).
    Type: Application
    Filed: February 7, 2003
    Publication date: August 12, 2004
    Inventors: Yong Liang, Ravindranath Droopad
  • Publication number: 20040150076
    Abstract: High quality epitaxial layers of compound semiconductor materials can be grown overlying large silicon wafers by first growing an accommodating buffer layer on a silicon wafer. The accommodating buffer layer is a layer of monocrystalline oxide spaced apart from the silicon wafer by an amorphous interface layer of silicon oxide. The amorphous interface layer dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer. The accommodating buffer layer is lattice matched to both the underlying silicon wafer and the overlying monocrystalline compound semiconductor layer. Any lattice mismatch between the accommodating buffer layer and the underlying silicon substrate is taken care of by the amorphous interface layer.
    Type: Application
    Filed: February 2, 2004
    Publication date: August 5, 2004
    Applicant: MOTOROLA, INC.
    Inventors: Jamal Ramdani, Ravindranath Droopad, Lyndee L. Hilt, Kurt William Einsebeiser
  • Publication number: 20040149203
    Abstract: High quality epitaxial layers of compound semiconductor materials can be grown overlying large silicon wafers by first growing an accommodating buffer layer on a silicon wafer. The accommodating buffer layer is a layer of monocrystalline oxide spaced apart from the silicon wafer by an amorphous interface layer of silicon oxide. The amorphous interface layer dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer. The accommodating buffer layer is lattice matched to both the underlying silicon wafer and the overlying monocrystalline compound semiconductor layer. Any lattice mismatch between the accommodating buffer layer and the underlying silicon substrate is taken care of by the amorphous interface layer.
    Type: Application
    Filed: February 2, 2004
    Publication date: August 5, 2004
    Applicant: MOTOROLA, INC.
    Inventors: Jamal Ramdani, Ravindranath Droopad, Lyndee L. Hilt, Kurt William Eisenbeiser
  • Publication number: 20040149202
    Abstract: High quality epitaxial layers of compound semiconductor materials can be grown overlying large silicon wafers by first growing an accommodating buffer layer on a silicon wafer. The accommodating buffer layer is a layer of monocrystalline oxide spaced apart from the silicon wafer by an amorphous interface layer of silicon oxide. The amorphous interface layer dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer. The accommodating buffer layer is lattice matched to both the underlying silicon wafer and the overlying monocrystalline compound semiconductor layer. Any lattice mismatch between the accommodating buffer layer and the underlying silicon substrate is taken care of by the amorphous interface layer.
    Type: Application
    Filed: February 2, 2004
    Publication date: August 5, 2004
    Applicant: MOTOROLA, INC.
    Inventors: Jamal Ramdani, Ravindranath Droopad, Lyndee L. Hilt, Kurt William Eisenbeiser
  • Publication number: 20040150003
    Abstract: High quality epitaxial layers of compound semiconductor materials can be grown overlying large silicon wafers by first growing an accommodating buffer layer on a silicon wafer. The accommodating buffer layer is a layer of monocrystalline oxide spaced apart from the silicon wafer by an amorphous interface layer of silicon oxide. The amorphous interface layer dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer. The accommodating buffer layer is lattice matched to both the underlying silicon wafer and the overlying monocrystalline compound semiconductor layer. Any lattice mismatch between the accommodating buffer layer and the underlying silicon substrate is taken care of by the amorphous interface layer.
    Type: Application
    Filed: February 2, 2004
    Publication date: August 5, 2004
    Applicant: MOTOROLA, INC.
    Inventors: Jamal Ramdani, Ravindranath Droopad, Lyndee L. Hilt, Kurt William Einsebeiser
  • Patent number: 6750067
    Abstract: A high quality epitaxial layer of monocrystalline Pb(Zr,Ti)O3 can be grown overlying large silicon wafers by first growing an strontium titanate layer on a silicon wafer. The strontium titanate layer is a monocrystalline layer spaced apart from the silicon wafer by an amorphous interface layer of silicon oxide.
    Type: Grant
    Filed: April 19, 2002
    Date of Patent: June 15, 2004
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Ramoothy Ramesh, Yu Wang, Jeffrey M. Finder, Kurt Eisenbeiser, Zhiyi Yu, Ravindranath Droopad
  • Publication number: 20040106296
    Abstract: A method for removing silicon oxide from a surface of a substrate is disclosed. The method includes depositing material onto the silicon oxide (110) and heating the substrate surface to a sufficient temperature to form volatile compounds including the silicon oxide and the deposited material (120). The method also includes heating the surface to a sufficient temperature to remove any remaining deposited material (130).
    Type: Application
    Filed: December 3, 2002
    Publication date: June 3, 2004
    Inventors: Xiaoming Hu, James B. Craigo, Ravindranath Droopad, John L. Edwards, Yong Liang, Yi Wei, Zhiyi Yu
  • Publication number: 20040097096
    Abstract: High quality epitaxial layers of monocrystalline oxide materials (24) can be grown overlying monocrystalline substrates (22) such as large silicon wafers. The monocrystalline oxide layer (24) comprises a layer of monocrystalline oxide spaced apart from the silicon wafer by an amorphous interface layer (28) of silicon oxide. The amorphous interface layer serves as a decoupling layer between the substrate and the buffer layer so that the substrate and the buffer is crystal-graphically, chemically, and dielectrically decoupled. In addition, high quality epitaxial accommodating buffer layers may be formed overlying vicinal substrates using a low pressure, low temperature, alkaline-earth metal-rich process.
    Type: Application
    Filed: November 19, 2002
    Publication date: May 20, 2004
    Inventors: Yong Liang, Ravindranath Droopad, Xiaoming Hu, Jun Wang, Yi Wei, Zhiyi Yu
  • Publication number: 20040094801
    Abstract: A ferromagnetic semiconductor structure is provided. The structure includes a monocrystalline semiconductor substrate and a doped titanium oxide anatase layer overlying the semiconductor substrate.
    Type: Application
    Filed: November 20, 2002
    Publication date: May 20, 2004
    Applicant: MOTOROLA, INC.
    Inventors: Yong Liang, Ravindranath Droopad, Hao Li, Zhiyi Yu
  • Publication number: 20040079285
    Abstract: High quality epitaxial layers of monocrystalline materials (26) can be grown overlying monocrystalline substrates (22) such as large silicon wafers by forming a compliant substrate for growing the monocrystalline layers. An accommodating buffer layer (24) comprises a layer of monocrystalline oxide spaced apart from a silicon wafer by an amorphous interface layer (28) of silicon oxide. The amorphous interface layer dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer. The growth of the monocrystalline oxide film for accommodating buffer layer (24) is achieved through an automated oxygen delivery system (200) that controls a variety of oxygen control parameters, such as pressure control, ramp control, and flow control. The oxygen delivery system (200) is preferably a dual stage pressure control system (204, 206) with the ability to precisely control the oxygen profile in the growth chamber.
    Type: Application
    Filed: October 24, 2002
    Publication date: April 29, 2004
    Applicant: MOTOROLA, INC.
    Inventors: Hao Li, Ravindranath Droopad, Dirk Jordan, Corey Overgaard, Zhiyi Yu
  • Patent number: 6709989
    Abstract: A method of fabricating a semiconductor structure including the steps of: providing a silicon substrate having a surface; forming by atomic layer deposition a monocrystalline seed layer on the surface of the silicon substrate; and forming by atomic layer deposition one or more layers of a monocrystalline high dielectric constant oxide on the seed layer, where providing a substrate includes providing a substrate having formed thereon a silicon oxide, and wherein forming by atomic layer deposition a seed layer further includes depositing a layer of a metal oxide onto a surface of the silicon oxide, flushing the layer of metal oxide with an inert gas, and reacting the metal oxide and the silicon oxide to form a monocrystalline silicate.
    Type: Grant
    Filed: June 21, 2001
    Date of Patent: March 23, 2004
    Assignee: Motorola, Inc.
    Inventors: Jamal Ramdani, Ravindranath Droopad, Zhiyi Yu