Patents by Inventor Ratnaji Rao Kola

Ratnaji Rao Kola 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).

  • Patent number: 6317948
    Abstract: The specification describes of multilevel printed circuit boards and a process for their manufacture in which capacitors and other passive components are buried between levels of the multilevel board. The capacitor in the multilevel structure is designed so that access is conveniently provided to connect from the parallel plate electrodes of the interlevel capacitor to the board surface or to another board level using plated through hole interconnects.
    Type: Grant
    Filed: April 14, 1999
    Date of Patent: November 20, 2001
    Assignee: Agere Systems Guardian Corp.
    Inventors: Ratnaji Rao Kola, Louis Thomas Manzione, Roderick Kent Watts
  • Patent number: 6075691
    Abstract: A thin film capacitor for use in semiconductor integrated circuit devices such as analog circuits, rf circuits, and dynamic random access memories (DRAMs), and a method for its fabrication, is disclosed. The capacitor has a dielectric thickness less than about 50 nm, a capacitance density of at least about 15 fF/.mu.m.sup.2, and a breakdown field of at least about 1 MV/cm. The dielectric material is a metal oxide of either titanium, niobium, or tantalum. The metal oxide can also contain silicon or nitrogen. The dielectric material is formed over a first electrode by depositing the metal onto the substrate or onto a first electrode formed on the substrate. The metal is then anodically oxidized to form the dielectric material of the desired thickness. A top electrode is then formed over the dielectric layer. The top electrode is a metal that does not degrade the electrical characteristics (e.g. the leakage current or the breakdown voltage) of the dielectric layer.
    Type: Grant
    Filed: August 25, 1997
    Date of Patent: June 13, 2000
    Assignee: Lucent Technologies Inc.
    Inventors: Salvador Duenas, Ratnaji Rao Kola, Henry Y. Kumagai, Maureen Yee Lau, Paul A. Sullivan, King Lien Tai
  • Patent number: 5936831
    Abstract: In accordance with the invention, a thin film capacitor including a dielectric of nitrogen or silicon-doped tantalum oxide and at least one electrode including chromium. Preferably the capacitor is fabricated by anodically oxidizing TaN.sub.x or Ta.sub.2 Si and forming a Cr counterelectrode. The method is fully compatible with MCM processing. It produces anodic Ta.sub.2 O.sub.5 capacitors having exceptionally low leakage currents (<1 nA/cm.sup.2 at 10 V), high breakdown fields (>4 MV/cm) and high capacitance densities (70 nF/cm.sup.2). The devices are stable at 350.degree. C. with excellent capacitor properties and are particularly useful as thin film capacitors of large area (>1 mm.sup.2).
    Type: Grant
    Filed: March 6, 1997
    Date of Patent: August 10, 1999
    Assignee: Lucent Technologies Inc.
    Inventors: Ratnaji Rao Kola, King Lien Tai