Patents by Inventor Rajan Rajgopal

Rajan Rajgopal 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: 20220149229
    Abstract: A superluminescent light emitting diode (SLED) includes an active layer that includes a set of mixed strain quantum wells. The set of mixed strain quantum wells includes a set of compressive strained quantum wells and a set of tensile strained quantum wells. A potential difference applied across the SLED causes movement of electron carriers and hole carriers towards the active layer. Radiative recombination of electron and hole pairs in the set of compressive strained quantum wells enables emission of laterally polarized light and radiative recombination of electron and hole pairs in the set of tensile strained quantum wells enables emission of vertically polarized light. A combination of the laterally polarized light and vertically polarized light results in the emission of incoherent light from the SLED.
    Type: Application
    Filed: November 12, 2021
    Publication date: May 12, 2022
    Applicant: DENSELIGHT SEMICONDUCTORS PTE LTD
    Inventors: Royston Hogan, Andy Piper, Rajan Rajgopal, Ashish Kumar Rai, Dasa Lakshmi Narayana Dheeraj
  • Patent number: 6815239
    Abstract: Five new methods for the formation of an improved liquid-crystal-on-silicon display are described, in which the device structure is enhanced by the photolithographic building of alignment posts among the mirror pixels of the micro-display. These five methods accommodate the fabrication of an optical interference multilayer, which improves the image quality of the reflected light. These five methods are: Silicon Dioxide Posts by Wet Etching. Amorphous Silicon Posts by Plasma Etching. Silicon Nitride Posts by Plug Filling. Insulation Material Posts by Lift-off. Polyimide Posts by Photosensitive Etching.
    Type: Grant
    Filed: March 5, 1999
    Date of Patent: November 9, 2004
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Sik On Kong, Rajan Rajgopal, George Wong
  • Patent number: 6689653
    Abstract: Methods of protecting, and increasing the thickness of, the oxidized silicon nitride (ON), component of an oxidized silicon nitride on silicon oxide (ONO), layer of a non-volatile memory device, during the hydrofluoric (HF), acid type procedures used for peripheral devices simultaneously fabricated with the non-volatile memory device, has been developed. A first method features a silicon nitride layer located only overlying the ONO layer of the non-volatile memory device, formed prior to HF type pre-clean procedures performed prior to gate oxidation procedures used for peripheral devices. After the gate oxidation procedures the silicon nitride capping layer is selectively removed. A second method features a polysilicon capping layer again located only overlying the ONO layer of the non-volatile memory device, again formed prior to HF type pre-clean procedures.
    Type: Grant
    Filed: June 18, 2003
    Date of Patent: February 10, 2004
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Xavier Teo Leng Seah, Chivukula Subrahmanyam, Rajan Rajgopal
  • Patent number: 6607993
    Abstract: A method is provided for manufacturing an integrated circuit including a substrate with a gate layer and a gate dielectric provided on the substrate. The gate layer is formed into a gate using a process that imposes a charge in the gate dielectric. The substrate, gate, and gate dielectric are irradiated to discharge the charge across the gate dielectric.
    Type: Grant
    Filed: August 19, 2002
    Date of Patent: August 19, 2003
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Ronald Dickinson, Yeow Meng Teo, Dong Xiang Qi, Rajan Rajgopal
  • Patent number: 5882981
    Abstract: After formation of a sandwich over a substrate of a layer of silicon dioxide (3) followed by a layer of silicon (1) having a pad oxide (7) thereon and a patterned silicon nitride layer (9) over the pad oxide, the unmasked portion of the pad oxide and silicon are removed to provide mesas of silicon with silicon nitride thereover and possibly removal of some of the buried oxide layer. A flowable insulator (15), preferably silsesquioxane (H.sub.x SiO.sub.1.5, where x.ltoreq.1, depending upon the level of polymerization) in a contaminant-free, high purity solvent which is later removed during an annealing step, is placed over the exposed surface such that it fills the voids between the mesas of silicon with silicon nitride thereon and extends over the nitride. The flowable insulator, due to its flowability, provides a generally planar surface. The flowable insulator is etched back and a cap oxide (17) is optionally deposited over the etched back insulator layer.
    Type: Grant
    Filed: July 29, 1997
    Date of Patent: March 16, 1999
    Assignee: Texas Instruments Incorporated
    Inventors: Rajan Rajgopal, Kelly J. Taylor, Thomas R. Seha, Keith A. Joyner