Patents by Inventor Rajitha Vemuri

Rajitha Vemuri 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).

  • Methods for controlling clamping of insulator-type substrate on electrostatic-type substrate support structure
    Patent number: 10923379
    Abstract: An insulator-type substrate is positioned on a support surface of a substrate support structure in exposure to a plasma. An initial clamping voltage is applied to an electrode within the substrate support structure to rapidly accumulate electrical charge on the support surface to hold the substrate. A backside cooling gas is flowed to a region between the substrate and the support surface, and a leak rate of the backside cooling gas is monitored. A steady clamping voltage is applied to the electrode, and the steady clamping voltage is adjusted in a step-wise manner to maintain the monitored leak rate of the backside cooling gas at just less than a maximum allowable leak rate. Or, a pulsed clamping voltage is applied to the electrode, and the pulsed clamping voltage is adjusted to maintain the monitored leak rate of the backside cooling gas at just less than the maximum allowable leak rate.
    Type: Grant
    Filed: February 15, 2017
    Date of Patent: February 16, 2021
    Assignee: Lam Research Corporation
    Inventors: Chin-Yi Liu, Daniel Lai, Rajitha Vemuri, Padma Gopalakrishnan
  • Methods for Controlling Clamping of Insulator-Type Substrate on Electrostatic-Type Substrate Support Structure
    Publication number: 20180233393
    Abstract: An insulator-type substrate is positioned on a support surface of a substrate support structure in exposure to a plasma. An initial clamping voltage is applied to an electrode within the substrate support structure to rapidly accumulate electrical charge on the support surface to hold the substrate. A backside cooling gas is flowed to a region between the substrate and the support surface, and a leak rate of the backside cooling gas is monitored. A steady clamping voltage is applied to the electrode, and the steady clamping voltage is adjusted in a step-wise manner to maintain the monitored leak rate of the backside cooling gas at just less than a maximum allowable leak rate. Or, a pulsed clamping voltage is applied to the electrode, and the pulsed clamping voltage is adjusted to maintain the monitored leak rate of the backside cooling gas at just less than the maximum allowable leak rate.
    Type: Application
    Filed: February 15, 2017
    Publication date: August 16, 2018
    Inventors: Chin-Yi Liu, Daniel Lai, Rajitha Vemuri, Padma Gopalakrishnan