Patents by Inventor Sriram Seshagiri

Sriram Seshagiri 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: 6199506
    Abstract: A plasma-enhanced chemical vapor deposition system includes a balancing inductor in the circuit path between the radio frequency generator and the “showerhead” that is used to introduce reactant gases to the system. The balancing inductor reduces the resonant frequency of the circuit to a level below the frequency of the signal produced by the radio frequency generator. Since the effective capacitance of the showerhead electrode varies monotonically with the power input to the plasma, fluctuations in the power delivered to the plasma will be self-correcting the system will be stabilized. For example, a drop in the power to the plasma will reduce the resonant frequency, but the corresponding reduction in the effective capacitance of the showerhead electrode will tend to increase the resonant frequency, thereby offsetting the change and stabilizing the system.
    Type: Grant
    Filed: June 30, 1999
    Date of Patent: March 13, 2001
    Assignee: Novellus Systems, Inc.
    Inventors: Stephen Hilliker, Viral Hazari, Sriram Seshagiri, Zia Karim