Patents by Inventor Sirish K. Reddy

Sirish K. Reddy 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: 9018103
    Abstract: A method for etching features in a stack is provided. A combination hardmask is formed by forming a first hardmask layer comprising carbon or silicon oxide over the stack, forming a second hardmask layer comprising metal over the first hardmask layer, and patterning the first and second hardmask layers. The stack is etched through the combination hardmask.
    Type: Grant
    Filed: September 26, 2013
    Date of Patent: April 28, 2015
    Assignee: Lam Research Corporation
    Inventors: Joydeep Guha, Sirish K. Reddy, Kaushik Chattopadhyay, Thomas W. Mountsier, Aaron Eppler, Thorsten Lill, Vahid Vahedi, Harmeet Singh
  • Publication number: 20150093908
    Abstract: Methods of forming high etch selectivity, low stress ashable hard masks using plasma enhanced chemical vapor deposition are provided. In certain embodiments, the methods involve pulsing low frequency radio frequency power while keeping high frequency radio frequency power constant during deposition of the ashable hard mask using a dual radio frequency plasma source. According to various embodiments, the low frequency radio frequency power can be pulsed between non-zero levels or by switching the power on and off. The resulting deposited highly selective ashable hard mask may have decreased stress due to one or more factors including decreased ion and atom impinging on the ashable hard mask and lower levels of hydrogen trapped in the ashable hard mask.
    Type: Application
    Filed: April 8, 2014
    Publication date: April 2, 2015
    Applicant: Lam Research Corporation
    Inventors: Sirish K. Reddy, Chunhai Ji, Xinyi Chen, Pramod Subramonium
  • Publication number: 20150093915
    Abstract: Provided are methods of forming ashable hard masks (AHMs) with high etch selectivity and low hydrogen content using plasma enhanced chemical vapor deposition. Methods involve exposing a first layer to be etched on a semiconductor substrate to a carbon source and sulfur source, and generating a plasma to deposit a sulfur-doped AHM or amorphous carbon-based film on the first layer.
    Type: Application
    Filed: May 5, 2014
    Publication date: April 2, 2015
    Applicant: Lam Research Corporation
    Inventors: Sirish K. Reddy, Alice G. Hollister, Thorsten Lill
  • Publication number: 20150087154
    Abstract: A method for etching features in a stack is provided. A combination hardmask is formed by forming a first hardmask layer comprising carbon or silicon oxide over the stack, forming a second hardmask layer comprising metal over the first hardmask layer, and patterning the first and second hardmask layers. The stack is etched through the combination hardmask.
    Type: Application
    Filed: September 26, 2013
    Publication date: March 26, 2015
    Inventors: Joydeep GUHA, Sirish K. REDDY, Kaushik CHATTOPADHYAY, Thomas W. MOUNTSIER, Aaron EPPLER, Thorsten LILL, Vahid VAHEDI, Harmeet SINGH
  • Patent number: 8512818
    Abstract: A highly tensile dielectric layer is generated on a heat sensitive substrate while not exceeding thermal budget constraints. Cascaded ultraviolet (UV) irradiation is used to produce highly tensile films to be used, for example, in strained NMOS transistor architectures. Successive UV radiation of equal or shorter wavelengths with variable intensity and duration selectively breaks bonds in the Si—N matrix and minimizes shrinkage and film relaxation. Higher tensile stress than a non-cascaded approach may be obtained.
    Type: Grant
    Filed: June 1, 2012
    Date of Patent: August 20, 2013
    Assignee: Novellus Systems, Inc.
    Inventors: Bhadri Varadarajan, Gengwei Jiang, Sirish K. Reddy, James S. Sims
  • Patent number: 8211510
    Abstract: A highly tensile dielectric layer is generated on a heat sensitive substrate while not exceeding thermal budget constraints. Cascaded ultraviolet (UV) irradiation is used to produce highly tensile films to be used, for example, in strained NMOS transistor architectures. Successive UV radiation of equal or shorter wavelengths with variable intensity and duration selectively breaks bonds in the Si—N matrix and minimizes shrinkage and film relaxation. Higher tensile stress than a non-cascaded approach may be obtained.
    Type: Grant
    Filed: August 31, 2007
    Date of Patent: July 3, 2012
    Assignee: Novellus Systems, Inc.
    Inventors: Bhadri Varadarajan, Gengwei Jiang, Sirish K. Reddy, James S. Sims