Patents by Inventor Rajiv Rastogi

Rajiv Rastogi 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: 7985328
    Abstract: A method and apparatus are described that use cell voltage and/or current as monitor to prevent electrochemical deposition (e.g., electroplating) tools from deplating wafers with no or poor metal (e.g., Cu) seed coverage.
    Type: Grant
    Filed: February 4, 2008
    Date of Patent: July 26, 2011
    Assignee: Intel Corporation
    Inventors: Yang Cao, Yue Ma, Jir-shyr Chen, Rajiv Rastogi
  • Patent number: 7438794
    Abstract: A copper electroplating bath composition and a method of copper electroplating to improve gapfill are provided. The method of electroplating includes providing an aqueous electroplating composition, comprising copper, at least one acid, at least one halogen ion, an additive including an accelerating agent, a suppressing agent, and a suppressing-accelerating agent, and the solution and mixture products thereof; contacting a substrate with the plating composition; and impressing a multi-step waveform potential upon the substrate, wherein the multi-step waveform potential includes an entry step, wherein the entry step includes a first sub-step applying a first current and a second sub-step applying second current, the second current being greater than the first current. The accelerating agent is provided in concentration of greater than 1.
    Type: Grant
    Filed: September 30, 2004
    Date of Patent: October 21, 2008
    Assignee: Intel Corporation
    Inventors: David Jentz, Ramesh Viswanathan, Paul McGregor, Valery Dubin, Rajiv Rastogi
  • Publication number: 20080142363
    Abstract: A method and apparatus are described that use cell voltage and/or current as monitor to prevent electrochemical deposition (e.g., electroplating) tools from deplating wafers with no or poor metal (e.g., Cu) seed coverage.
    Type: Application
    Filed: February 4, 2008
    Publication date: June 19, 2008
    Inventors: Yang Cao, Yue Ma, Jir-shyr Chen, Rajiv Rastogi
  • Patent number: 7371312
    Abstract: A method and apparatus are described that use cell voltage and/or current as monitor to prevent electrochemical deposition (e.g., electroplating) tools from deplating wafers with no or poor metal (e.g., Cu) seed coverage. In one embodiment, the voltage of a plating cell including a reference wafer which has substantially complete Cu seed coverage is measured. A reference resistance of the plating cell with the reference wafer is determined. The voltage of the plating cell including a calibration wafer which has no or insufficient seed coverage at its edge is measured. A calibration resistance of the plating cell with the calibration wafer is determined. An error trigger based on a comparison of the reference resistance with the calibration resistance is selected.
    Type: Grant
    Filed: March 31, 2004
    Date of Patent: May 13, 2008
    Assignee: Intel Corporation
    Inventors: Yang Cao, Yue Ma, Jir-shyr Chen, Rajiv Rastogi
  • Publication number: 20060091018
    Abstract: Embodiments of the invention provide methods for electroplating a substrate that substantially reduce or eliminate protrusions and decrease WID thickness variations. The number of protrusions formed on the plating surface is highly dependent upon the electroplating current density. Embodiments of the invention vary the electroplating current waveform by implementing an initial current step sufficient to fill substrate features and a terminal current step sufficient to achieve the specified plating thickness while suppressing protrusions and within die thickness variations.
    Type: Application
    Filed: December 1, 2005
    Publication date: May 4, 2006
    Inventors: Yang Cao, Vinay Chikarmane, Rajiv Rastogi, Daniel Zierath
  • Publication number: 20060065536
    Abstract: A copper electroplating bath composition and a method of copper electroplating to improve gapfill are provided. The method of electroplating includes providing an aqueous electroplating composition, comprising copper, at least one acid, at least one halogen ion, an additive including an accelerating agent, a suppressing agent, and a suppressing-accelerating agent, and the solution and mixture products thereof; contacting a substrate with the plating composition; and impressing a multi-step waveform potential upon the substrate, wherein the multi-step waveform potential includes an entry step, wherein the entry step includes a first sub-step applying a first current and a second sub-step applying second current, the second current being greater than the first current. The accelerating agent is provided in concentration of greater than 1.
    Type: Application
    Filed: September 30, 2004
    Publication date: March 30, 2006
    Inventors: David Jentz, Ramesh Viswanathan, Paul McGregor, Valery Dubin, Rajiv Rastogi
  • Publication number: 20050285269
    Abstract: A die is provided with an insulation layer and an interconnect. The interconnect has been recrystallized to reduce void content.
    Type: Application
    Filed: June 29, 2004
    Publication date: December 29, 2005
    Inventors: Yang Cao, Robert Wu, Yue Ma, Chia-Hong Jan, Vinay Chikarmane, Rajiv Rastogi
  • Publication number: 20050227381
    Abstract: A method and apparatus are described that use cell voltage and/or current as monitor to prevent electrochemical deposition (e.g., electroplating) tools from deplating wafers with no or poor metal (e.g., Cu) seed coverage.
    Type: Application
    Filed: March 31, 2004
    Publication date: October 13, 2005
    Inventors: Yang Cao, Yue Ma, Jir-shyr Chen, Rajiv Rastogi
  • Publication number: 20040256240
    Abstract: An electroplating system is provided with a rotatable head assembly including a substrate holder to secure a substrate for entry into a bath of electrolyte; and a head tilt mechanism including a stepper motor connected to the rotatable head assembly and configured to control bath entry parameters for optimal surface wetting of the substrate, upon bath entry for electroplating the substrate free of electroplating defects, including, but not limited to, swirl defects.
    Type: Application
    Filed: June 20, 2003
    Publication date: December 23, 2004
    Inventors: David C. Nelsen, Rajiv Rastogi
  • Publication number: 20040188265
    Abstract: Embodiments of the invention provide methods for electroplating a substrate that substantially reduce or eliminate protrusions and decrease WID thickness variations. The number of protrusions formed on the plating surface is highly dependent upon the electroplating current density. Embodiments of the invention vary the electroplating current waveform by implementing an initial current step sufficient to fill substrate features and a terminal current step sufficient to achieve the specified plating thickness while suppressing protrusions and within die thickness variations.
    Type: Application
    Filed: March 25, 2003
    Publication date: September 30, 2004
    Inventors: Yang Cao, Vinay B. Chikarmane, Rajiv Rastogi, Daniel J. Zierath
  • Publication number: 20040069644
    Abstract: A wafer is prepared for electroplating via a spin, rinse and dry process performed on the wafer prior to electroplating. The process may be performed in a standalone tool or may be performed in a preclean module integrated into an electroplating tool.
    Type: Application
    Filed: September 30, 2002
    Publication date: April 15, 2004
    Inventors: David C. Nelsen, Rajiv Rastogi
  • Patent number: 5747879
    Abstract: An improvement in a metal stack used for interconnecting structures in an integrated circuit. The improvement comprises the entrapping in a titanium layer of nitrogen at the interface where the titanium layer contacts a bulk conductor layer such as an aluminum-copper alloy layer. The entrapped nitrogen prevents the formation of any substantial amount of titanium aluminide thereby reducing current densities and also improving the electromigration properties of the stack. As currently preferred, the nitrogen is entrapped in approximately the first 30.ANG. of the titanium layer.
    Type: Grant
    Filed: June 28, 1996
    Date of Patent: May 5, 1998
    Assignee: Intel Corporation
    Inventors: Rajiv Rastogi, Sandra J. Underwood, Harry H. Fujimoto
  • Patent number: 5286678
    Abstract: The present invention generally involves the fabrication of semiconductor devices so as to reduce the active region to interconnect interface resistivity. Fabrication begins by forming active regions on a semiconductor device. Next, a titanium metal of approximately 900 .ANG. thickness is deposited on the semiconductor device. The semiconductor device is then annealed in a single step to form the interconnects.
    Type: Grant
    Filed: September 28, 1992
    Date of Patent: February 15, 1994
    Assignee: Intel Corporation
    Inventor: Rajiv Rastogi