Patents by Inventor Praburam Gopalraja

Praburam Gopalraja 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: 7659204
    Abstract: A method and resultant produce of forming barrier layer based on ruthenium tantalum in a via or other vertical interconnect structure through a dielectric layer in a multi-level metallization. The RuTa layer in a RuTa/RuTaN bilayer, which may form discontinuous islands, is actively oxidized, preferably in an oxygen plasma, to thereby bridge the gaps between the islands. Alternatively, ruthenium tantalum oxide is reactive sputtered onto the RuTaN or directly onto the underlying dielectric by plasma sputtering a RuTa target in the presence of oxygen.
    Type: Grant
    Filed: March 26, 2007
    Date of Patent: February 9, 2010
    Assignee: Applied Materials, Inc.
    Inventors: Xianmin Tang, Hua Chung, Rongjun Wang, Praburam Gopalraja, Jick M. Yu, Jenn Yue Wang
  • Publication number: 20090233438
    Abstract: A magnetron sputter reactor for sputtering deposition materials such as tantalum, tantalum nitride and copper, for example, and its method of use, in which self-ionized plasma (SIP) sputtering and inductively coupled plasma (ICP) sputtering are promoted, either together or alternately, in the same or different chambers. Also, bottom coverage may be thinned or eliminated by ICP resputtering in one chamber and SIP in another. SIP is promoted by a small magnetron having poles of unequal magnetic strength and a high power applied to the target during sputtering. ICP is provided by one or more RF coils which inductively couple RF energy into a plasma. The combined SIP-ICP layers can act as a liner or barrier or seed or nucleation layer for hole. In addition, an RF coil may be sputtered to provide protective material during ICP resputtering. In another chamber an array of auxiliary magnets positioned along sidewalls of a magnetron sputter reactor on a side towards the wafer from the target.
    Type: Application
    Filed: July 30, 2008
    Publication date: September 17, 2009
    Applicant: APPLIED MATERIALS, INC.
    Inventors: Peijun DING, Rong TAO, Zheng XU, Daniel C. LUBBEN, Suraj RENGARAJAN, Michael A. MILLER, Arvind SUNDARRAJAN, Xianmin TANG, John C. FORSTER, Jianming FU, Roderick C. MOSELY, Fusen CHEN, Praburam GOPALRAJA
  • Patent number: 7547644
    Abstract: In a first aspect, a method is provided that includes (1) forming a first barrier layer over the sidewalls and bottom of a via using atomic layer deposition within an atomic layer deposition (ALD) chamber; (2) removing at least a portion of the first barrier layer from the bottom of the via by sputter etching; and (3) depositing a second barrier layer on the sidewalls and bottom of the via within the ALD chamber. Numerous other embodiments are provided, as are systems, methods and computer program products in accordance with these and other aspects.
    Type: Grant
    Filed: November 1, 2005
    Date of Patent: June 16, 2009
    Assignee: Applied Materials, Inc.
    Inventors: Fusen Chen, Ling Chen, Walter Benjamin Glenn, Praburam Gopalraja, Jianming Fu
  • Publication number: 20090087982
    Abstract: Embodiments of the invention provide processes for selectively forming a ruthenium-containing film on a copper surface over exposed dielectric surfaces. Thereafter, a copper bulk layer may be deposited on the ruthenium-containing film. In one embodiment, a method for forming layers on a substrate is provided which includes positioning a substrate within a processing chamber, wherein the substrate contains a copper-containing surface and a dielectric surface, exposing the substrate to a ruthenium precursor to selectively form a ruthenium-containing film over the copper-containing surface while leaving exposed the dielectric surface, and depositing a copper bulk layer over the ruthenium-containing film.
    Type: Application
    Filed: September 29, 2008
    Publication date: April 2, 2009
    Inventors: RONGJUN WANG, Hua Chung, Jick M. Yu, Praburam Gopalraja
  • Patent number: 7504006
    Abstract: A DC magnetron sputter reactor for sputtering deposition materials such as tantalum and tantalum nitride, for example, and its method of use, in which self-ionized plasma (SIP) sputtering and capacitively coupled plasma (CCP) sputtering are promoted, either together or alternately, in the same chamber. Also, bottom coverage may be thinned or eliminated by inductively-coupled plasma (ICP) resputtering. SIP is promoted by a small magnetron having poles of unequal magnetic strength and a high power applied to the target during sputtering. CCP is provided by a pedestal electrode which capacitively couples RF energy into a plasma. The CCP plasma is preferably enhanced by a magnetic field generated by electromagnetic coils surrounding the pedestal which act to confine the CCP plasma and increase its density.
    Type: Grant
    Filed: July 31, 2003
    Date of Patent: March 17, 2009
    Assignee: Applied Materials, Inc.
    Inventors: Praburam Gopalraja, Jianming Fu, Xianmin Tang, John C. Forster, Umesh Kelkar
  • Publication number: 20090053888
    Abstract: A method of depositing a duffusion barrier layer with overlying conductive layer or fill which lowers resistivity of a semiconductor device interconnect. The lower resistivity is achieved by inducing the formation of alpha tantalum within a tantalum-comprising barrier layer.
    Type: Application
    Filed: October 20, 2008
    Publication date: February 26, 2009
    Inventors: Peijun Ding, Zheng Xu, Hong Zhang, Xianmin Tang, Praburam Gopalraja, Suraj Rengarajan, John C. Forster, Jianming Fu, Tony Chiang, Gongda Yao, Fusen E. Chen, Barry L. Chin, Gene Y. Kohara
  • Publication number: 20080237029
    Abstract: A method and resultant produce of forming barrier layer based on ruthenium tantalum in a via or other vertical interconnect structure through a dielectric layer in a multi-level metallization. The RuTa layer in a RuTa/RuTaN bilayer, which may form discontinuous islands, is actively oxidized, preferably in an oxygen plasma, to thereby bridge the gaps between the islands. Alternatively, ruthenium tantalum oxide is reactive sputtered onto the RuTaN or directly onto the underlying dielectric by plasma sputtering a RuTa target in the presence of oxygen.
    Type: Application
    Filed: March 26, 2007
    Publication date: October 2, 2008
    Applicant: Applied Materials, Inc.
    Inventors: Xianmin TANG, Hua Chung, Rongjun Wang, Praburam Gopalraja, Jick M. Yu, Jenn Yue Wang
  • Publication number: 20080190760
    Abstract: An integrated copper deposition process, particularly useful for forming a copper seed layer in a narrow via prior to electrochemical plating of copper, including at least one cycle of sputter deposition of copper followed by sputter etching of the deposited copper, preferably performed in a same sputter chamber. The deposition is performed under conditions promoting high copper ionization fractions and strong wafer biasing to draw the copper ions into the via. The etching may be done with argon ions, preferably inductively excited by an RF coil around the chamber, or by copper ions, which may be formed with high target power and intense magnetron or by use of the RF coil. Two or more cycles of deposition/etch may be performed. A final flash deposition may be performed with high copper ionization and low wafer biasing.
    Type: Application
    Filed: August 14, 2007
    Publication date: August 14, 2008
    Applicant: Applied Materials, Inc.
    Inventors: XIANMIN TANG, Arvind Sundarrajan, Daniel Lubben, Qian Luo, Tza-Jing Gung, Anantha Subramani, Hua Chung, Xinyu Fu, Rongjun Wang, Yong Cao, Jick Yu, John Forster, Praburam Gopalraja
  • Publication number: 20080142359
    Abstract: A DC magnetron sputter reactor for sputtering deposition materials such as tantalum and tantalum nitride, for example, and its method of use, in which self-ionized plasma (SIP) sputtering and capacitively coupled plasma (CCP) sputtering are promoted, either together or alternately, in the same chamber. Also, bottom coverage may be thinned or eliminated by inductively-coupled plasma (ICP) resputtering. SIP is promoted by a small magnetron having poles of unequal magnetic strength and a high power applied to the target during sputtering. CCP is provided by a pedestal electrode which capacitively couples RF energy into a plasma. The CCP plasma is preferably enhanced by a magnetic field generated by electromagnetic coils surrounding the pedestal which act to confine the CCP plasma and increase its density.
    Type: Application
    Filed: October 31, 2007
    Publication date: June 19, 2008
    Applicant: APPLIED MATERIALS, INC.
    Inventors: Praburam GOPALRAJA, Jianming FU, Xianmin TANG, John C. FORSTER, Umesh KELKAR
  • Publication number: 20080110747
    Abstract: A magnetron sputter reactor for sputtering deposition materials such as tantalum, tantalum nitride and copper, for example, and its method of use, in which self-ionized plasma (SIP) sputtering and inductively coupled plasma (ICP) sputtering are promoted, either together or alternately, in the same or different chambers. Also, bottom coverage may be thinned or eliminated by ICP resputtering in one chamber and SIP in another. SIP is promoted by a small magnetron having poles of unequal magnetic strength and a high power applied to the target during sputtering. ICP is provided by one or more RF coils which inductively couple RF energy into a plasma. The combined SIP-ICP layers can act as a liner or barrier or seed or nucleation layer for hole. In addition, an RF coil may be sputtered to provide protective material during ICP resputtering. In another chamber an array of auxiliary magnets positioned along sidewalls of a magnetron sputter reactor on a side towards the wafer from the target.
    Type: Application
    Filed: October 31, 2007
    Publication date: May 15, 2008
    Applicant: APPLIED MATERIALS, INC.
    Inventors: Peijun DING, Rong TAO, Zheng XU, Daniel LUBBEN, Suraj RENGARAJAN, Michael MILLER, Arvind SUNDARRAJAN, Xianmin TANG, John FORSTER, Jianming FU, Roderick MOSELY, Fusen CHEN, Praburam GOPALRAJA
  • Publication number: 20080083610
    Abstract: A plasma sputter chamber and process for sputtering ruthenium and tantalum at low pressure or with self-sustained sputtering (SSS). The source magnetron is strongly unbalanced and of sufficient size to project the unbalanced magnetic field toward the wafer to increase the ionization probability. Sputter etch uniformity is increased by the use of an auxiliary magnet system rotating with the source magnetron but placed towards the center of rotation. It may be a larger, nearly balanced auxiliary magnetron with an outer polarity matching that of the source magnetron or an array of magnets of that polarity. An integrated process includes a directional deposition of the refractory metal and its nitride, a sputter etch, and a flash deposition.
    Type: Application
    Filed: March 22, 2007
    Publication date: April 10, 2008
    Applicant: Applied Materials, Inc.
    Inventors: Xianmin Tang, Hua Chung, Rongjun Wang, Tza-Jing Gung, Praburam Gopalraja, Jick Yu, Hong Yang
  • Patent number: 7335282
    Abstract: A sputtering process and magnetron especially advantageous for low-pressure plasma sputtering or sustained self-sputtering, in which the magnetron has a reduced area but full target coverage. The magnetron includes an outer pole face surrounding an inner pole face with a gap therebetween. The outer pole of the magnetron of the invention is smaller than that of a circular magnetron similarly extending from the center to the periphery of the target and has a substantially larger total magnetic intensity. Thereby, sputtering at low pressure and high ionization fraction is enabled.
    Type: Grant
    Filed: September 13, 2004
    Date of Patent: February 26, 2008
    Inventors: Jianming Fu, Praburam Gopalraja, Fusen Chen, John Forster
  • Publication number: 20070241458
    Abstract: A metal/metal nitride barrier layer for semiconductor device applications. The barrier layer is particularly useful in contact vias where high conductivity of the via is important, and a lower resistivity barrier layer provides improved overall via conductivity.
    Type: Application
    Filed: May 30, 2007
    Publication date: October 18, 2007
    Inventors: Peijun Ding, Zheng Xu, Hong Zhang, Xianmin Tang, Praburam Gopalraja, Suraj Rengarajan, John Forster, Jianming Fu, Tony Chiang, Gongda Yao, Fusen Chen, Barry Chin, Gene Kohara
  • Publication number: 20070209925
    Abstract: A substrate processing method practiced in a plasma sputter reactor including an RF coil and two or more coaxial electromagnets, at least two of which are wound at different radii. After a barrier layer, for example, of tantalum is sputter deposited into a via hole, the RF coil is powered to cause argon sputter etching of the barrier layer and the current to the electromagnets are adjusted to steer the argon ions, for example to eliminate sidewall asymmetry. For example, the two electromagnets are powered with unequal currents of opposite polarities or a third electromagnet wrapped at a different height is powered. In one embodiment, the steering straightens the trajectories near the wafer edge. In another embodiment, the etching is divided into two steps in which the steering inclines the trajectories at opposite angles. The invention may also be applied to other materials, such as copper.
    Type: Application
    Filed: March 9, 2006
    Publication date: September 13, 2007
    Applicant: Applied Materials, Inc.
    Inventors: Xianmin Tang, Praburam Gopalraja, Jenn Wang, Jick Yu
  • Patent number: 7253109
    Abstract: We have discovered a method of providing a thin, approximately from about 2 ? to about 100 ? thick TaN seed layer, which can be used to induce the formation of alpha tantalum when tantalum is deposited over the TaN seed layer. Further, the TaN seed layer exhibits low resistivity, in the range of 30 ??cm and can be used as a low resistivity barrier layer in the absence of an alpha tantalum layer. In one embodiment of the method, a TaN film is altered on its surface to form the TaN seed layer. In another embodiment of the method, a Ta film is altered on its surface to form the TaN seed layer.
    Type: Grant
    Filed: February 28, 2005
    Date of Patent: August 7, 2007
    Assignee: Applied Materials, Inc.
    Inventors: Peijun Ding, Zheng Xu, Hong Zhang, Xianmin Tang, Praburam Gopalraja, Suraj Rengarajan, John C. Forster, Jianming Fu, Tony Chiang, Gongda Yao, Fusen E. Chen, Barry L. Chin, Gene Y. Kohara
  • Publication number: 20070117397
    Abstract: A plasma cleaning method particularly useful for removing photoresist and oxide residue from a porous low-k dielectric with a high carbon content prior to sputter deposition. A remote plasma source produces a plasma primarily of hydrogen radicals. The hydrogen pressure may be kept relatively low, for example, at 30 milliTorr. Optionally, helium may be added to the processing gas with the hydrogen partial pressure held below 150 milliTorr. Superior results are obtained with 70% helium in 400 milliTorr of hydrogen and helium. Preferably, an ion filter, such as a magnetic filter, removes hydrogen and other ions from the output of the remote plasma source and a supply tube from the remote plasma source includes a removable dielectric liner in combination with dielectric showerhead and manifold liner.
    Type: Application
    Filed: January 17, 2006
    Publication date: May 24, 2007
    Applicant: Applied Materials, Inc.
    Inventors: Xinyu Fu, John Forster, Jick Yu, Ajay Bhatnagar, Praburam Gopalraja
  • Publication number: 20070095654
    Abstract: A multi-step sputtering process in plasma sputter reactor having target and magnetron operable in two modes, for example, in a substrate sputter etch and a substrate sputter deposition. The target has an annular vault facing the wafer to be sputter coated. Various types of magnetic means positioned around the vault create a magnetic field supporting a plasma extending over a large volume of the vault. An integrated copper via filling process with the inventive reactor or other reactor includes a first step of highly ionized sputter deposition of copper, which can optionally be used to remove the barrier layer at the bottom of the via, a second step of more neutral, lower-energy sputter deposition of copper to complete the seed layer, and a third step of electroplating copper into the hole to complete the metallization. The first two steps can be also used with barrier metals.
    Type: Application
    Filed: December 11, 2006
    Publication date: May 3, 2007
    Applicant: Applied Materials, Inc.
    Inventors: Praburam Gopalraja, Jianming Fu, Fusen Chen, Girish Dixit, Zheng Xu, Wei Wang, Ashok Sinha
  • Publication number: 20070062452
    Abstract: A coil has an integral fastener portion to facilitate fastening the coil to a shield wall to reduce generation of particulates.
    Type: Application
    Filed: November 20, 2006
    Publication date: March 22, 2007
    Inventors: Ian Pancham, Michael Rosenstein, Leif DeLaurentis, Allen Lau, Praburam Gopalraja, James Gogh
  • Publication number: 20070059502
    Abstract: A fabrication method and a product for the deposition of a conductive barrier or other liner layer in a vertical electrical interconnect structure. One embodiment includes within a a hole through a dielectric layer a barrier layer of RuTaN, an adhesion layer of RuTa, and a copper seed layer forming a liner for electroplating of copper. The ruthenium content is preferably greater than 50 at % and more preferably at least 80 at % but less than 95 at %. The barrier and adhesion layers may both be sputter deposited. Other platinum-group elements substitute for the ruthenium and other refractory metals substitute for the tantalum. Aluminum alloying into RuTa when annealed presents a moisture barrier. Copper contacts include different alloying fractions of RuTa to shift the work function to the doping type.
    Type: Application
    Filed: August 29, 2006
    Publication date: March 15, 2007
    Applicant: Applied Materials, Inc.
    Inventors: Rongjun Wang, Hua Chung, Xianmin Tang, Jenn Wang, Wei Wang, Yoichiro Tanaka, Jick Yu, Praburam Gopalraja
  • Publication number: 20070051622
    Abstract: A magnetron sputter reactor including an ion beam source producing a linear beam that strikes the wafer center at an angle of less than 35°. The linear beam extends across the wafer perpendicular to the beam but has a much short dimension along the beam propagation axis while the wafer is being rotated. The ion source may be an anode layer source having a plasma loop between an inner magnetic pole and a surrounding outer magnetic pole with anode overlying the loop with a closed-loop aperture. The beams from the opposed sides of the loop are steered together by making the outer pole stronger than the inner pole. The aperture width may be varied to control the emission intensity.
    Type: Application
    Filed: September 2, 2005
    Publication date: March 8, 2007
    Inventors: Xianmin Tang, Anantha Subramani, Praburam Gopalraja, Jianming Fu, Jick Yu