Patents by Inventor Atul Gupta

Atul Gupta 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: 7727866
    Abstract: The manufacture of solar cells is simplified and cost reduced through by performing successive ion implants, without an intervening thermal cycle. In addition to reducing process time, the use of chained ion implantations may also improve the performance of the solar cell. In another embodiment, two different species are successively implanted without breaking vacuum. In another embodiment, the substrate is implanted, then flipped such that it can be and implanted on both sides before being annealed. In yet another embodiment, one or more different masks are applied and successive implantations are performed without breaking the vacuum condition, thereby reducing the process time.
    Type: Grant
    Filed: March 4, 2009
    Date of Patent: June 1, 2010
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Nicholas Bateman, Atul Gupta, Paul Sullivan, Paul Murphy
  • Publication number: 20100090131
    Abstract: A method includes directing an ion beam at a plurality of differing incident angles with respect to a target surface of a substrate by tilting the substrate as the ion beam is distributed across the target surface to implant ions into a plurality of portions of the substrate, wherein each one of the plurality of differing incident angles is associated with a different one of the plurality of portions, measuring angle sensitive data from each of the plurality of portions of to the substrate, and determining an angle misalignment between the target surface and the ion beam incident on the target surface from the angle sensitive data.
    Type: Application
    Filed: December 17, 2009
    Publication date: April 15, 2010
    Applicant: VARIAN SEMICONDUCTOR EQUIPMENT ASSOCIATES, INC.
    Inventors: Atul GUPTA, Joseph C. Olson
  • Patent number: 7683347
    Abstract: A technique for improving ion implantation throughput and dose uniformity is disclosed. In one exemplary embodiment, a method for improving ion implantation throughput and dose uniformity may comprise measuring an ion beam density distribution in an ion beam. The method may also comprise calculating an ion dose distribution across a predetermined region of a workpiece that results from a scan velocity profile, wherein the scan velocity profile comprises a first component and a second component that control a relative movement between the ion beam and the workpiece in a first direction and a second direction respectively, and wherein the ion dose distribution is based at least in part on the ion beam density distribution. The method may further comprise adjusting at least one of the first component and the second component of the scan velocity profile to achieve a desired ion dose distribution in the predetermined region of the workpiece.
    Type: Grant
    Filed: September 29, 2006
    Date of Patent: March 23, 2010
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Atul Gupta, Anthony Renau, Donna Smatlak, Joseph C. Olson
  • Publication number: 20100048018
    Abstract: A method of fabricating metal interconnects with reduced electromigration includes depositing metal interconnects on a substrate comprising electronic devices. A layer is deposited on the metal interconnects. The layer is doped with at least one dopant having a dopant concentration that increases an electromigration resistance of the metal atoms.
    Type: Application
    Filed: August 25, 2008
    Publication date: February 25, 2010
    Applicant: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Atul Gupta, Heyun Yin, Vikram Singh
  • Patent number: 7655931
    Abstract: Techniques improving the performance and extending the lifetime of an ion source with gas mixing are disclosed. In one particular exemplary embodiment, the techniques may be realized as a method for improving performance and extending lifetime of an ion source in an ion implanter. The method may comprise introducing a predetermined amount of dopant gas into an ion source chamber. The dopant gas may comprise a dopant species. The method may also comprise introducing a predetermined amount of diluent gas into the ion source chamber. The diluent gas may dilute the dopant gas to improve the performance and extend the lifetime of the ion source. The diluent gas may further comprise a co-species that is the same as the dopant species.
    Type: Grant
    Filed: March 29, 2007
    Date of Patent: February 2, 2010
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventor: Atul Gupta
  • Patent number: 7642529
    Abstract: A method includes directing an ion beam at a plurality of differing incident angles with respect to a target surface of a substrate to implant ions into a plurality of portions of the substrate, wherein each one of the plurality of differing incident angles is associated with a different one of the plurality of portions, measuring angle sensitive data from each of the plurality of portions of the substrate, and determining an angle misalignment between the target surface and the ion beam incident on the target surface from the angle sensitive data. A method of determining a substrate miscut is also provided.
    Type: Grant
    Filed: September 29, 2006
    Date of Patent: January 5, 2010
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Atul Gupta, Joseph C. Olson
  • Publication number: 20090317937
    Abstract: A improved, lower cost method of producing solar cells utilizing selective emitter design is disclosed. The contact regions are created on the substrate without the use of lithography or masks. The method utilizes ion implantation technology, and the relatively low accuracy requirements of the contact regions to reduce the process steps needed to produce a solar cell. In some embodiments, the current of the ion beam is selectively modified to create the highly doped contact regions. In other embodiments, the ion beam is focused, either through the use of an aperture or via adjustments to the beam line components to create the necessary doping profile. In still other embodiments, the wafer scan rate is modified to create the desired ion implantation pattern.
    Type: Application
    Filed: August 28, 2008
    Publication date: December 24, 2009
    Inventors: Atul Gupta, Nicholas Bateman, Paul Murphy, Anthony Renau, Charles Carlson
  • Publication number: 20090227097
    Abstract: A method of tailoring the dopant profile of a substrate by utilizing two different dopants, each having a different diffusivity is disclosed. The substrate may be, for example, a solar cell. By introducing two different dopants, such as by ion implantation, furnace diffusion, or paste, it is possible to create the desired dopant profile. In addition, the dopants may be introduced simultaneously, partially simultaneously, or sequentially. Dopant pairs preferably consist of one lighter species and one heavier species, where the lighter species has a greater diffusivity. For example, dopant pairs such as boron and gallium, boron and indium, phosphorus and arsenic, and phosphorus and antimony, can be utilized.
    Type: Application
    Filed: March 4, 2009
    Publication date: September 10, 2009
    Inventors: Nicholas Bateman, Atul Gupta, Christopher Hatem, Deepak Ramappa
  • Publication number: 20090227095
    Abstract: Methods of counterdoping a solar cell, particularly an IBC solar cell are disclosed. One surface of a solar cell may require portions to be n-doped, while other portions are p-doped. Traditionally, a plurality of lithography and doping steps are required to achieve this desired configuration. In contrast, one lithography step can be eliminated by the use of a blanket doping of one conductivity and a mask patterned counterdoping process of the opposite conductivity. The areas dosed during the masked patterned doping receive a sufficient dose so as to completely reverse the effect of the blanket doping and achieve a conductivity that is opposite the blanket doping. In another embodiment, the counterdoping is performed by means of a direct patterning technique, thereby eliminating the remaining lithography step. Various methods of direct counterdoping processes are disclosed.
    Type: Application
    Filed: March 4, 2009
    Publication date: September 10, 2009
    Inventors: Nicholas Bateman, Atul Gupta, Paul Sullivan
  • Publication number: 20090227061
    Abstract: Methods of controlling the diffusion of a dopant in a solar cell are disclosed. A second species is used in conjunction with the dopant to modify the diffusion region. For example, phosphorus and boron both diffuse by pairing with interstitial silicon atoms. Thus, by controlling the creation and location of these interstitials, the diffusion rate of the dopant can be controlled. In one embodiment, a heavier element, such as germanium, argon or silicon, is used to create interstitials. Because of the presence of these heavier elements, the dopant diffuses deeper into the substrate. In another embodiment, carbon is implanted. Carbon reduces the number of interstitials, and thus can be used to limit the diffusion of the dopant. In another embodiment, a lighter element, such as helium is used to amorphize the substrate. The crystalline-amorphous interface created limits diffusion of the dopant into the substrate.
    Type: Application
    Filed: March 4, 2009
    Publication date: September 10, 2009
    Inventors: Nicholas Bateman, Atul Gupta, Christopher Hatem, George Papasouliotis, Helen Maynard
  • Publication number: 20090227094
    Abstract: The manufacture of solar cells is simplified and cost reduced through by performing successive ion implants, without an intervening thermal cycle. In addition to reducing process time, the use of chained ion implantations may also improve the performance of the solar cell. In another embodiment, two different species are successively implanted without breaking vacuum. In another embodiment, the substrate is implanted, then flipped such that it can be and implanted on both sides before being annealed. In yet another embodiment, one or more different masks are applied and successive implantations are performed without breaking the vacuum condition, thereby reducing the process time.
    Type: Application
    Filed: March 4, 2009
    Publication date: September 10, 2009
    Inventors: Nicholas Bateman, Atul Gupta, Paul Sullivan, Paul Murphy
  • Publication number: 20090206273
    Abstract: An apparatus and a method for detecting particle beam characteristics are disclosed. In one embodiment, the apparatus may have a body including a first end and second end and at least one detector between the first and second ends. The apparatus may have a transparent state where a portion of the particles entering the apparatus may pass through the apparatus. The apparatus may also have a minimum transparency state where substantially all of the particles entering the apparatus may be prevented from passing through the apparatus and detected. Different transparency state may be achieved by rotating the apparatus or the detector contained therein. With the apparatus, it is possible to detect the beam properties such as the beam intensity, angle, parallelism, and a distribution of the particles in a particle beam.
    Type: Application
    Filed: February 14, 2008
    Publication date: August 20, 2009
    Applicant: VARIAN SEMICONDUCTOR EQUIPMENT ASSOCIATES, INC.
    Inventors: Joseph C. Olson, Atul Gupta
  • Patent number: 7561983
    Abstract: A technique for improving ion implantation based on ion beam angle-related information is disclosed. In one particular exemplary embodiment, the technique may be realized as a method for improving ion implantation. The method may comprise obtaining angle-related information associated with an ion beam. The method may also comprise calculating, based on the angle-related information, an ion beam angle distribution over a wafer for one or more potential scanning modes. The method may further comprise selecting a desired scanning mode from the one or more potential scanning modes based on an evaluation of performance metric caused by the ion beam angle distribution.
    Type: Grant
    Filed: September 29, 2006
    Date of Patent: July 14, 2009
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Atul Gupta, Jonathan Gerald England
  • Publication number: 20090166566
    Abstract: The present invention comprises a method for high tilt angle implantation, with angular precision not previously achievable. An ion beam, having a width and height dimension, is made up of a number of individual beamlets. These beamlets typically display a higher degree of parallelism in one of these two dimensions. Thus, to minimize angular error, the workpiece is tilted about an axis substantially perpendicular to the dimension having the higher degree of parallelism. The workpiece is then implanted at a high tilt angle and rotated about a line orthogonal to the surface of the workpiece. This process can be repeated until the high tilt implantation has been performed in all required regions.
    Type: Application
    Filed: December 28, 2007
    Publication date: July 2, 2009
    Inventors: Atul Gupta, Joseph C. Olson
  • Patent number: 7542979
    Abstract: The present invention includes an apparatus, method and system for loading data into a database. The invention includes a spreadsheet dataset, having data in the form of one or more records, a control file containing a set of rules, each rule having a condition and a spreadsheet loader. The spreadsheet dataset and the control file are inputs to the spreadsheet loader. Each rule in the control file is evaluated for each record to determine if the condition is true for the record, and the records are parsed if the condition is true. The spreadsheet loader sends the parsed data to the database. The invention includes a user interface to facilitate creation of the control file.
    Type: Grant
    Filed: October 1, 2004
    Date of Patent: June 2, 2009
    Assignee: Schlumberger Technology Corporation
    Inventors: Atul Gupta, Amar Singh
  • Patent number: 7524743
    Abstract: A method of doping includes depositing a layer of dopant material on nonplanar and planar features of a substrate. Inert ions are generated from an inert feed gas. The inert ions are extracted towards the substrate where they physically knock the dopant material into both the planar and nonplanar features of the substrate.
    Type: Grant
    Filed: October 13, 2005
    Date of Patent: April 28, 2009
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Atul Gupta, Vikram Singh, Timothy Miller, Edmund Jacques Winder
  • Patent number: 7525103
    Abstract: A technique for improving uniformity of a ribbon beam is disclosed. In one particular exemplary embodiment, an apparatus may comprise a first corrector-bar assembly and a second corrector-bar assembly, wherein the second corrector-bar assembly is located at a predetermined distance from the first corrector-bar assembly. Each of a first plurality of coils in the first corrector-bar assembly may be individually excited to deflect at least one beamlet in the ribbon beam, thereby causing the beamlets to arrive at the second corrector-bar assembly in a desired spatial spread. Each of a second plurality of coils in the second corrector-bar assembly may be individually excited to further deflect one or more beamlets in the ribbon beam, thereby causing the beamlets to exit the second corrector-bar assembly at desired angles.
    Type: Grant
    Filed: September 29, 2006
    Date of Patent: April 28, 2009
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Kenneth H. Purser, Atul Gupta
  • Publication number: 20090104761
    Abstract: A method of plasma doping includes generating a plasma comprising dopant ions proximate to a platen supporting a substrate in a plasma chamber. The platen is biased with a bias voltage waveform having a negative potential that attracts ions in the plasma to the substrate for plasma doping. At least one sensor measuring data related to charging conditions favorable for forming an electrical discharge is monitored. At least one plasma process parameter is modified in response to the measured data, thereby reducing a probability of forming an electrical discharge.
    Type: Application
    Filed: October 19, 2007
    Publication date: April 23, 2009
    Applicant: VARIAN SEMICONDUCTOR EQUIPMENT ASSOCIATES, INC.
    Inventors: Yongbae Jeon, Vikram Singh, Timothy Miller, Ziwei Fang, Steven Walther, Atul Gupta
  • Publication number: 20090104719
    Abstract: A method of in-situ monitoring of a plasma doping process includes generating a plasma comprising dopant ions in a chamber proximate to a platen supporting a substrate. A platen is biased with a bias voltage waveform having a negative potential that attracts ions in the plasma to the substrate for plasma doping. A dose of ions attracted to the substrate is measured. At least one sensor measurement is performed to determine the condition of the plasma chamber. In addition, at least one plasma process parameter is modified in response to the measured dose and in response to the at least one sensor measurement.
    Type: Application
    Filed: October 23, 2007
    Publication date: April 23, 2009
    Applicant: VARIAN SEMICONDUCTOR EQUIPMENT ASSOCIATES, INC.
    Inventors: Atul Gupta, Timothy Miller, Harold M. Persing, Daniel Distaso, Vikram Singh
  • Patent number: 7453070
    Abstract: A beam density measurement system includes a shield, a beam sensor, and an actuator. The beam sensor is positioned downstream from the shield in a direction of travel of a beam. The beam sensor is configured to sense an intensity of the beam, and the beam sensor has a long dimension and a short dimension. The actuator translates the shield relative to the beam sensor, wherein the shield blocks at least a portion of the beam from the beam sensor as the shield is translated relative to the beam sensor, and wherein measured values of the intensity associated with changes in a position of the shield relative to the beam sensor are representative of a beam density distribution of the beam in a first direction defined by the long dimension of the beam sensor.
    Type: Grant
    Filed: June 29, 2006
    Date of Patent: November 18, 2008
    Assignee: Varian Semiconductor Associates, Inc.
    Inventors: Atul Gupta, Joseph C. Olson, Gregg A. Norris