Patents by Inventor Steven Kasapi

Steven Kasapi 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).

  • Publication number: 20060108997
    Abstract: A system, apparatus, and method for analyzing photon emission data to discriminate between photons emitted by transistors and photons emitted by background sources. The analysis involves spatial and/or temporal correlation of photon emissions. After correlation, the analysis may further involve obtaining a likelihood that the correlated photons were emitted by a transistor. After correlation, the analysis may also further involve assigning a weight to individual photon emissions as a function of the correlation. The weight, in some instances, reflecting a likelihood that the photons were emitted by a transistor. The analysis may further involve automatically identifying transistors in a photon emission image.
    Type: Application
    Filed: December 8, 2005
    Publication date: May 25, 2006
    Applicant: Credence Systems Corporation
    Inventors: Romain Desplats, Patricia Le Coupanec, William Lo, Philippe Perdu, Steven Kasapi
  • Patent number: 7049593
    Abstract: A single-photon detector includes a superconductor strip biased near its critical current. The superconductor strip provides a discernible output signal upon absorption of a single incident photon. In one example, the superconductor is a strip of NbN (niobium nitride). In another example, the superconductor strip meanders to increase its probability of receiving a photon from a light source. The single-photon detector is suitable for a variety of applications including free-space and satellite communications, quantum communications, quantum cryptography, weak luminescence, and semiconductor device testing.
    Type: Grant
    Filed: October 19, 2004
    Date of Patent: May 23, 2006
    Assignees: Credence Systems Corporation, University of Rochester
    Inventors: Roman Sobolewski, Grigory N. Gol'tsman, Alexey D. Semenov, Oleg V. Okunev, Kenneth R. Wilsher, Steven A. Kasapi
  • Publication number: 20060103378
    Abstract: Systems and methods consistent with principles of the present invention allow contactless measuring of various kinds of electrical activity within an integrated circuit. The invention can be used for high-bandwidth, at speed testing of various devices on a wafer during the various stages of device processing, or on packaged parts at the end of the manufacturing cycle. Power is applied to the test circuit using conventional mechanical probes or other means, such as CW laser light applied to a photoreceiver provided on the test circuit. The electrical test signal is introduced into the test circuit by stimulating the circuit using a contactless method, such as by directing the output of one or more modelocked lasers onto high-speed receivers on the circuit, or by using a high-speed pulsed diode laser.
    Type: Application
    Filed: November 12, 2004
    Publication date: May 18, 2006
    Inventors: Nader Pakdaman, Steven Kasapi, Itzik Goldberger
  • Patent number: 7042563
    Abstract: A method and system of testing integrated circuits (IC) via optical coupling. The optical system includes an optical fiber, fixture and focusing element. In addition, channels are provided in the fixture mounted on the integrated circuit to accommodate the optical system. The fixture acts as a heat sink. As such, one or more photosensitive elements/targets on the integrated circuit are probed using light that is brought to a focus on each target site. The light causes latching of data into the integrated circuit (which is operating under influence of a test program) and formation of a test pattern output from the integrated circuit that is used to confirm proper functioning of the IC.
    Type: Grant
    Filed: January 24, 2005
    Date of Patent: May 9, 2006
    Assignee: Credence Systems Corporation
    Inventors: Kenneth R. Wilsher, Steven Kasapi
  • Patent number: 7038442
    Abstract: A system, apparatus, and method for analyzing photon emission data to discriminate between photons emitted by transistors and photons emitted by background sources. The analysis involves spatial and/or temporal correlation of photon emissions. After correlation, the analysis may further involve obtaining a likelihood that the correlated photons were emitted by a transistor. After correlation, the analysis may also further involve assigning a weight to individual photon emissions as a function of the correlation. The weight, in some instances, reflecting a likelihood that the photons were emitted by a transistor. The analysis may further involve automatically identifying transistors in a photon emission image.
    Type: Grant
    Filed: January 20, 2005
    Date of Patent: May 2, 2006
    Assignee: Credence Systems Corporation
    Inventors: Romain Desplats, Patricia Le Coupanec, William K. Lo, Philippe Perdu, Steven Kasapi
  • Patent number: 7012537
    Abstract: A beacon circuit enabling study of active elements in an integrated circuit is disclosed. The beacon circuit may be integral to a DUT to be tested. The DUT is stimulated by a conventional ATE, so that its active devices are operating. The signal from the active device is sent to the beacon circuit which, in response to the signal, emits light having intensity that is proportional to the value of the signal. In one example, the beacon circuit is constructed as a voltage to current converter having its input connected to the node of interest and its output connected to a current to light converter. In one example, the current to light converter is implemented as a current mirror circuit. One beneficial implementation disclosed is the use of the beacon circuit for the study of voltage supply disturbances.
    Type: Grant
    Filed: May 14, 2004
    Date of Patent: March 14, 2006
    Assignee: Credence Systems Corporation
    Inventors: Gary Leonard Woods, Steven Kasapi
  • Publication number: 20060031036
    Abstract: Systems and methods consistent with principles of the present invention allow contactless measurements of voltage characteristics of dynamic electrical signals in integrated circuits. The invention utilizes a signal analysis circuit, such as a voltage comparator, disposed with the circuit under test, which is optically coupled with the external timing measurement equipment. The signal analysis circuit changes its state depending on the characteristics of the measured electrical signal applied thereto. The changes in the condition of the signal analysis circuit are sensed by the external timing measurement equipment provided outside the circuit under test. To this end, the signal analysis circuit is optically coupled with the external measurement equipment registering specific changes in the condition of the signal analysis circuit.
    Type: Application
    Filed: September 30, 2005
    Publication date: February 9, 2006
    Applicant: Credence Systems Corporation
    Inventor: Steven Kasapi
  • Patent number: 6985219
    Abstract: A method and system of testing integrated circuits (IC) via optical coupling. The optical system includes an optical fiber, fixture and focussing element. In addition, channels are provided in the fixture mounted on the integrated circuit to accommodate the optical system. The fixture acts as a heat sink. As such, one or more photosensitive elements/targets on the integrated circuit are probed using light that is brought to a focus on each target site. The light causes latching of data into the integrated circuit (which is operating under influence of a test program) and formation of a test pattern output from the integrated circuit that is used to confirm proper functioning of the IC.
    Type: Grant
    Filed: December 21, 2000
    Date of Patent: January 10, 2006
    Assignee: Credence Systems Corporation
    Inventors: Kenneth R. Wilsher, Steven A Kasapi
  • Patent number: 6976234
    Abstract: Systems and methods consistent with principles of the present invention allow contactless measurements of voltage characteristics of dynamic electrical signals in integrated circuits. The invention utilizes a signal analysis circuit, such as a voltage comparator, disposed with the circuit under test, which is optically coupled with the external timing measurement equipment. The signal analysis circuit changes its state depending on the characteristics of the measured electrical signal applied thereto. The changes in the condition of the signal analysis circuit are sensed by the external timing measurement equipment provided outside the circuit under test. To this end, the signal analysis circuit is optically coupled with the external measurement equipment registering specific changes in the condition of the signal analysis circuit.
    Type: Grant
    Filed: January 13, 2003
    Date of Patent: December 13, 2005
    Assignee: Credence Systems Corporation
    Inventor: Steven Kasapi
  • Patent number: 6961672
    Abstract: A universal diagnostic platform (UDP) is described which incorporates several measurement modules for testing a device under test (DUT). Users can switch between measurement modules without removing the DUT. The UDP employs a common fixturing and software system for all the modules.
    Type: Grant
    Filed: March 5, 2003
    Date of Patent: November 1, 2005
    Assignee: Credence Systems Coporation
    Inventor: Steven Kasapi
  • Patent number: 6956365
    Abstract: A system and method for calibration of a commercial semiconductor test system (tester). The system receives a synchronization signal from the tester and detects light emission from a device under test (DUT). The system then compares the timing and characteristics of the light emission to the synchronization signal to obtain a delay timing and signal change caused by intermediate elements of the tester. The delay timing and signal change are used to calibrate the various channels of the tester. Also described are various designs for DUT's to obtained enhanced accuracy of the delay timing. Further, a system and method are described for reconstruction of a test signal and study of the effects of intermediate elements of the tester on the shape of the test signal.
    Type: Grant
    Filed: April 8, 2003
    Date of Patent: October 18, 2005
    Assignee: Credence Systems Corporation
    Inventors: Israel Niv, Steven Kasapi
  • Publication number: 20050174248
    Abstract: A beacon circuit enabling study of active elements in an integrated circuit is disclosed. The beacon circuit may be integral to a DUT to be tested. The DUT is stimulated by a conventional ATE, so that its active devices are operating. The signal from the active device is sent to the beacon circuit which, in response to the signal, emits light having intensity that is proportional to the value of the signal. In one example, the beacon circuit is constructed as a voltage to current converter having its input connected to the node of interest and its output connected to a current to light converter. In one example, the current to light converter is implemented as a current mirror circuit. One beneficial implementation disclosed is the use of the beacon circuit for the study of voltage supply disturbances.
    Type: Application
    Filed: May 14, 2004
    Publication date: August 11, 2005
    Inventors: Gary Woods, Steven Kasapi
  • Publication number: 20050146321
    Abstract: A system, apparatus, and method for analyzing photon emission data to discriminate between photons emitted by transistors and photons emitted by background sources. The analysis involves spatial and/or temporal correlation of photon emissions. After correlation, the analysis may further involve obtaining a likelihood that the correlated photons were emitted by a transistor. After correlation, the analysis may also further involve assigning a weight to individual photon emissions as a function of the correlation. The weight, in some instances, reflecting a likelihood that the photons were emitted by a transistor. The analysis may further involve automatically identifying transistors in a photon emission image.
    Type: Application
    Filed: January 20, 2005
    Publication date: July 7, 2005
    Applicant: Credence Systems Corporation
    Inventors: Romain Desplats, Patricia Le Coupanec, William Lo, Philippe Perdu, Steven Kasapi
  • Publication number: 20050128471
    Abstract: A method and system of testing integrated circuits (IC) via optical coupling. The optical system includes an optical fiber, fixture and focussing element. In addition, channels are provided in the fixture mounted on the integrated circuit to accommodate the optical system. The fixture acts as a heat sink. As such, one or more photosensitive elements/targets on the integrated circuit are probed using light that is brought to a focus on each target site. The light causes latching of data into the integrated circuit (which is operating under influence of a test program) and formation of a test pattern output from the integrated circuit that is used to confirm proper functioning of the IC.
    Type: Application
    Filed: January 24, 2005
    Publication date: June 16, 2005
    Applicant: Credence Systems Corporation
    Inventors: Kenneth Wilsher, Steven Kasapi
  • Publication number: 20050110893
    Abstract: A system and method for automatically and accurately determining the exact location of a knife-edge, such as an edge of an optical shutter, so that it can be controlled automatically. In one aspect the system comprises a mechanized shutter coupled to a shutter controller that can automatically control the shutter's location and movement. According to one implementation of the shutter controller the system takes a first image at a first shutter position. The shutter is then moved a predetermined about and a second image is taken. Then, the pixels of each image are added in the direction perpendicular to the movement of the shutter, so as to provide two one-dimension functions. A linear difference of the functions is then taken, so as to obtain a one-dimensional linear difference function. A peak in the linear difference function is then identified as the location of the shutter.
    Type: Application
    Filed: November 20, 2003
    Publication date: May 26, 2005
    Inventors: Steven Kasapi, Amit Nabarro, Ofir Baharav
  • Patent number: 6891363
    Abstract: A system, apparatus, and method for analyzing photon emission data to discriminate between photons emitted by transistors and photons emitted by background sources. The analysis involves spatial and/or temporal correlation of photon emissions. After correlation, the analysis may further involve obtaining a likelihood that the correlated photons were emitted by a transistor. After correlation, the analysis may also further involve assigning a weight to individual photon emissions as a function of the correlation. The weight, in some instances, reflecting a likelihood that the photons were emitted by a transistor. The analysis may further involve automatically identifying transistors in a photon emission image.
    Type: Grant
    Filed: September 3, 2002
    Date of Patent: May 10, 2005
    Assignee: Credence Systems Corporation
    Inventors: Romain Desplats, Patricia Le Coupanec, William K. Lo, Philippe Perdu, Steven Kasapi
  • Publication number: 20050051726
    Abstract: A single-photon detector includes a superconductor strip biased near its critical current. The superconductor strip provides a discernible output signal upon absorption of a single incident photon. In one example, the superconductor is a strip of NbN (niobium nitride). In another example, the superconductor strip meanders to increase its probability of receiving a photon from a light source. The single-photon detector is suitable for a variety of applications including free-space and satellite communications, quantum communications, quantum cryptography, weak luminescence, and semiconductor device testing.
    Type: Application
    Filed: October 19, 2004
    Publication date: March 10, 2005
    Applicant: Credence Systems Corporation
    Inventors: Roman Sobolewski, Grigory Gol'tsman, Alexey Semenov, Oleg Okunev, Kenneth Wilsher, Steven Kasapi
  • Patent number: 6859031
    Abstract: Systems and methods consistent with principles of the present invention allow contactless measuring of various kinds of electrical activity within an integrated circuit. The invention can be used for high-bandwidth, at speed testing of various devices on a wafer during the various stages of device processing, or on packaged parts at the end of the manufacturing cycle. Power is applied to the test circuit using conventional mechanical probes or other means, such as CW laser light applied to a photoreceiver provided on the test circuit. The electrical test signal is introduced into the test circuit by stimulating the circuit using a contactless method, such as by directing the output of one or more modelocked lasers onto high-speed receivers on the circuit, or by using a high-speed pulsed diode laser.
    Type: Grant
    Filed: August 26, 2002
    Date of Patent: February 22, 2005
    Assignee: Credence Systems Corporation
    Inventors: Nader Pakdaman, Steven Kasapi, Itzik Goldberger
  • Publication number: 20050002028
    Abstract: A system for temporal and spectral resolved detection of photon emission from an integrated circuit is disclosed. A DUT is stimulated by a conventional ATE, so that its active devices emit light. The signal from the ATE is also sent to the system's computer as a synchronization signal. The light emitted from the switching devices is passed through a wavelength filter. Selected bands of wavelengths are then passed to respective detector(s) and the detector(s) response with respect to the time correlated ATE stimulus is studied.
    Type: Application
    Filed: July 2, 2003
    Publication date: January 6, 2005
    Inventors: Steven Kasapi, Gary Woods, John Field
  • Patent number: 6836131
    Abstract: A combination cooling plate and micro-spray cooling system beneficial for use in testers of electrically stimulated integrated circuit chips is disclosed. The system includes a transparent heat spreader and micro-spray heads disposed about the heat spreader. The spray heads spray cooling liquid onto a periphery of said heat spreader so as to remove heat from the chip. Alternatively, and micro-spray heads are provided inside the cooling plate holder so as to spray cooling liquid inside the interior of the holder so that the holder is cooled. The holder is in physical contact with the heat spreader, so that as the holder is cooled by the spray, heat is removed from the heat spreader, and thereby from the chip.
    Type: Grant
    Filed: March 4, 2003
    Date of Patent: December 28, 2004
    Assignee: Credence Systems Corp.
    Inventors: Tahir Cader, Nathan Stoddard, Donald Tilton, Nader Pakdaman, Steven Kasapi