Having Emissivity Compensating Or Specified Radiating Surface Patents (Class 374/126)
  • Patent number: 5860740
    Abstract: A thermometer is provided with a ROM, in which a program for controlling a CPU and plural predetermined emissivity data are memorized, and is further provided with a RAM having plural registers, in which plural emissivity data are entered and memorized. One of these memorized emissivity data is selected and used for measuring a temperature of an object. The selected emissivity data and an output of a temperature sensor are amplified by an amplifier, and are supplied to an A/D convertor to obtain digital data. The CPU processes the digital data to obtain temperature data, and displays the obtained temperature data. With this structure of the thermometer, emissivity data can be set with a simple operation.
    Type: Grant
    Filed: March 16, 1995
    Date of Patent: January 19, 1999
    Assignee: Casio Computer Co., Ltd.
    Inventor: Mikako Fujima
  • Patent number: 5830277
    Abstract: System and method for determining thermal characteristics, such as temperature, temperature uniformity and emissivity, during thermal processing using shielded pyrometry. The surface of a semiconductor substrate is shielded to prevent interference from extrinsic light from radiant heating sources and to form an effective black-body cavity. An optical sensor is positioned to sense emitted light in the cavity for pyrometry. The effective emissivity of the cavity approaches unity independent of the semiconductor substrate material which simplifies temperature calculation. The shield may be used to prevent undesired backside deposition. Multiple sensors may be used to detect temperature differences across the substrate and in response heaters may be adjusted to enhance temperature uniformity.
    Type: Grant
    Filed: May 26, 1995
    Date of Patent: November 3, 1998
    Assignee: Mattson Technology, Inc.
    Inventors: Kristian E. Johnsgard, James McDiarmid
  • Patent number: 5823681
    Abstract: An emissivity compensating non-contact system for measuring the temperature of a semiconductor wafer. The system includes a semiconductor wafer emissivity compensation station for measuring the reflectivity of the wafer at discrete wavelengths to yield wafer emissivity in specific wavelength bands. The system further includes a measurement probe which is optically coupled to a semiconductor process chamber. The probe senses wafer self emission using one or more optical detectors and a light modulator. A background temperature determining mechanism independently senses the temperature of a source of background radiation. Finally, a mechanism calculates the temperature of the semiconductor wafer based on the reflectivity, self-emission and background temperature.
    Type: Grant
    Filed: February 29, 1996
    Date of Patent: October 20, 1998
    Assignee: C.I. Systems (Israel) Ltd.
    Inventors: Dario Cabib, Robert A. Buckwald, Michael E. Adel
  • Patent number: 5802099
    Abstract: The heat energy in a reactor used to process substrates is controlled to allow a more accurate measurement of the substrate temperature. The method of substrate temperature measurement is applicable to any reactor geometry and any type of heat source. Further, the method does not affect the process and so the performance of the reactor is unaffected when the substrate temperature measurement method is utilized. At a first predetermined time t1 during the process cycle, power to the heat source is turned off. At a second predetermined time t2, i.e., at the end of a time interval after the power is turned off, the heat energy from the reactor is measured for a predefined time interval, i.e., from second predetermined time t2 to a third predetermined time t3. After the measurement, i.e., at a fourth predetermined time t4, the power to the heat source is turned-on again and the process cycle continues. The time window over which the power is turned-off, i.e.
    Type: Grant
    Filed: August 26, 1996
    Date of Patent: September 1, 1998
    Assignee: Moore Epitaxial, Inc.
    Inventors: William J. Curran, Gary M. Moore
  • Patent number: 5785426
    Abstract: Pyrometer with a probe beam superimposed on its field-of-view for furnace temperature measurements. The pyrometer includes a heterodyne millimeter/sub-millimeter-wave or microwave receiver including a millimeter/sub-millimeter-wave or microwave source for probing. The receiver is adapted to receive radiation from a surface whose temperature is to be measured. The radiation includes a surface emission portion and a surface reflection portion which includes the probe beam energy reflected from the surface. The surface emission portion is related to the surface temperature and the surface reflection portion is related to the emissivity of the surface. The simultaneous measurement of surface emissivity serves as a real time calibration of the temperature measurement. In an alternative embodiment, a translatable base plate and a visible laser beam allow slow mapping out of interference patterns and obtaining peak values therefor.
    Type: Grant
    Filed: October 6, 1995
    Date of Patent: July 28, 1998
    Assignees: Massachusetts Institute of Technology, Battelle Memorial Institute
    Inventors: Paul P. Woskov, Daniel R. Cohn, Charles H. Titus, Jeffrey E. Surma
  • Patent number: 5764684
    Abstract: The output stability of an infrared thermocouple is improved by filtering the radiation received by the infrared thermocouple to pass only short wavelengths. The stability is further increased by providing a second infrared thermocouple having its input filtered to pass long wavelengths. The two outputs are combined to obtain an output signal which is substantially independent of emissivity. The linear range of an infrared detector through which its output closely follows that of a linear thermocouple is increased by a calibration method in which an initial offset is provided to a readout device. Calibration of the infrared detector is completed using an adjustable potentiometer. By providing removable apertures, the temperature range through which an infrared thermocouple may be used is extended. Elongated targets are efficiently viewed by an infrared thermocouple having an elongated thermopile flake and an imaging lens.
    Type: Grant
    Filed: April 4, 1995
    Date of Patent: June 9, 1998
    Assignee: Exergen Corporation
    Inventor: Francesco Pompei
  • Patent number: 5755511
    Abstract: A method of correcting a temperature probe reading in a thermal processing chamber for heating a substrate, including the steps of heating the substrate to a process temperature; using a first, a second and a third probe to measure the temperature of the substrate, the first and third probes having a first effective reflectivity and the second probe having a second effective reflectivity, the first probe producing a first temperature indication, the second probe producing a second temperature indication and the third probe producing a third temperature indication, and wherein the first and second effective reflectivities are different; and from the first and second temperature indications, deriving a corrected temperature reading for the first probe, wherein the corrected temperature reading is a more accurate indicator of an actual temperature of the substrate than an uncorrected readings produced by both the first and second probes.
    Type: Grant
    Filed: May 1, 1996
    Date of Patent: May 26, 1998
    Assignee: Applied Materials, Inc.
    Inventors: Bruce W. Peuse, Gary E. Miner, Mark Yam
  • Patent number: 5743644
    Abstract: To provide a temperature measuring apparatus making it possible to automatically calculate a correction multiplier by assuming the data measured by a contact-type thermometer as a true value and always accurately measure temperature by the noncontact method in accordance with the correction multiplier. The temperature measuring apparatus comprises noncontact- and contact-type thermometers for measuring the temperature of a temperature measurement object, arithmetic means for calculating a correction multiplier for correcting an error of data measured by the noncontact-type thermometer in accordance with the data measured by the noncontact-type thermometer and a value measured by the contact-type thermometer and moreover calculating a correction value by correcting the data measured by the noncontact-type thermometer in accordance with the correction multiplier, and display means for displaying the measured value and the correction value.
    Type: Grant
    Filed: August 29, 1995
    Date of Patent: April 28, 1998
    Assignee: Anritsu Meter Co., Ltd.
    Inventors: Seishiro Kobayashi, Akiyoshi Nabei, Shuichi Takashina, Takashi Fujishiro
  • Patent number: 5738440
    Abstract: A system and method of measurement of emissivity and radiance of a wafer in a rapid thermal processing chamber enables determination of wafer temperature and control of temperature of the wafer. Mirrors enclose the chamber and reflect radiation from lamps within the chamber to heat the workpiece of interest. One or more viewing ports are provided in one of the mirrors to allow for the egress of radiant energy emitted by the wafer. The wavelength of the exiting radiation is selected by an optical filter having a passband which passes radiation at wavelengths emitted by the wafer while excluding radiation emitted by heating lamps. A chopper having surface regions differing in their reflectivity and transmissivity is positioned along an optical path of radiation propagating through the one or more ports, this resulting in a pulsation of detected radiation.
    Type: Grant
    Filed: December 23, 1994
    Date of Patent: April 14, 1998
    Assignee: International Business Machines Corp.
    Inventors: James Anthony O'Neill, Jyothi Singh
  • Patent number: 5727017
    Abstract: A method and apparatus for measuring the emission coefficient of a semiconductor material for light of wavelength .lambda. having photon energy less than the semiconductor bandgap energy is introduced. The reflection coefficient for the light of wavelength .lambda. is measured while the semiconductor material is being irradiated with sufficient light having photon energy greater than the bandgap energy that the semiconductor material transmits little light of wavelength .lambda., and the emission coefficient is calculated from the measured reflection coefficient. The temperature of the semiconductor material can be calculated from the emission coefficient and the measured intensity of the thermally emitted radiation of wavelength .lambda..
    Type: Grant
    Filed: April 10, 1996
    Date of Patent: March 10, 1998
    Assignee: AST Electronik, GmbH
    Inventors: Michael Maurer, Wilfried Lerch, Alexander Gschwandtner
  • Patent number: 5713666
    Abstract: A method and apparatus for measuring thermal properties of electronic components (25) encapsulated in packaging is described. The method can be used to measure a junction temperature T.sub.j of the electronic component (25), without removing the package (30), and during operation of the electronic component (25) by a power supply.
    Type: Grant
    Filed: August 30, 1995
    Date of Patent: February 3, 1998
    Assignee: Seelink Technology
    Inventors: Kusuma S. Seelin, Srikanth N. Seelin
  • Patent number: 5709473
    Abstract: A temperature sensor comprising: a wave guide with a cylindrical wall; a material of low emissivity included at the cylindrical wall for generating black body radiation into the wave guide, wherein at least a portion of the generated black body radiation is carried through the wave guide; a first sensor receiving the generated black body radiation and providing a first output signal indicative of a first magnitude of a first bandwidth of the generated black body radiation; and a second sensor receiving the generated black body radiation and providing a second output signal indicative of a second magnitude of a second bandwidth of the generated black body radiation, wherein a difference between the first and second output signals is a linearized indication of temperature of at least a portion of the wave guide.
    Type: Grant
    Filed: May 13, 1996
    Date of Patent: January 20, 1998
    Assignee: General Motors Corporation
    Inventors: Michel Farid Sultan, Michael James O'Rourke
  • Patent number: 5704712
    Abstract: A method for remotely measuring the temperature of a target maintained at a first relatively low temperature while at the same time the target is heated by thermal radiation from a source spaced from the target and maintained at a second relatively high temperature which employs a two wavelength radiometer and a computer. First and second wavelengths are selected for use. The second wavelength is shorter than the first wavelength, both source and target exhibiting appreciable radiation at the first wavelength, the source emitting appreciable radiation while the target emits essentially no radiation at the second wavelength. The radiation of the source at the first wavelength and at the second wavelength are measured. These two source radiation measurements are stored in the computer. The radiation of the target at the first wavelength and at the second wavelength are measured. These two target radiation measurements are stored in the computer.
    Type: Grant
    Filed: January 18, 1996
    Date of Patent: January 6, 1998
    Assignee: Quantum Logic Corporation
    Inventor: Alexander Stein
  • Patent number: 5696703
    Abstract: A method of monitoring the temperature of a target (4), the method comprising:a) sensing radiation emitted by the target (4) at at least two different wavelengths;b) determining a temperature value from the sensed radiation in accordance with a first predetermined algorithm;c) repeating steps a) and b) a number of times to generate a set of temperature values;d) selecting a target temperature from the set of temperature values in accordance with a second predetermined algorithm; and,e) generating an output signal defining the target temperature obtained in step d).
    Type: Grant
    Filed: May 23, 1995
    Date of Patent: December 9, 1997
    Assignee: Land Instruments International Ltd.
    Inventor: Roy Barber
  • Patent number: 5690430
    Abstract: Method and apparatus for measuring the surface temperature/emissivity of coated steel strip during a coating (e.g., galvannealing) process. The apparatus includes first and second radiation sensors each having a response exponentially related to the reciprocal of absolute temperature when viewing a blackbody source, and each positioned to receive focused radiation from the surface to be measured to provide first and second signals indicative of the radiation received by the sensor, respectively. To provide the focused radiation, the apparatus includes an optical system for gathering thermal radiation emitted by the surface to be measured and focusing it onto the sensors after a first common filter and second individual filters of differing wavelengths such that the first sensor is responsive to shorter wavelengths, the second sensor is responsive to longer wavelengths, and both sensors view the same area simultaneously.
    Type: Grant
    Filed: March 15, 1996
    Date of Patent: November 25, 1997
    Assignee: Bethlehem Steel Corporation
    Inventor: Ralph G. Rudolph
  • Patent number: 5688051
    Abstract: A radiation pyrometer assembly and method for sensing the temperature of an elongate body, such as metal strip, moving longitudinally in the direction of its length includes a spray gun which deposits a narrow stripe of black paint of a uniform emissivity, upon one surface of the strip as it moves towards a temperature sensing station. The sensing station includes a calibration radiation pyrometer arranged to view the black stripe once the temperature of the stripe has reached the temperature of the strip. The accuracy of the apparatus may be improved by the provision of a process control radiation pyrometer directed to the opposite, unpainted surface of the strip the combined readings from the two pyrometers allow the correction of otherwise unpredictable errors in the temperature of the strip.
    Type: Grant
    Filed: April 12, 1995
    Date of Patent: November 18, 1997
    Assignee: Davy McKee (Poole) Limited
    Inventors: Roger Ernest King, Graham Peter Spurge
  • Patent number: 5683181
    Abstract: An embodiment of an apparatus for enhancing remote infrared (IR) temperature measurement of a low-emissivity sample includes a flexible membrane of a high-emissivity material for converting thermal energy from the sample into IR energy, an enclosed shroud, an IR camera, a light source, and at least one fan. The membrane is coupled to the enclosed shroud at one end of the shroud for supporting the membrane. The shroud includes at least four walls and an end wall opposite the membrane to define an interior space. The end wall includes an imaging window formed therethrough for accommodating the IR camera, which is provided for detecting IR energy radiated from the membrane. The light source is disposed in the interior space and mounted to the shroud for illuminating the membrane.
    Type: Grant
    Filed: May 12, 1995
    Date of Patent: November 4, 1997
    Assignee: Thermal Wave Imaging, Inc.
    Inventor: Steven M. Shepard
  • Patent number: 5660472
    Abstract: A method of correcting a temperature probe reading in a thermal processing chamber for heating a substrate, including the steps of heating the substrate to a process temperature; using a first probe and a second probe to measure the temperature of the substrate, the first probe having a first effective reflectivity and the second chamber having a second effective reflectivity, the first probe producing a first temperature indication and the second probe producing a second temperature indication, and wherein the first and second effective reflectivities are different; and from the first and second temperature indications, deriving a corrected temperature reading for the first probe, wherein the corrected temperature reading is a more accurate indicator of an actual temperature of the substrate than are uncorrected readings produced by both the first and second probes.
    Type: Grant
    Filed: December 19, 1994
    Date of Patent: August 26, 1997
    Assignee: Applied Materials, Inc.
    Inventors: Bruce W. Peuse, Gary E. Miner, Mark Yam
  • Patent number: 5640015
    Abstract: A pyrometer for measuring the electromagnetic radiation emitted by an object comprises a first detector to which the radiation is delivered through an optical system as well as a second detector to which the radiation emanating from a reference element is delivered through the same optical system. The temperature of the reference element is monitored and a rotary optical modulator periodically enables and disables the delivery of radiation to the detectors. The output signals from the two detectors are processed to determine the difference therebetween. The sensed temperature of the reference element is taken into account as a part of determining the difference between the two detector output signals. In this way it is possible for the characteristic radiation of the optical system largely to be suppressed. The optical modulator comprises a semi-circular disk having a polyethylene terephthalate substrate coated on each side with metal. The disk is rotated through 180.degree.
    Type: Grant
    Filed: October 23, 1995
    Date of Patent: June 17, 1997
    Assignee: Raytek Sensorik GmbH
    Inventors: Ulrich Kienitz, Thomas Heinke, Uwe Klonowski, Peter Preuss, Holger Sandring, Volker Schmidt
  • Patent number: 5628564
    Abstract: A method and apparatus for optical pyrometry in a Rapid Thermal Processing (RTP) System, whereby the radiation used to heat the object to be processed in the RTP system is in part specularly reflected from specularly reflecting surfaces and is incident on the object with a particular angular distribution, and the thermal radiation from the object is measured at an angles different from the angle where the incident radiation specularly reflected from the surface of the object is a maximum.
    Type: Grant
    Filed: March 28, 1995
    Date of Patent: May 13, 1997
    Assignee: AST Elekronik GmbH
    Inventors: Zsolt Nenyei, Andreas Tillmann, Heinrich Walk
  • Patent number: 5624190
    Abstract: A method of measuring the surface temperature of an object. The method includes performing ellipsometric measurements on the object in order to determine at least first and second photon energies (E.sub.1, E.sub.2) for an electromagnetic beam at which measurements are respectively substantially independent of temperature and dependent on temperature. The method further includes creating and directing to the object, an electromagnetic incident beam including at least the first and second photon energies (E.sub.1, E.sub.2). The change in polarization at the first photon energy (E.sub.1) is measured and the thickness of the layer of material is determined on the basis of this measurement. The surface temperature of the object can then be determined on the basis of the measured change in polarization at the second photon energy (E.sub.2) of the beam, while taking account of the thickness of the layer of material.
    Type: Grant
    Filed: July 26, 1995
    Date of Patent: April 29, 1997
    Assignee: Ecole Centrale de Lyon
    Inventors: Jacques Joseph, Yao-Zhi Hu, Eugene Irene
  • Patent number: 5624590
    Abstract: In an apparatus and process for heating, e.g., a semiconductor wafer within a processing chamber, the wafer is exposed to a flux of electromagnetic radiation from lamps energized by alternating electric current. The surface temperature of the wafer is measured, and responsively, the radiation flux is controlled. The temperature measurement procedure includes collecting radiation propagating away from the wafer in a first probe, collecting radiation propagating away from the wafer and radiation from the lamps in a second probe, and detecting radiation collected in the respective probes. This procedure further involves deconvolving the multiphase ac component of the signal received from each probe, determining the linear functional relationship of the first probe signal as a function of the second probe signal resulting from time-variations of the energizing current, and using this linear functional relationship along with the signal data according to a mathematical expression to infer the temperature.
    Type: Grant
    Filed: April 7, 1995
    Date of Patent: April 29, 1997
    Assignee: Lucent Technologies, Inc.
    Inventor: Anthony T. Fiory
  • Patent number: 5601366
    Abstract: A method for obtaining real-time emissivity and temperature values of a semiconductor wafer in a processing system having at least one lamp (preferably a plurality of lamps arranged in a plurality of zones so as to provide multizone temperature and emissivity values for the semiconductor wafer) arranged in at least one zone, the method using a reference wafer having a known reflectivity and the method comprising the steps of: measuring pyrometry signals for the reference wafer (step 202) and generating calibration curves from the measurements; measuring pyrometry signals for the semiconductor wafer; and obtaining the temperature and emissivity values (step 222) from the calibration curves and the measured pyrometry signals (step 220) for the semiconductor wafer.
    Type: Grant
    Filed: October 25, 1994
    Date of Patent: February 11, 1997
    Assignee: Texas Instruments Incorporated
    Inventor: Ajit P. Paranjpe
  • Patent number: 5573339
    Abstract: Radiometer with a probe beam superimposed on its field-of-view for furnace temperature measurements. The radiometer includes a heterodyne millimeter/submillimeter-wave receiver including a millimeter/submillimeter-wave source for probing. The receiver is adapted to receive radiation from a surface whose temperature is to be measured. The radiation includes a surface emission portion and a surface reflection portion which includes the probe beam energy reflected from the surface. The surface emission portion is related to the surface temperature and the surface reflection portion is related to the emissivity of the surface. The simultaneous measurement of surface emissivity serves as a real time calibration of the temperature measurement.
    Type: Grant
    Filed: January 14, 1994
    Date of Patent: November 12, 1996
    Assignees: Electro-Pyrolysis, Inc., Massachusetts Institute of Technology, Battelle Memorial Institute
    Inventors: Paul P. Woskov, Daniel R. Cohn, Charles H. Titus, J. Kenneth Wittle, Jeffrey E. Surma
  • Patent number: 5564830
    Abstract: The invention describes a procedure and an arrangement for measurement of temperature and thickness of layer during a deposition or coating process. As coating or depositing processes known technologies of semi-conductor manufacturing arrangements, plasma devices, ion devices, and other dry-etching arrangements may be used. The invention can also be applied to the manufacture of optical coatings. As a consequence of interference of the thermal radiation of the substrate at the growing layer, the emissivity .epsilon. changes continuously during coating or depositing, therefore, a pyrometric measurement of temperature may not be applied. This basic problem is solved by the invention, which uses a reflectometer, which determines the reflectivity R of the wafer. According to the law of conservation of energy .epsilon.=1-R so that with said reflectometer the actual emissivity of the whole (multi-layer) system may be determined. The measurement of temperature then is effected by means of a determination equation.
    Type: Grant
    Filed: January 18, 1994
    Date of Patent: October 15, 1996
    Assignee: Fraunhofer Gesellschaft zur Forderung der angewandten Forschung e.V.
    Inventors: Friedrich Bobel, Norbert Bauer
  • Patent number: 5508934
    Abstract: A computer controlled system for real-time control of semiconductor wafer fabrication process uses a multi-point, real-time, non-invasive, in-situ pyrometry-based temperature sensor with emissivity compensation to produce semiconductor wafer reflectance, transmittance, and radiant heat energy measurements. The temperature values that the sensor determines are true temperatures for various points on the wafer. The process control computer stores surface roughness values for the semiconductor wafer being examined. The surface roughness values are produced by surface roughness sensor that makes non-invasive and in-situ measurements. The surface roughness sensor performs roughness measurements of the semiconductor wafer based on coherent reflectance and scatter reflectance of the wafer. Based on surface roughness measurements, the process control computer can use the real-time, in-situ measurements of the multi-point pyrometry-based sensor to obtain real-time measurements of time wafer temperature distribution.
    Type: Grant
    Filed: May 4, 1994
    Date of Patent: April 16, 1996
    Assignee: Texas Instruments Incorporated
    Inventors: Mehrdad M. Moslehi, Habib N. Najm
  • Patent number: 5501637
    Abstract: A direct, noncontact temperature sensor includes an ellipsometer (104-106) to determine absorptance for layered structures and a pyrometer (102) to determine emissive power and combines the two measurements to determine temperature.
    Type: Grant
    Filed: September 20, 1994
    Date of Patent: March 26, 1996
    Assignee: Texas Instruments Incorporated
    Inventors: Walter M. Duncan, Francis G. Celii, Steven A. Henck, Ajit P. Paranjpe, Douglas L. Mahlum, Larry A. Taylor
  • Patent number: 5460451
    Abstract: A pyrometer for measuring thermal radiation and emissivity for both diffusely and specularly reflecting surfaces of an object which includes, a thermal radiation detector and an optical system connected to the detector for concentrating thermal radiation originating from an object surface area on the detector, an emissivity meter connected to the optical system, the meter further comprising a radiation source supplying measuring radiation and a measuring radiation detector, an optical integrator adjacent to the object surface area arranged in the radiation path of the measuring radiation between the radiation source and the measuring radiation detector, wherein the radiation source extends through an aperture of the optical integrator and diffusely irradiates the object surface, and a shield connected to the optical integrator for preventing measuring radiation from irradiating the object surface area directly, is described.
    Type: Grant
    Filed: December 27, 1993
    Date of Patent: October 24, 1995
    Assignee: U.S. Philips Corporation
    Inventor: Sipke Wadman
  • Patent number: 5443315
    Abstract: A multi-zone emissivity correction system and method that may be used in a multi-zone illuminator of a RTP-AVP system. The multi-zone illuminator comprises a plurality of lamps arranged in zones. A dummy lamp is also provided for each zone. A first plurality of sensors monitor the wafer and a second plurality of sensors monitor dummy lamp radiance. For each zone, an emissivity factor is determined based on the first and second pluralities of sensors. An effective black body radiance is also determined for each zone based on a wafer radiance factor for each zone and the emissivity factors.
    Type: Grant
    Filed: December 16, 1993
    Date of Patent: August 22, 1995
    Assignee: Texas Instruments Incorporated
    Inventors: Yong J. Lee, Mehrdad M. Moslehi
  • Patent number: 5444815
    Abstract: A multi-zone lamp interference correction system and method for accurate pyrometry-based multi-point wafer temperature measurement in a multi-zone rapid thermal processing system comprises a plurality of lamps arranged in zones. A dummy lamp is also provided for each zone. Each lamp heating zone and its associated dummy lamp are connected to a controllable power supply. The radiance from a particular zone in the wafer combined with the lamp interference associated with the zone is measured using a first plurality of sensors. The lamp radiation from the plurality of dummy lamps are monitored using a second plurality of sensors. For each zone, a lamp interference component is removed from the wafer temperature sensor signal. The lamp interference components are based on geometry factors and the lamp radiance signals.
    Type: Grant
    Filed: December 16, 1993
    Date of Patent: August 22, 1995
    Assignee: Texas Instruments Incorporated
    Inventors: Yong J. Lee, Mehrdad M. Moslehi
  • Patent number: 5442727
    Abstract: In a process for heating, e.g., a semiconductor wafer within a processing chamber, the wafer is exposed to a flux of electromagnetic radiation from lamps energized by alternating electric current. The surface temperature of the wafer is measured, and responsively, the radiation flux is controlled. The temperature measurement procedure includes collecting radiation propagating away from the wafer in a first light-pipe probe, collecting radiation propagating toward the wafer in a second light-pipe probe, and detecting radiation collected in the respective probes. This procedure further involves determining, in the signal received from each probe, a magnitude of a time-varying component resulting from time-variations of the energizing current, and combining at least these magnitudes according to a mathematical expression from which the temperature can be inferred. At least some of the radiation collected by the second probe is collected after reflection from a diffusely reflecting surface.
    Type: Grant
    Filed: April 14, 1994
    Date of Patent: August 15, 1995
    Assignee: AT&T Corp.
    Inventor: Anthony T. Fiory
  • Patent number: 5436443
    Abstract: A radiation pyrometer for measuring the true temperature of a body is provided by detecting and measuring thermal radiation from the body based on the principle that the effects of angular emission I.sub.1 and reflection I.sub.2 on the polarization states p and s of radiation are complementary such that upon detecting the combined partial polarization state componentsI.sub.p =I.sub.1p +I.sub.2pI.sub.s =I.sub.1s +I.sub.2sand adjusting the intensity of the variable radiation source of the reflected radiation I.sub.2 until the combined partial radiation components I.sub.p and I.sub.s are equal, the effects of emissivity as well as diffusivity of the surface of the body are eliminated, thus obviating the need for any post processing of brightness temperature data.
    Type: Grant
    Filed: July 6, 1994
    Date of Patent: July 25, 1995
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Ali A. Abtahi
  • Patent number: 5381229
    Abstract: An optical interferometer comprises a multi-mode sapphire fiber as a high temperature sensor. One end of the sapphire fiber is coupled to a silica fiber and, in turn, to the sapphire fiber. The sapphire fiber sensor produces reference and sensor reflections that produce optical fringes at the output of a detector coupled to the silica optical fiber via an opto-coupler. The optical fringes are related to displacements of the sensor which, in turn, can provide an indirect measurement of pressure, strain or temperature of the surface.
    Type: Grant
    Filed: August 31, 1992
    Date of Patent: January 10, 1995
    Assignee: Center for Innovative Technology
    Inventors: Kent Murphy, Ashish Vengsarkar, Shari Feth, Richard Claus, Sridhar Gollapudi, Anbo Wang
  • Patent number: 5364186
    Abstract: A blackbody high temperature probe is formed by thermally fusing a coating of composite ceramic material on the tip of a high temperature lightpipe or fiber. The ceramic coating replaces conventional sputtered metallic thin films to form a blackbody optical cavity. The ingredients of the composite ceramic material include a mixture of refractory metal oxides forming the bulk of the material, various pigments and/or refractory metal powders, and binding agents. A firing process is used to thermally fuse the coating onto the lightpipe. Embodiments of the firing process include using a flame or furnace technique, or alternatively using various flame- or plasma- spraying techniques.
    Type: Grant
    Filed: April 28, 1992
    Date of Patent: November 15, 1994
    Assignee: Luxtron Corporation
    Inventors: Zhihai Wang, Bruce Adams
  • Patent number: 5326173
    Abstract: An apparatus and method for remotely measuring emissivity and hence temperature of a surface of an object. The apparatus includes a detector having a radiation receptor for measuring infra-red radiation, an integrating cavity surrounding the receptor for receiving radiation from a surface facing the cavity and delivering the radiation to the receptor, at least two sources of infra-red containing radiation (e.g. light from an incandescent lamp) within the integrating cavity positioned to produce separate beams of the radiation which strike the surface at different angles suitable for reflection to the receptor, and a processor for determining the temperature of the surface from the radiation measured by the detecting means. The use of at least two mutually angled radiation beams compensates for surface anisotropy of the surface whose temperature is to be measured.
    Type: Grant
    Filed: January 11, 1993
    Date of Patent: July 5, 1994
    Assignee: Alcan International Limited
    Inventors: Dan Evans, Matthew J. Fairlie, Karam Kang, Serge Zouikin
  • Patent number: 5326172
    Abstract: A method and apparatus for detecting the temperature of gray and non-gray bodies in the presence of interfering radiation. A gray body has a constant emissivity less than 1 and a non-gray body has an emissivity which varies with wavelength. The emissivity and reflectivity of the surface is determined over a range of wavelengths. Spectra are also measured of the extraneous interference radiation source and the surface of the object to be measured in the presence of the extraneous interference radiation source. An auxiliary radiation source is used to determine the reflectivity of the surface and also the emissivity. The measured spectrum of the surfaces in the presence of the extraneous interference radiation source is set equal to the emissivity of the surface multiplied by a Planck function containing a temperature term T plus the surface reflectivity multiplied by the spectrum of the extraneous interference radiation source. The equation is then solved for T to determine the temperature of the surface.
    Type: Grant
    Filed: December 14, 1992
    Date of Patent: July 5, 1994
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Daniel L. P. Ng
  • Patent number: 5308161
    Abstract: Pyrometer apparatus measures the temperature of a semiconductor wafer which when heated by radiation from a bank of lamps emits thermal radiation which includes radiation contained in a selected spectral band. The apparatus includes a reaction chamber supporting the wafer and disposed above the bank of lamps. A hollow envelope reflecting incident radiation and thermal radiation from the wafer surrounds and is spaced from the chamber and the bank of lamps. A portion of the reflected radiation and the thermal radiation passes upwardly through a first opening. A source of said incident radiation disposed adjacent a second opening produces radiation within said spectral band which enters said envelope and is reflected inside the envelope to illuminate a selected spot on the wafer hemispherically. The spot reflects a portion of the incident radiation upwardly through the first opening.
    Type: Grant
    Filed: February 11, 1993
    Date of Patent: May 3, 1994
    Assignee: Quantum Logic Corporation
    Inventor: Alexander Stein
  • Patent number: 5305417
    Abstract: In a RTP reactor where wafer temperature is measured by a pyrometer assembly (32), a pyrometer assembly (50) is further provided to measure the temperature of the quartz window (30) that is situated between the wafer pyrometer assembly (32) and the wafer (16) that is being processed. During the calibration procedure (100, 120) where a thermocouple wafer is used, the measurements from the wafer pyrometer assembly (32) and the window pyrometer assembly (50) are calibrated, and pyrometer measurements and thermocouple measurements are collected and compiled into calibration tables. During actual RTP reactor operation, the data from the calibration tables and current wafer and window pyrometer measurements are used to compute corrected wafer temperature(s). The corrected wafer temperature(s) is/are then used to control the intensities of the heating lamps according to the wafer processing heating schedule.
    Type: Grant
    Filed: March 26, 1993
    Date of Patent: April 19, 1994
    Assignee: Texas Instruments Incorporated
    Inventors: Habib N. Najm, Mehrdad M. Moslehi, Somnath Banerjee, Lino A. Velo
  • Patent number: 5305416
    Abstract: In a process for heating, e.g., a semiconductor wafer within a processing chamber, the wafer is exposed to a flux of electromagnetic radiation from lamps energized by alternating electric current. The surface temperature of the wafer is measured, and responsively, the radiation flux is controlled. The temperature measurement procedure includes collecting radiation propagating away from the wafer in a first light-pipe probe, collecting radiation propagating toward the wafer in a second light-pipe probe and detecting radiation collected in the respective probes. This procedure further involves determining, in the signal received from each probe, a magnitude of a time-varying component resulting from time-variations of the energizing current, and combining at least these magnitude according to a mathematical expression from which the temperature can be inferred. At least some of the radiation collected by the second probe is collected after reflection from a diffusely reflecting surface.
    Type: Grant
    Filed: April 2, 1993
    Date of Patent: April 19, 1994
    Assignee: AT&T Bell Laboratories
    Inventor: Anthony T. Fiory
  • Patent number: 5294198
    Abstract: A unit having differing thermal emissivities at differing regions thereof is monitored with an infrared camera for deriving a signal having magnitudes representing infrared emission from multiple pixels in the camera field of view. A computer responsive to the signal (a) stores data representing emissivity and standard temperature of the unit at each of the pixels, (b) combines indications of the infrared emission from each pixel and the stored data representing emissivity of each pixel to derive an indication of monitored temperature of each pixel, (c) compares the stored data representing standard temperature of each pixel and the indications of monitored temperature of each pixel, and (d) derives an indication of the deviation between the magnitude of the standard temperature and monitored temperature at each pixel. In response to the indication of the deviation at each pixel, a property of the unit related to the deviations at the pixels is derived.
    Type: Grant
    Filed: October 1, 1991
    Date of Patent: March 15, 1994
    Assignee: Cincinnati Electronics Corporation
    Inventor: Jerry G. Schlagheck
  • Patent number: 5282017
    Abstract: Apparatus for measuring the value of the directional spectral hemispherical reflectance of the surface of a target when not engaging but being spaced from the target employs a hollow elongated member having a longitudinal axis and first and second opposite ends. The area of the first end is relatively large relative to that of the second end. The first end is open. The member has an inner chamber extending between the ends and has an inner surface adapted to reflect light falling within a specified wave band. The member when the apparatus is in use is positioned with the first end adjacent but spaced from a selected portion of the surface of the target. The longitudinal axis is oriented essentially normal to a region on the selected surface which would be engaged by a line coincident with the axis and sufficiently extended outwardly from the first end.
    Type: Grant
    Filed: January 5, 1990
    Date of Patent: January 25, 1994
    Assignee: Quantum Logic Corporation
    Inventors: Ira Kasindorf, Alexander Stein
  • Patent number: 5271084
    Abstract: Method and apparatus for measuring the radiation originating from one side of a wafer of semiconductor material using a pyrometer, wherein non-blackbody compensation radiation is projected onto that side to compensate for the reflectivity of the wafer of material and wherein the intensity of the non-blackbody compensation radiation is controlled subject to the amount of radiation measured by the pyrometer.
    Type: Grant
    Filed: October 6, 1992
    Date of Patent: December 14, 1993
    Assignee: Interuniversitair Micro Elektronica Centrum vzw
    Inventors: Peter M. N. Vandenabeele, Karen I. J. Maex
  • Patent number: 5255286
    Abstract: A multi-point non-invasive, real-time pyrometry-based temperature sensor (200) for simultaneously sensing semiconductor wafer (22) temperature and compensating for wafer emissivity effects. The pyrometer (200) measures the radiant energy that a heated semiconductor wafer (22) emits and coherent beams of light (224) that the semiconductor wafer (22) reflects. As a result, the sensor (200) generates accurate, high-resolution multi-point measurements of semiconductor wafer (22) temperature during a device fabrication process. The pyrometer (200) includes an infrared laser source (202) that directs coherent light beam (203) into beam splitter (204). From the beam splitter (204), the coherent light beam (203) is split into numerous incident coherent beams (210). Beams (210) travel via optical fiber bundles (218) to the surface of semiconductor wafer (22) within the fabrication reactor (80). Each optical fiber bundle (218) collects reflected coherent light beam and radiant energy from wafer (22).
    Type: Grant
    Filed: July 10, 1992
    Date of Patent: October 19, 1993
    Assignee: Texas Instruments Incorporated
    Inventors: Mehrdad M. Moslehi, Habib N. Najm
  • Patent number: 5232284
    Abstract: A radiation clinical thermometer has a probe with an optical guide and an infrared sensor, a detection signal processing section, a body temperature operating section, and a display unit. A filter correction system for setting a correction value based on the transmission wave length characteristics of a filter is also provided. The body temperature operating section receives infrared data, temperature sensitive data, which takes into account the temperature equilibrium between the optical guide and the infrared sensor, and a correction value from the filter correction section so as to calculate body temperature data.
    Type: Grant
    Filed: May 11, 1992
    Date of Patent: August 3, 1993
    Assignee: Citizen Watch Co., Ltd.
    Inventors: Shunji Egawa, Masato Yamada
  • Patent number: 5231595
    Abstract: A pyrometer includes a light source capable of emitting light to at least two wavelengths to a target to be measured. A light measuring member measures the light source and provides output signals representative of those two wavelengths. A second light measuring member measures light reflected by the target and provides second signals corresponding to the two wavelengths. A third light measuring member measures the intensity of the light radiated by the target with respect to those two wavelengths to produce third signals. An emissivity is assumed for the target based on the predetermined wavelengths, and a temperature is calculated on the basis of the minimum value of the difference between the assumed radiation intensity calculated according to the assumed emissivity of the target and the measured radiation intensity in accordance with the third signals.
    Type: Grant
    Filed: October 18, 1991
    Date of Patent: July 27, 1993
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Toshiro Makino, Hiroji Tsujimura, Jiro Arima
  • Patent number: 5226732
    Abstract: An improved contactless temperature measurement system is provided which includes a workpiece, a chamber containing the workpiece with the walls thereof being substantially transmissive to radiation at wavelengths other than a given wavelength and substantially reflective at the given wavelength to remove the dependence of the apparent or measured temperature on the workpiece emissivity variations or fluctuations.
    Type: Grant
    Filed: April 17, 1992
    Date of Patent: July 13, 1993
    Assignee: International Business Machines Corporation
    Inventors: James S. Nakos, Paul E. Bakeman, Jr., Dale P. Hallock, Jerome B. Lasky, Scott L. Pennington
  • Patent number: 5186541
    Abstract: A non-contact infrared temperature sensing system for determining temperature values for a series of targets all having a similar emissivity value, which calculates an emissivity value for the targets based on the sensed total heat radiated from one target, an inputted temperature value for that target, and a temperature value for extraneous radiation from that target. The system then computes, for each subsequent target whose heat radiation is detected, a temperature value for each said target dependent upon the emitted component of radiation, and independent of the extraneous component of radiation from that target.
    Type: Grant
    Filed: October 21, 1991
    Date of Patent: February 16, 1993
    Assignee: Gentri Controls, Inc.
    Inventor: Raymond C. Paulk
  • Patent number: 5169235
    Abstract: A thermometer includes an infrared sensor (14) for receiving infrared radiation to generate a corresponding electrical signal; a reference unit (10) for emitting a standard infrared radiation; a temperature sensor (11) for receiving the standard infrared radiation to generate a corresponding standard electrical signal; a support unit (1, 2) for supporting the infrared sensor and the reference means such that the infrared sensor receives the standard infrared radiation from the reference means in a standby state and infrared radiation from a subject in a measurement state; an arithmetic unit (44) for computing a temperature of the subject based on the electrical signals from the infrared sensor in both the standby and measurement states and from the temperature sensor.
    Type: Grant
    Filed: August 30, 1991
    Date of Patent: December 8, 1992
    Assignee: Hirose Electric Co., Ltd.
    Inventors: Hitoshi Tominaga, Masami Tanaka, Masayoshi Koshino, Hideo Ishibashi
  • Patent number: 5165791
    Abstract: A method of using infrared light for measuring the temperature of a semiconductor element with a surface layer formed by two kinds of materials that have different emissivities and optical reflectances is disclosed. The method includes the step of taking an image with diffused light reflected from the surface of a semiconductor element by an image taking device.
    Type: Grant
    Filed: September 13, 1991
    Date of Patent: November 24, 1992
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Atsushi Miki, Masanori Nishiguchi
  • Patent number: RE34507
    Abstract: A radiation clinical thermometer includes a probe, a detection signal processing section, a body temperature operating section, and a display unit. A filter correction section for setting a correction value based on the transmission wavelength characteristics of a filter is arranged. The body temperature operating section receives infrared data, temperature-sensitive data, and the correction value from the filter correction section so as to calculate body temperature data.
    Type: Grant
    Filed: April 23, 1992
    Date of Patent: January 11, 1994
    Assignee: Citizen Watch Co., Ltd.
    Inventors: Shunji Egawa, Masato Yamada