Patents Assigned to Ultratech
  • Patent number: 7326877
    Abstract: Chuck methods and apparatus for supporting a semiconductor substrate and maintaining it at a substantially constant background temperature even when subject to a spatially and temporally varying thermal load. Chuck includes a thermal compensating heater module having a sealed chamber containing heater elements, a wick, and an alkali metal liquid/vapor. The chamber employs heat pipe principles to equalize temperature differences in the module. The spatially varying thermal load is quickly made uniform by thermal conductivity of the heater module. Heatsinking a constant amount of heat from the bottom of the heater module accommodates large temporal variations in the thermal heat load. Constant heat loss is preferably made to be at least as large as the maximum variation in the input heat load, less heat lost through radiation and convection, thus requiring a heat input through electrical heating elements. This allows for temperature control of the chuck, and hence the substrate.
    Type: Grant
    Filed: December 1, 2004
    Date of Patent: February 5, 2008
    Assignee: Ultratech, Inc.
    Inventors: Iqbal A. Shareef, Igor Landau, David A. Markle, Somit Talwar, Michael O. Thompson, Ivelin A. Angelov, Senquan Zhou
  • Patent number: 7292616
    Abstract: Systems and methods for stabilizing a CO2 laser are disclosed. The system includes a detector unit for measuring the power in a select portion of the output beam. The detector unit generates an electrical signal corresponding to the measured power. The modulation frequency of the signal used to modulate the relatively high-frequency radio-frequency (RF) pump signal is filtered from the electrical signal. The filtered electrical signal is then compared to a desired value for the output power in the output beam. Based on the comparison, a modulation control signal for modulating the RF pump signal is formed. The modulation control signal has a varying duty cycle that varies the amount of laser pump power to reduce or eliminate the measured variations in the output beam power. The result is an output beam power that remains stable over time.
    Type: Grant
    Filed: February 9, 2005
    Date of Patent: November 6, 2007
    Assignee: Ultratech, Inc.
    Inventors: Boris Grek, Michael Weitzel, Igor Landau
  • Patent number: 7253376
    Abstract: Methods and apparatus for truncating an image formed with coherent radiation. The optical relay system is adapted to form a line image at the image plane. The image is truncated by a variable aperture at or near the aperture plane conjugate to the image plane, to block progressively increasing portions of an incident coherent radiation beam used to form the line image. An apodizing pupil filter having a maximum transmission or reflection in the center and a transmission or reflection profile that varies with direction corresponding to long direction of the line image is provided in the pupil plane. The apodization is designed to prevent hot-spots from forming in the truncated image and ensures a relatively smooth, flat intensity profile. Thus, one end or another of a coherent line image scanned over a substrate can be truncated during scanning without substantially changing the image intensity extending into the product area.
    Type: Grant
    Filed: January 21, 2005
    Date of Patent: August 7, 2007
    Assignee: Ultratech, Inc.
    Inventors: Shiyu Zhang, Igor Landau, Arnold Lungershausen, David A. Markle, Casey Donaher
  • Patent number: 7238915
    Abstract: Methods and apparatus (100) for scanning a surface (12) of a substrate (10) with an obliquely incident radiation beam (20) over a select scan path (210) to avoid damage (30) to the curved edge (14) of the substrate. The methods and apparatus allow for the substrate edge to be irradiated with the full intensity of the radiation beam, provided that the edge crossing positions avoid a region where the polar angle is less than a scan path critical (SPC) polar angle (?C). At the SPC polar angle the temperatures produced by scanning the beam on the substrate surface and on the edge are the same. The scan path is arranged so the edge crossing positions are located where the polar angle corresponding to each meets or exceeds the SPC polar angle. Ensuring that the substrate edge temperature (TE) remains at or below the substrate surface temperature (TS). The invention has particular utility in laser thermal processing (LTP) of circular silicon substrates when forming transistor-based integrated circuits.
    Type: Grant
    Filed: September 26, 2005
    Date of Patent: July 3, 2007
    Assignee: Ultratech, Inc.
    Inventors: Boris Grek, David A. Markle
  • Patent number: 7231924
    Abstract: A deodorizing apparatus for suppressing odor emanating from a cigarette butt containment vessel. The cigarette butt containment vessel includes a partially enclosed basin cavity into which cigarette butts are collected. In accordance with the present invention, the deodorizing apparatus includes an odor absorption device mounted within the basin cavity of the cigarette butt containment vessel. The odor absorption device includes an absorptive material housing constructed of an air-permeable fabric or mesh that retains the odor absorptive material while permitting airflow between the basin cavity and the interior of the absorptive material housing.
    Type: Grant
    Filed: April 25, 2003
    Date of Patent: June 19, 2007
    Assignee: UltraTech International, Inc.
    Inventors: Mark D. Shaw, J. Tad Heyman, Laurence M. Bierce
  • Patent number: 7176405
    Abstract: A heat shield (10) that facilitates thermally processing a substrate (22) with a radiation beam (150) is disclosed. The heat shield is in the form of a cooled plate adapted to allow the radiation beam to communicate with the substrate upper surface (20) over a radiation beam path (BP), either through an aperture or a transparent region. The heat shield has an operating position that forms a relatively small gap (170) between the lower surface (54) of the heat shield and the upper surface of the wafer. The gap is sized such that the formation of convection cells (200) is suppressed during substrate surface irradiation. If convection cells do form, they are kept out of the radiation beam path. This prevents the radiation beam from wandering from the desired radiation beam path, which in turn allows for uniform heating of the substrate during thermal processing.
    Type: Grant
    Filed: April 22, 2005
    Date of Patent: February 13, 2007
    Assignee: Ultratech, Inc.
    Inventors: Iqbal A. Shareef, Boris Grek, Michael O. Thompson
  • Patent number: 7177099
    Abstract: A 1× projection optical system for deep ultra-violet (DUV) photolithography is disclosed. The optical system is a modified Dyson system capable of imaging a relatively large field at high numerical apertures at DUV wavelengths. The optical system includes a lens group having first and second prisms and four lenses having a positive-negative-positive negative arrangement as arranged in order from the prisms toward the mirror. A projection photolithography system that employs the projection optical system of the invention is also disclosed.
    Type: Grant
    Filed: February 7, 2005
    Date of Patent: February 13, 2007
    Assignee: Ultratech, Inc.
    Inventors: Romeo I. Mercado, Shiyu Zhang
  • Patent number: 7157660
    Abstract: Apparatus and methods for thermally processing a substrate with scanned laser radiation are disclosed. The apparatus includes a continuous radiation source and an optical system that forms an image on a substrate. The image is scanned relative to the substrate surface so that each point in the process region receives a pulse of radiation sufficient to thermally process the region.
    Type: Grant
    Filed: March 22, 2004
    Date of Patent: January 2, 2007
    Assignee: Ultratech, Inc.
    Inventors: Somit Talwar, Michael O. Thompson, David A. Markle
  • Patent number: 7154066
    Abstract: Apparatus and methods for thermally processing a substrate with scanned laser radiation are disclosed. The apparatus includes a continuous radiation source and an optical system that forms an image on a substrate. The image is scanned relative to the substrate surface so that each point in the process region receives a pulse of radiation sufficient to thermally process the region.
    Type: Grant
    Filed: February 26, 2004
    Date of Patent: December 26, 2006
    Assignee: Ultratech, Inc.
    Inventors: Somit Talwar, David A. Markle
  • Patent number: 7148953
    Abstract: A projection optical system suitable for projection photolithography is disclosed. The projection optical system is a modified Wynne-Dyson system capable of imaging a large field over both a narrow and a broad spectral range. The projection optical system includes a positive lens group arranged adjacent to but spaced apart from a concave mirror along the mirror axis on the concave side of the mirror. The system also includes a variable aperture stop so that the system has a variable NA. The projection optical system has two or more common foci within an ultraviolet exposure band and a third common focus in a visible alignment band. A projection photolithography system that employs the projection optical system is also disclosed.
    Type: Grant
    Filed: November 1, 2004
    Date of Patent: December 12, 2006
    Assignee: Ultratech, Inc.
    Inventor: Romeo I. Mercado
  • Patent number: 7148159
    Abstract: Apparatus and method for performing laser thermal annealing (LTA) of a substrate using an annealing radiation beam that is not substantially absorbed in the substrate at room temperature. The method takes advantage of the fact that the absorption of long wavelength radiation (1 micron or greater) in some substrates, such as undoped silicon substrates, is a strong function of temperature. The method includes heating the substrate to a critical temperature where the absorption of long-wavelength annealing radiation is substantial, and then irradiating the substrate with the annealing radiation to generate a temperature capable of annealing the substrate.
    Type: Grant
    Filed: September 29, 2003
    Date of Patent: December 12, 2006
    Assignee: Ultratech, Inc.
    Inventors: Somit Talwar, Michael O. Thompson, Boris Grek, David A. Markle
  • Patent number: 7145104
    Abstract: An apparatus and method for uniformizing the temperature distribution across a semiconductor wafer during radiation annealing of process regions formed in the wafer is disclosed. The method includes forming a silicon layer atop the upper surface of the wafer and irradiating the layer with one or more pulses of radiation having wavelengths that are substantially absorbed by the silicon layer. The silicon layer acts to uniformly absorb the one or more radiation pulses and then transfers the heat from the absorbed radiation to the process regions across the wafer.
    Type: Grant
    Filed: February 26, 2004
    Date of Patent: December 5, 2006
    Assignee: Ultratech, Inc.
    Inventors: Somit Talwar, Michael O. Thompson
  • Patent number: 7116496
    Abstract: An optical system for projection photolithography is disclosed. The optical system is a modified Dyson system capable of imaging a large field over both a narrow and a broad spectral range. The optical system includes a positive lens group having a positive subgroup of elements that includes at least a plano-convex element and a negative subgroup that includes at least a negative meniscus element. The lens subgroups are separated by a small air space. The positive and negative subgroups constitute a main lens group arranged adjacent to but spaced apart from a concave mirror along the mirror axis. The system also includes a variable aperture stop so that the system has a variable NA. A projection photolithography system that employs the optical system is also disclosed.
    Type: Grant
    Filed: October 29, 2004
    Date of Patent: October 3, 2006
    Assignee: Ultratech, Inc.
    Inventor: Romeo I. Mercado
  • Patent number: 7098155
    Abstract: Apparatus and method for performing laser thermal annealing (LTA) of a substrate using an annealing radiation beam that is not substantially absorbed in the substrate at room temperature. The method takes advantage of the fact that the absorption of long wavelength radiation (1 micron or greater) in some substrates, such as undoped silicon substrates, is a strong function of temperature. The method includes heating the substrate to a critical temperature where the absorption of long-wavelength annealing radiation is substantial, and then irradiating the substrate with the annealing radiation to generate a temperature capable of annealing the substrate.
    Type: Grant
    Filed: January 22, 2004
    Date of Patent: August 29, 2006
    Assignee: Ultratech, Inc.
    Inventors: Somit Talwar, David A. Markle
  • Patent number: 7095904
    Abstract: A method and apparatus (10) for determining a best focus position of an object (30) relative to a reference position (e.g., axis A) of a dark-field optical imaging system (20), with an effective focusing range up to 10 times of the depth of field of the system. The method includes the steps of first forming a dark-field image of the object at different focus positions (zm). Each dark-field image has a corresponding image intensity distribution with an average intensity and a variance of intensity. The next step is forming a set of contrast values by calculating a contrast value (Cm) for each dark-field image based on the variance and the average intensity. The last step is determining the best focus position by fitting a Lorentzian function to the set of contrast values plotted as a function of the different focus positions and identifying the focus position associated with the maximum contract value (Cmax).
    Type: Grant
    Filed: January 14, 2004
    Date of Patent: August 22, 2006
    Assignee: Ultratech, Inc.
    Inventor: Weijian Wang
  • Publication number: 20060176917
    Abstract: Systems and methods for stabilizing a CO2 laser are disclosed. The system includes a detector unit for measuring the power in a select portion of the output beam. The detector unit generates an electrical signal corresponding to the measured power. The modulation frequency of the signal used to modulate the relatively high-frequency radio-frequency (RF) pump signal is filtered from the electrical signal. The filtered electrical signal is then compared to a desired value for the output power in the output beam. Based on the comparison, a modulation control signal for modulating the RF pump signal is formed. The modulation control signal has a varying duty cycle that varies the amount of laser pump power to reduce or eliminate the measured variations in the output beam power. The result is an output beam power that remains stable over time.
    Type: Application
    Filed: February 9, 2005
    Publication date: August 10, 2006
    Applicant: Ultratech, Inc.
    Inventors: Boris Grek, Michael Weitzel, Igor Landau
  • Patent number: 7049544
    Abstract: A beamsplitter apparatus for use with high-power radiation is disclosed. The apparatus includes a thermally conductive frame with a central aperture. The frame holds a window in the central aperture at the window's periphery. The window includes a diamond substrate with an optional coating formed thereon. Because the substrate is diamond and the frame is thermally conductive, the window is less susceptible to thermal effects caused by absorption of the incident radiation by the window. Thus, the original flatness of the widow surfaces is preserved, and variations in its index of refraction will be minimal. The result is that high-power radiation beams reflected from and transmitted by the widow remain substantially undistorted.
    Type: Grant
    Filed: March 26, 2004
    Date of Patent: May 23, 2006
    Assignee: Ultratech, Inc.
    Inventor: Igor Landau
  • Patent number: 6989515
    Abstract: An image stabilization apparatus and method for stabilizing the imaging of a high-performance optical system prone to imaging instabilities from thermal effects. Thermal instabilities within the lens, such as convection, can result in image placement errors in a high-performance optical system. The apparatus includes a heating element arranged on the upper surface of the optical system to provide heat to one or more gas-filled spaces in the optical system. An insulating blanket covers a portion of the optical system to uniformize the heating of the optical system and increase efficiency of the apparatus. The gas in the spaces is heated so that the warmer gases reside near the upper portion of the optical system, while the cooler gases reside near the lower portion of the optical system. This creates a stable thermal environment within the lens system, thereby stabilizing the imaging. Optionally gas can be flowed over the lower surface to keep heat from heating the lower portion of the optical system.
    Type: Grant
    Filed: July 18, 2003
    Date of Patent: January 24, 2006
    Assignee: Ultratech, Inc.
    Inventors: Michael A. Newcomb, Evan R. Mapoles, David P. Gaines, Steve Shannon
  • Patent number: 6898306
    Abstract: A method of measuring machine alignment offset of an optical machine having an alignment system, so that subsequent processing of substrates on set of optical machines can be performed in a machine-independent manner. The optical machine forms overlayed images of first and second patterns formed on either one or two reticles onto a substrate at respective first and second levels. The method of the invention includes forming a virtual zero-offset alignment pattern and a virtual zero-offset metrology pattern and imaging first and second metrology patterns on the substrate at the first and second levels, respectively. The second metrology pattern is aligned to the first metrology pattern using the zero-offset alignment pattern so that the exposures are performed in an overlayed manner. The first and second metrology patterns are based on the virtual zero-offset metrology pattern.
    Type: Grant
    Filed: May 14, 2001
    Date of Patent: May 24, 2005
    Assignee: Ultratech, Inc.
    Inventor: Shin-Yee Lu
  • Patent number: 6879383
    Abstract: An optical system for projection photolithography is disclosed. The optical system is a modified Dyson system capable of imaging a large field over a broad spectral range. The optical system includes a positive lens group having three elements: a plano-convex element and two negative meniscus elements. The lens group is arranged adjacent to but spaced apart from a concave mirror along the mirror axis. A projection photolithography system that employs the optical system is also disclosed.
    Type: Grant
    Filed: December 27, 2002
    Date of Patent: April 12, 2005
    Assignee: Ultratech, Inc.
    Inventor: Romeo I. Mercado