Patents Assigned to Ultratech Stepper, Inc.
  • Publication number: 20040173585
    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: Application
    Filed: March 22, 2004
    Publication date: September 9, 2004
    Applicant: ULTRATECH STEPPER, INC.
    Inventors: Somit Talwar, Michael O. Thompson, David A. Markle
  • Patent number: 6777317
    Abstract: A method of forming a doped polycrystalline silicon gate in a Metal Oxide Semiconductor (MOS) device. The method includes forming first an insulation layer on a top surface of a crystalline silicon substrate. Next, an amorphous silicon layer is formed on top of and in contact with the insulation layer and then a dopant is introduced in a top surface layer of the amorphous silicon layer. The top surface of the amorphous silicon layer is irradiated with a laser beam and the heat of the radiation causes the top surface layer to melt and initiates explosive recrystallization (XRC) of the amorphous silicon layer. The XRC process transforms the amorphous silicon layer into a polycrystalline silicon gate and distributes the dopant homogeneously throughout the polycrystalline gate.
    Type: Grant
    Filed: August 29, 2001
    Date of Patent: August 17, 2004
    Assignee: Ultratech Stepper, Inc.
    Inventors: Cindy Seibel, Somit Talwar
  • Patent number: 6777833
    Abstract: A magnetic levitation (maglev) stage apparatus and method is disclosed. The maglev stage includes a movable platen having an upper surface capable of supporting a workpiece. A set of magnet arrays is arranged on the bottom surface of the platen, and first and second side magnet arrays are arranged on opposite sides of the platen. A support frame at least partially surrounds the platen on the first and second sides and the bottom surface. A plurality of motor coils is arranged on the support frame so as to be in operable communication with the set of magnet arrays and the side magnet arrays. The magnet arrays and motor coils are operable to magnetically levitate the platen within the support frame and move the platen in up to six degrees of freedom (DOF), with all forces directed through the center-of-gravity of the platen along the DOF axes. Movable counterweights may also be employed to facilitate the smooth movement of the platen.
    Type: Grant
    Filed: December 17, 2001
    Date of Patent: August 17, 2004
    Assignee: Ultratech Stepper, Inc.
    Inventor: Mark E. Williams
  • Publication number: 20040145671
    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: Application
    Filed: January 14, 2004
    Publication date: July 29, 2004
    Applicant: ULTRATECH STEPPER, INC.
    Inventor: Weijian Wang
  • Patent number: 6753947
    Abstract: A lithography system and method for cost-effective device manufacture that can employ a continuous lithography mode of operation is disclosed, wherein exposure fields are formed with single pulses of radiation. The system includes a pulsed radiation source (14), an illumination system (24), a mask (M), a projection lens (40) and a workpiece stage (50) that supports a workpiece (W) having an image-bearing surface (WS). A radiation source controller (16) and a workpiece stage position system (60), which includes a metrology device (62), are used to coordinate and control the exposure of the mask with radiation pulses so that adjacent radiation pulses form adjacent exposure fields (EF). Where pulse-to-pulse uniformity from the radiation source is lacking, a pulse stabilization system (18) may be optionally used to attain the desired pulse-to-pulse uniformity in exposure dose.
    Type: Grant
    Filed: May 10, 2001
    Date of Patent: June 22, 2004
    Assignee: Ultratech Stepper, Inc.
    Inventors: Dan Meisburger, David A. Markle
  • Patent number: 6747245
    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: November 6, 2002
    Date of Patent: June 8, 2004
    Assignee: Ultratech Stepper, Inc.
    Inventors: Somit Talwar, Michael O. Thompson, David A. Markle
  • Patent number: 6731376
    Abstract: Systems and methods for reducing colinearity effects in the formation of microdevices are disclosed. A mask with at least one column of microdevice cells is illuminated with pulses of radiation such that only a single column is illuminated. Images of the column are used to form adjacent columnar exposure fields on a workpiece. The columnar exposure fields so formed each have a width much less than that of the full exposure field capable of being formed by the projection lens. One method of the invention includes forming each columnar exposure field with a single pulse of radiation while the workpiece moves continuously relative to a projection lens and mask. Another method includes forming each columnar exposure field with a burst of radiation pulses or a long continuous pulse while stepping the workpiece beneath a projection lens between bursts. By forming columnar exposure fields that contain a single row of devices, a substantial number of error sources that contribute to co-linearity error are eliminated.
    Type: Grant
    Filed: October 22, 2001
    Date of Patent: May 4, 2004
    Assignee: Ultratech Stepper, Inc.
    Inventor: David A. Markle
  • Publication number: 20040074895
    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: Application
    Filed: July 18, 2003
    Publication date: April 22, 2004
    Applicant: ULTRATECH STEPPER, INC.
    Inventors: Michael A. Newcomb, Evan R. Mapoles, David P. Gaines, Steve Shannon
  • Publication number: 20040041105
    Abstract: A radiation shield device (100) and method, the apparatus comprising either an absorbing shield (130), a scattering shield (200) or an absorbing and scattering shield (300) arranged in a processing tool (50) that irradiates a workpiece (70) with high-irradiance radiation (80) from a light source (78). The processing tool has a tool portion (66) having an irradiance damage threshold (IDT). The radiation shield device is designed to intercept a portion of the high-irradiance radiation that would otherwise be incident the tool portion, and to ensure that radiation exiting the particular shield comprising the radiation shield device and incident the tool portion has an irradiance below the tool portion irradiance damage threshold. The method includes using the radiation shield device in processing a workpiece using a processing tool.
    Type: Application
    Filed: August 29, 2003
    Publication date: March 4, 2004
    Applicant: ULTRATECH STEPPER, INC.
    Inventors: Andrew M. Hawryluk, Joe Gortych, Yu Chue Fong
  • Patent number: 6680774
    Abstract: A method of, and apparatus for, mechanically masking a workpiece to form exposure exclusion regions is disclosed. The apparatus includes a mask that is arranged atop the photosensitive surface of the workpiece. The mask is opaque to the wavelength of radiation that activates the photosensitive workpiece surface. The mask is placed onto the workpiece prior to lithographic exposure of the workpiece so that the photosensitive material (e.g., negative acting photoresist) can be removed from select regions of the workpiece to provide, for example, electrical contact directly to the workpiece upper surface.
    Type: Grant
    Filed: October 9, 2001
    Date of Patent: January 20, 2004
    Assignee: Ultratech Stepper, Inc.
    Inventor: Konrad Heinle
  • Patent number: 6671235
    Abstract: A method of, and apparatus for, defining disk tracks in magnetic recording media. The track-writing apparatus (20) is capable of forming tracks (340) with a track width (TW) and track spaces (350) with a space width (SW) on a magnetic media disk (70) having an upper surface (70S), wherein the disk comprises a magnetic medium with a thermal diffusion length (X). The apparatus comprises, in order along an optical axis (A1), a laser light source (30) capable of providing a pulsed laser light beam (B1), a light pipe (32), and illumination shaping optical system (40) that provides substantially uniform illumination over an exposure region (ER), and a phase plate (60) having a phase grating (210) with a grating period (p), arranged proximate and substantially parallel to the upper surface of the disk so as to form an periodic irradiance distribution (380) at the surface of the disk when the phase plate is illuminated with the exposure region.
    Type: Grant
    Filed: March 27, 2000
    Date of Patent: December 30, 2003
    Assignee: Ultratech Stepper, Inc.
    Inventors: Andrew M. Hawryluk, Robert D. Hempstead, David A. Markle
  • Patent number: 6645838
    Abstract: A process for activating a doped region (80) or amorphized doped region (34) in a semiconductor substrate (10). The process includes the steps of doping a region of the semiconductor substrate, wherein the region is crystalline or previously amorphized. The next step is forming a conformal layer (40) atop the upper surface (11) of the substrate. The next step is performing at least one of front-side and backside irradiation of the substrate to activate the doped region. The activation may be achieved by heating the doped region to just below the melting point of the doped region, or by melting the doped region but not the crystalline substrate. An alternative process includes the additional step of forming the doped region (amorphized or unamorphized) within or adjacent a deep dopant region (60) and providing sufficient heat to the deep dopant region through at least one of front-side and backside irradiation so that the doped region is activated through explosive recrystallization.
    Type: Grant
    Filed: April 11, 2002
    Date of Patent: November 11, 2003
    Assignee: Ultratech Stepper, Inc.
    Inventors: Somit Talwar, Yun Wang, Michael O. Thompson
  • Patent number: 6635588
    Abstract: Method for controlling heat transferred to a workpiece (W) process region (30) from laser radiation (10) using a thermally induced reflectivity switch layer (60). A film stack (6) is formed having an absorber layer (50) atop the workpiece with a portion covering the process region. The absorber layer absorbs and converts laser radiation into heat. Reflective switch layer (60) is deposited atop the absorber layer. The reflective switch layer comprises one or more layers, e.g. thermal insulator and reflectivity transition layers. The reflective switch layer covering the process region has a temperature related to the temperature of the process region. Reflectivity of the switch layer changes from a low to a high reflectivity state at a critical temperature of the process region, limiting radiation absorbed by the absorber layer by reflecting incident radiation when switched. This limits the amount of heat transferred to the process region from the absorber layer.
    Type: Grant
    Filed: February 19, 2002
    Date of Patent: October 21, 2003
    Assignee: Ultratech Stepper, Inc.
    Inventors: Andrew M. Hawryluk, Somit Talwar, Yun Wang, Michael O. Thompson
  • Patent number: 6635541
    Abstract: A method of the invention comprises forming a partial absorber layer (PAL) over at least one integrated transistor device formed on a semiconductor substrate, and exposing the PAL to radiant energy. A first portion of the radiant energy passes through the PAL and is absorbed in the source and drain regions adjacent a gate region of the integrated transistor device and in the semiconductor substrate underneath the field isolation regions of the integrated device. A second portion of the radiant energy is absorbed by the PAL and is thermally conducted from the PAL to the source and drain regions. The first and second portions of the radiant energy are sufficient to melt the source and drain regions to anneal the junctions of the integrated device.
    Type: Grant
    Filed: September 11, 2000
    Date of Patent: October 21, 2003
    Assignee: Ultratech Stepper, Inc.
    Inventors: Somit Talwar, Yun Wang, Carol Gelatos
  • Patent number: 6617600
    Abstract: A radiation shield device (100) and method, the apparatus comprising either an absorbing shield (130), a scattering shield (200) or an absorbing and scattering shield (300) arranged in a processing tool (50) that irradiates a workpiece (70) with high-irradiance radiation (80) from a light source (78). The processing tool has a tool portion (66) having an irradiance damage threshold (IDT). The radiation shield device is designed to intercept a portion of the high-irradiance radiation that would otherwise be incident the tool portion, and to ensure that radiation exiting the particular shield comprising the radiation shield device and incident the tool portion has an irradiance below the tool portion irradiance damage threshold. The method includes using the radiation shield device in processing a workpiece using a processing tool.
    Type: Grant
    Filed: February 16, 2000
    Date of Patent: September 9, 2003
    Assignee: Ultratech Stepper, Inc.
    Inventors: Andrew M. Hawryluk, Joe Gortych, Yu Chue Fong
  • Patent number: 6617555
    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: August 6, 2001
    Date of Patent: September 9, 2003
    Assignee: Ultratech Stepper, Inc.
    Inventors: Michael A. Newcomb, Evan R. Mapoles, David P. Gaines, Steve Shannon
  • Patent number: 6570656
    Abstract: The closed loop embodiment includes a pulsed laser controller to selectively operate a pulsed laser in a lower-power probe mode or a higher power operational mode. In lower-power probe mode, values of eT (total radiation energy flooding ICs on a silicon wafer), er (fraction of eT specularly reflected), es (fraction of eT scattered) and es (fraction of eT transmitted through wafer) are obtained. A value for ea (fraction of eT absorbed wafer) is calculated i.e. ea=eT−(er+es+et), and ea used by pulsed laser controller with pulsed laser in higher power operational mode to adjust pulsed laser fluence over the duration of a pulse to provide flooding radiation energy sufficient to melt an amorphized silicon surface layer beneath radiation-absorbent material, yet insufficient to melt crystalline silicon or ablate radiation-absorbent material. Open loop embodiment substitutes a separate low-power probe laser for operation in lower-power probe mode.
    Type: Grant
    Filed: April 10, 2000
    Date of Patent: May 27, 2003
    Assignee: Ultratech Stepper, Inc.
    Inventors: James B. Owens, Jr., Somit Talwar, Andrew M. Hawryluk, Yun Wang
  • Patent number: 6556279
    Abstract: A system and method of compensating for image smear that arises when imaging onto a moving workpiece with a single pulse of radiation. The system includes a mask frame capable of supporting a mask to be imaged. The mask frame is operatively connected to a drive unit and is capable of moving in the mask plane. The mask frame is driven in an oscillatory fashion in the mask plane so that when a pulse of radiation illuminates the mask, the mask image moves in the same direction as the moving workpiece, thereby reducing image smear. The present invention is particularly applicable to single-pulse-exposure systems that utilize pulsed radiation sources having relatively long pulse duration, such as flash-lamps or certain types of lasers.
    Type: Grant
    Filed: August 20, 2001
    Date of Patent: April 29, 2003
    Assignee: Ultratech Stepper, Inc.
    Inventors: Dan Meisburger, David A. Markle
  • Patent number: 6554464
    Abstract: A light tunnel (24) comprising a hollow light tunnel body (30) or a solid light tunnel body (80) having a central axis (A1 or A2), a reflective surface (42 or 84) facing the axis, and an output end (54 or 94) having an edge (60 or 106) with a chamfered surface (120 or 130) formed on the edge. The chamfered surface is designed to alter the reflective properties of the reflective surfaces of the light tunnel body near the output end so as to reduce or eliminate edge ringing from the light tunnel body edge. In the case of a knife-edge (340) placed at the output end of the light tunnel body, knife-edge ringing is eliminated by providing a light source (310) in the form of a laser with a large number of spatial modes (M2>30). The present invention is expected to be most useful in cases where time-averaging or other interference-eliminating means prove impossible or impractical, such as with applications requiring only one or a few high-irradiance light pulses that need to uniformly irradiate a workpiece.
    Type: Grant
    Filed: February 16, 2000
    Date of Patent: April 29, 2003
    Assignee: Ultratech Stepper, Inc.
    Inventors: Andrew M. Hawryluk, Yu Chue Fong, David G. Stites, Weijian Wang
  • Patent number: 6534159
    Abstract: An apparatus in accordance with this invention includes an alignment mark that is formed in a substrate. The alignment mark extends across a dice line so that, upon dicing the substrate, the mark is exposed in the substrate's side edge. The mark is formed at a predetermined distance from a position at which a feature is desired to be formed on the substrate's side edge using a mask. Accordingly, the mark is a positional reference that can be used for highly accurate placement of the feature on the side surface of the substrate with the mask. Preferably, the mark is formed of metal or other material enhanced to a size that is readily detectable by an alignment system with which the mark is to be used. The invention also includes methods for making the alignment mark.
    Type: Grant
    Filed: September 10, 1999
    Date of Patent: March 18, 2003
    Assignee: Ultratech Stepper, Inc.
    Inventors: Thomas H Newman, Norbert Kappel