Patents by Inventor Henry I. Smith
Henry I. Smith 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).
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Patent number: 7150910Abstract: A structure including a grating and a semiconductor nanocrystal layer on the grating, can be a laser. The semiconductor nanocrystal layer can include a plurality of semiconductor nanocrystals including a Group II–VI compound, the nanocrystals being distributed in a metal oxide matrix. The grating can have a periodicity from 200 nm to 500 nm.Type: GrantFiled: November 15, 2002Date of Patent: December 19, 2006Assignee: Massachusetts Institute of TechnologyInventors: Hans J. Eisler, Vikram C. Sundar, Michael E. Walsh, Victor I. Klimov, Moungi G. Bawendi, Henry I. Smith
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Patent number: 7148496Abstract: A system and method are disclosed for providing error correction in an imaging system. The system includes an error determination unit for determining an amount of error associated with a spot at (x,y) in a binary pattern to be imaged, a determination unit for determining the location of a nearest exposed spot at (xi, yi) for each spot at (x,y), and a dose modification unit for modifying an exposure dose at the nearest exposed spot at (xi, yi) for each spot at (x,y).Type: GrantFiled: April 13, 2004Date of Patent: December 12, 2006Assignee: Massachusetts Institute of TechnologyInventors: Rajesh Menon, Dario Gil, George Barbastathis, Henry I. Smith
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Patent number: 6960773Abstract: A maskless lithography system is disclosed that includes an array of blazed diffractive zone plates, each of which focuses an energy beam into an array of images in order to create a permanent pattern on an adjacent substrate in certain embodiments. In further embodiments, an array of apodized diffractive elements may also be used.Type: GrantFiled: July 21, 2003Date of Patent: November 1, 2005Assignee: Massachusetts Institute of TechnologyInventors: Rajesh Menon, Dario Gil, David Carter, Henry I. Smith, George Barbastathis
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Patent number: 6894292Abstract: A maskless lithography system is disclosed that includes an array of focusing elements, each of which focuses an energy beam from an array of sources into an array of focal spots in order to create a permanent pattern on an adjacent substrate.Type: GrantFiled: July 28, 2003Date of Patent: May 17, 2005Assignee: Massachusetts Institute of TechnologyInventors: Dario Gil, Rajesh Menon, David Carter, Henry I. Smith, George Barbastathis
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Patent number: 6822248Abstract: Fine positioning of a shaped or patterned charged particle beam without use of intrusive fiducial marks is achieved by providing a dithered shadow pattern, preferably in the form of a grid, within the shaped or patterned charged particle beam. Light output from fiducial marks preferably formed of a scintillating material is reduced when the dithered shadow pattern is incident on some or all of the fiducial marks. The timing of the incidence of the shadow pattern on fiducial marks indicates the position of the shaped or patterned charged particle beam such that correction of the beam position on the target can be corrected to a small fraction of system resolution. The dither pattern and repetition period is chosen to avoid interference with uniformity of beam illumination of the target. Feedback of position error thus provides phase locked position correction in real time and is suitable for mask making since the fiducial marks are not intrusive.Type: GrantFiled: March 15, 2001Date of Patent: November 23, 2004Assignee: International Business Machines CorporationInventors: Juan Ferrera, James G. Goodberlet, Timothy R. Groves, John G. Hartley, Mark K. Mondol, Mark L. Schattenburg, Henry I. Smith
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Publication number: 20040135100Abstract: A method is disclosed for forming an array of focusing elements for use in a lithography system. In accordance with an embodiment, the method includes the steps of providing a master element that includes at least one diffractive pattern at a first location with respect to a target surface, illuminating the master element to produce a first diffractive pattern on the target surface at the first location, moving the master element with respect to the target surface to a second location with respect to the target surface, and illuminating the master element to produce a second diffractive pattern on the target surface at the second location.Type: ApplicationFiled: October 2, 2003Publication date: July 15, 2004Inventors: Rajesh Menon, Dario Gil, David J. Carter, George Barbastathis, Henry I. Smith
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Publication number: 20040131946Abstract: A method is disclosed for forming an array of focusing elements for use in a lithography system. The method involves varying an exposure characteristic over an area to create a focusing element that varies in thickness in certain embodiments. In further embodiments, the method includes the steps of providing a first pattern via lithography in a substrate, depositing a conductive absorber material on the substrate, applying an electrical potential to at least a first portion of the conductive absorber material, leaving a second portion of the conductive material without the electrical potential, and etching the second portion of the conductive material to provide a first pattern on the substrate that is aligned with the first portion of the conductive absorber material.Type: ApplicationFiled: October 2, 2003Publication date: July 8, 2004Inventors: Dario Gil, Jeffrey T. Hastings, James G. Goodberlet, Rajesh Menon, David J. Carter, Henry I. Smith
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Publication number: 20040124372Abstract: A maskless lithography system is disclosed that includes an array of focusing elements, each of which focuses an energy beam from an array of sources into an array of focal spots in order to create a permanent pattern on an adjacent substrate.Type: ApplicationFiled: July 28, 2003Publication date: July 1, 2004Inventors: Dario Gil, Rajesh Menon, David Carter, Henry I. Smith, George Barbastathis
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Publication number: 20040069957Abstract: A maskiess lithography system is disclosed that includes an array of blazed diffractive zone plates, each of which focuses an energy beam into an array of images in order to create a permanent pattern on an adjacent substrate in certain embodiments. In further embodiments, an array of apodized diffractive elements may also be used.Type: ApplicationFiled: July 21, 2003Publication date: April 15, 2004Inventors: Rajesh Menon, Dario Gil, David Carter, Henry I. Smith, George Barbastathis
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Publication number: 20040037503Abstract: A diffraction grating of non-uniform strength is introduced into an optical waveguide by modulating its width. The waveguide may be fabricated using one of several planar processing techniques. Varying the size, position, and/or thickness of the grating teeth provides the desired variation of grating strength. Certain functional variations of grating strength suppress side-lobe levels in the grating reflection and transmission spectra. This process, termed apodization, is necessary for precise wavelength filtering and dispersion compensation. If desired, different periodicity gratings can be introduced in each side of the waveguide, multiple periodicities can be superimposed, the grating can be angled with respect to the waveguide, and the grating period and phase can be varied.Type: ApplicationFiled: May 28, 2003Publication date: February 26, 2004Inventors: Jeffrey T. Hastings, Michael H. Lim, Henry I. Smith
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Publication number: 20040004982Abstract: A structure including a grating and a semiconductor nanocrystal layer on the grating, can be a laser. The semiconductor nanocrystal layer can include a plurality of semiconductor nanocrystals including a Group II-VI compound, the nanocrystals being distributed in a metal oxide matrix. The grating can have a periodicity from 200 nm to 500 nm.Type: ApplicationFiled: November 15, 2002Publication date: January 8, 2004Inventors: Hans J. Eisler, Vikram C. Sundar, Michael E. Walsh, Victor I. Klimov, Moungi G. Bawendi, Henry I. Smith
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Patent number: 6522411Abstract: An apparatus and method of measuring the gap between one substantially planar object, such as a mask, and a second planar object, such as a substrate. The invention achieves a high degree of sensitivity, accuracy, capture range, and reliability, through a novel design of a mark located only on the mask-plate. The light is inclined to the surfaces so associated optical components do not interrupt the exposing beam used in lithography. The same optics are used as for aligning overlay. Each gapping mark on the mask-plate includes one or more two-dimensional gratings, each with period constant in the incident plane, but varying in the transverse plane. When illuminated, two images are formed of each of the two-dimensional gratings, with fringes resulting from interference between paths having traveled different distances through the gap and the mask-plate as a result of successive diffractions and reflections.Type: GrantFiled: May 25, 2000Date of Patent: February 18, 2003Assignee: Massachusetts Institute of TechnologyInventors: Euclid E. Moon, Patrick N. Everett, Henry I. Smith
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Publication number: 20020130274Abstract: Fine positioning of a shaped or patterned charged particle beam without use of intrusive fiducial marks is achieved by providing a dithered shadow pattern, preferably in the form of a grid, within the shaped or patterned charged particle beam. Light output from fiducial marks preferably formed of a scintillating material is reduced when the dithered shadow pattern is incident on some or all of the fiducial marks. The timing of the incidence of the shadow pattern on fiducial marks indicates the position of the shaped or patterned charged particle beam such that correction of the beam position on the target can be corrected to a small fraction of system resolution. The dither pattern and repetition period is chosen to avoid interference with uniformity of beam illumination of the target. Feedback of position error thus provides phase locked position correction in real time and is suitable for mask making since the fiducial marks are not intrusive.Type: ApplicationFiled: March 15, 2001Publication date: September 19, 2002Applicant: International Busines Machines CorporationInventors: Juan Ferrera, James G. Goodberlet, Timothy R. Groves, John G. Hartley, Mark K. Mondol, Mark L. Schattenburg, Henry I. Smith
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Patent number: 6404481Abstract: Techniques are disclosed to compensate for distortions in lithography by locally heating the membrane in a lithographic mask. The techniques may be used both to shrink and to expand areas of the mask locally, in order to adjust for varying magnitudes and signs of distortion. In one embodiment the correction method comprises two steps: (1) A send-ahead wafer is exposed and measured by conventional means to determine the overlay errors at several points throughout the field. (2) During exposure of subsequent wafers, calibrated beams of light are focused on the mask. The heating from the absorbed light produces displacements that compensate for the overlay errors measured with the send-ahead wafer. Any source of distortion may be corrected—for example, distortion appearing on the mask initially, distortion that only develops on the mask over time, or distortion on the wafer.Type: GrantFiled: May 25, 2000Date of Patent: June 11, 2002Assignees: Board of Supervisors of Louisiana State University and Agricultural and Mechanical College, Massachusetts Institute of TechnologyInventors: Martin Feldman, Henry I. Smith, Ken-Ichi Murooka, Michael H. Lim
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Patent number: 6088103Abstract: Alignment marks on first and second plates include a plurality of periodic gratings. A grating on a first plate has a period or pitch p.sub.1 paired up with a grating on the second plate that has a slightly different period p.sub.2. A grating on the first plate having a period p.sub.3 is paired up with a grating on the second plate having a slightly different period p.sub.4. Illuminating the gratings produces a first interference pattern characterized by a first interference phase where beams diffracted from the first and second gratings overlap and a second interference pattern characterized by a second interference phase where beams diffracted from the third and fourth gratings overlap. The plates are moved until the difference between the first and second interference phases correspond to a predetermined interference phase difference. Further invention uses an interrupted-grating pattern on the second plate with certain advantages.Type: GrantFiled: September 9, 1998Date of Patent: July 11, 2000Assignee: Massachusetts Institute of TechnologyInventors: Patrick N. Everett, Euclid E. Moon, Henry I. Smith
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Patent number: 5915051Abstract: A wavelength-selective optical switch having a first input port for accepting a plurality of copropagating optical channels, each of the channels having a distinct wavelength band. The optical switch includes first and second output ports. A wavelength-selective optical filter is connected to receive the copropagating optical channels from the first input port to extract a selected one of the channels while allowing the remaining channels to copropagate to the first output port. An interferometric switch is connected to receive the selected extracted channel; the interferometric switch includes a controller for controlling propagation of the selected extracted channel to either the second output port, the optical filter, or both. The optical filter is connected to receive from the interferometric switch an optical channel to be combined with the remaining copropagating channels and all directed to the first output port.Type: GrantFiled: January 21, 1997Date of Patent: June 22, 1999Assignee: Massascusetts Institute of TechnologyInventors: Jay N. Damask, Thomas E. Murphy, Juan Ferrera, Michael Hong Yeol Lim, Henry I. Smith, Hermann A. Haus
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Patent number: 5900637Abstract: An array of Fresnel zone plates is illuminated by parallel beamlets of narrow-band electromagnetic radiation. The individual zone plates focus a significant fraction of the incident radiation to foci on a substrate located at least several micrometers distant. The beamlets are capable of being individually turned on or off by shutters, or by deflecting small mirrors that would otherwise direct a beamlet to its Fresnel zone plate. Pattern generation is accomplished by moving the substrate while multiplexing the individual beamlets on or off.Type: GrantFiled: May 30, 1997Date of Patent: May 4, 1999Assignee: Massachusetts Institute of TechnologyInventor: Henry I. Smith
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Patent number: 5892230Abstract: A scintillating fiducial pattern, and methods of fabricating and using same, on a substrate or a resist/substrate composite, where the scintillating fiducial pattern is used in a spatial referencing scheme. The invention includes the use of a scintillating fiducial pattern as alignment or reference marks on a resist/substrate composite, into which a pattern or feature is to be defined. The invention includes the use of a scintillating fiducial in a mask alignment scheme. The invention includes the use of a scintillating fiducial grid or grating in conjunction with an energy beam locating method, or spatial-phase-locked electron-beam lithography. Spatial referencing to the scintillating fiducial grid, or grating, may be implemented with a delay-locked loop, which locks the phase of a signal from the scintillating grid, or grating, to the phase of a known signal.Type: GrantFiled: May 29, 1997Date of Patent: April 6, 1999Assignee: Massachusetts Institute of TechnologyInventors: James G. Goodberlet, Henry I. Smith
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Patent number: 5808742Abstract: Alignment marks on first and second plates include a plurality of periodic gratings. A grating on a first plate has a period or pitch p.sub.1 paired up with a grating on the second plate that has a slightly different period p.sub.2. A grating on the first plate having a period p.sub.3 is paired up with a grating on the second plate having a slightly different period p.sub.4. Illuminating the gratings produces a first interference pattern characterized by a first interference phase where beams diffracted from the first and second gratings overlap and a second interference pattern characterized by a second interference phase where beams diffracted from the third and fourth gratings overlap. The plates are moved until the difference between the first and second interference phases correspond to a predetermined interference phase difference.Further invention uses an interrupted-grating pattern on the second plate with certain advantages.Type: GrantFiled: May 28, 1996Date of Patent: September 15, 1998Assignee: Massachusetts Institute of TechnologyInventors: Patrick N. Everett, Euclid Eberle Moon, Henry I. Smith
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Patent number: 5809103Abstract: X-ray masking apparatus includes a frame having a supporting rim surrounding an x-ray transparent region, a thin membrane of hard inorganic x-ray transparent material attached at its periphery to the supporting rim covering the x-ray transparent region and a layer of x-ray opaque material on the thin membrane inside the x-ray transparent region arranged in a pattern to selectively transmit x-ray energy entering the x-ray transparent region through the membrane to a predetermined image plane separated from the layer by the thin membrane.Type: GrantFiled: December 20, 1996Date of Patent: September 15, 1998Assignee: Massachusetts Institute of TechnologyInventors: Henry I. Smith, Michael Lim, James Carter, Mark Schattenburg