Patents by Inventor Kenneth Carlisle Johnson

Kenneth Carlisle Johnson 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).

  • Patent number: 11561476
    Abstract: A multifunction UV or DUV (ultraviolet/deep-ultraviolet) lithography system uses a modified Schwarzschild flat-image projection system to achieve diffraction-limited, distortion-free and double-telecentric imaging over a large image field at high numerical aperture. A back-surface primary mirror enables wide-field imaging without large obscuration loss, and additional lens elements enable diffraction-limited and substantially distortion-free, double-telecentric imaging. The system can perform maskless lithography (either source-modulated or spatially-modulated), mask-projection lithography (either conventional imaging or holographic), mask writing, wafer writing, and patterning of large periodic or aperiodic structures such as microlens arrays and spatial light modulators, with accurate field stitching to cover large areas exceeding the image field size.
    Type: Grant
    Filed: July 10, 2021
    Date of Patent: January 24, 2023
    Inventor: Kenneth Carlisle Johnson
  • Publication number: 20230011685
    Abstract: A multifunction UV or DUV (ultraviolet/deep-ultraviolet) lithography system uses a modified Schwarzschild flat-image projection system to achieve diffraction-limited, distortion-free and double-telecentric imaging over a large image field at high numerical aperture. A back-surface primary mirror enables wide-field imaging without large obscuration loss, and additional lens elements enable diffraction-limited and substantially distortion-free, double-telecentric imaging. The system can perform maskless lithography (either source-modulated or spatially-modulated), mask-projection lithography (either conventional imaging or holographic), mask writing, wafer writing, and patterning of large periodic or aperiodic structures such as microlens arrays and spatial light modulators, with accurate field stitching to cover large areas exceeding the image field size.
    Type: Application
    Filed: July 10, 2021
    Publication date: January 12, 2023
    Inventor: Kenneth Carlisle Johnson
  • Patent number: 11520235
    Abstract: A maskless, extreme ultraviolet (EUV) lithography scanner uses an array of microlenses, such as binary-optic, zone-plate lenses, to focus EUV radiation onto an array of focus spots (e.g. about 2 million spots), which are imaged through projection optics (e.g., two EUV mirrors) onto a writing surface (e.g., at 6× reduction, numerical aperture 0.55). The surface is scanned while the spots are modulated to form a high-resolution, digitally synthesized exposure image. The projection system includes a diffractive mirror, which operates in combination with the microlenses to achieve point imaging performance substantially free of geometric and chromatic aberration. Similarly, a holographic EUV lithography stepper can use a diffractive photomask in conjunction with a diffractive projection mirror to achieve substantially aberration-free, full-field imaging performance for high-throughput, mask-projection lithography. Maskless and holographic EUV lithography can both be implemented at the industry-standard 13.
    Type: Grant
    Filed: October 3, 2020
    Date of Patent: December 6, 2022
    Inventor: Kenneth Carlisle Johnson
  • Publication number: 20220107568
    Abstract: A maskless, extreme ultraviolet (EUV) lithography scanner uses an array of microlenses, such as binary-optic, zone-plate lenses, to focus EUV radiation onto an array of focus spots (e.g. about 2 million spots), which are imaged through projection optics (e.g., two EUV mirrors) onto a writing surface (e.g., at 6X reduction, numerical aperture 0.55). The surface is scanned while the spots are modulated to form a high-resolution, digitally synthesized exposure image. The projection system includes a diffractive mirror, which operates in combination with the microlenses to achieve point imaging performance substantially free of geometric and chromatic aberration. Similarly, a holographic EUV lithography stepper can use a diffractive photomask in conjunction with a diffractive projection mirror to achieve substantially aberration-free, full-field imaging performance for high-throughput, mask-projection lithography. Maskless and holographic EUV lithography can both be implemented at the industry-standard 13.
    Type: Application
    Filed: October 3, 2020
    Publication date: April 7, 2022
    Inventor: Kenneth Carlisle Johnson
  • Patent number: 10025079
    Abstract: An actinic, through-pellicle EUV mask inspection or metrology system acquires image information by scanning an array of focused illumination spots across a photomask and detecting the mask reflectance signal from each spot in synchronization with the scan motion. The radiation from each spot is detected by a detector comprising four quadrant sensors to provide information on the angular reflectance distribution, which is sensitive to the reflectance phase. The focal spots are generated from achromatic EUV microlenses (phase-Fresnel, Schupmann doublets), enabling the use of a high-bandwidth, high-power, laser-produced-plasma EUV source for high-throughput operation. The microlens foci are projected through illumination optics (EUV mirrors) onto the focal spots at the mask, and the microlenses nullify the illumination optics' geometric aberrations for substantially aberration-free point imaging.
    Type: Grant
    Filed: September 19, 2016
    Date of Patent: July 17, 2018
    Inventor: Kenneth Carlisle Johnson
  • Publication number: 20170090172
    Abstract: An actinic, through-pellicle EUV mask inspection or metrology system acquires image information by scanning an array of focused illumination spots across a photomask and detecting the mask reflectance signal from each spot in synchronization with the scan motion. The radiation from each spot is detected by a detector comprising four quadrant sensors to provide information on the angular reflectance distribution, which is sensitive to the reflectance phase. The focal spots are generated from achromatic EUV microlenses (phase-Fresnel, Schupmann doublets), enabling the use of a high-bandwidth, high-power, laser-produced-plasma EUV source for high-throughput operation. The microlens foci are projected through illumination optics (EUV mirrors) onto the focal spots at the mask, and the microlenses nullify the illumination optics' geometric aberrations for substantially aberration-free point imaging.
    Type: Application
    Filed: September 19, 2016
    Publication date: March 30, 2017
    Inventor: Kenneth Carlisle Johnson
  • Patent number: 6392752
    Abstract: A scanning microlens array functions in a manner analogous to an array of interference microscopes to provide phase-sensitive, confocal micro-imaging capability. Moreover, the scanning mechanism can effectively perform a phase-modulation function. In this mode of operation, each image point is scanned by multiple microlenses that have fixed, but differing, built-in phase offsets, and the combination of signals acquired from the multiple scans effectively simulate a phase-modulated interference signal.
    Type: Grant
    Filed: June 12, 2000
    Date of Patent: May 21, 2002
    Inventor: Kenneth Carlisle Johnson
  • Patent number: 6301000
    Abstract: A spatial light modulator pixel includes a flexible reflective surface that is electrostatically actuated to control the surface shape and thereby phase-modulate reflected light. The reflected light is filtered by a projection aperture, wherein the phase modulation controls the amount of light from the pixel that is filtered through the aperture. The spatial light modulator includes and array of such pixels, which are imaged onto a conjugate image plane, and each pixel controls the image brightness at a corresponding conjugate image point. High image contrast is achieved by using a dual-flexure pixel design in which two flexure elements operate conjunctively to maintain well-defined diffraction nodes at or near the projection aperture edges over the full modulation range.
    Type: Grant
    Filed: January 11, 2000
    Date of Patent: October 9, 2001
    Inventor: Kenneth Carlisle Johnson
  • Patent number: 6188519
    Abstract: A spatial light modulator pixel comprises a movable reflective surface in which an array of subapertures is formed, wherein each subaperture contains a fixed (non-movable) island reflector. The movable reflector is micromechanically actuated so that the combination of movable and fixed reflectors functions alternately as a plane mirror or as a two-dimensional diffraction grating (i.e., a “bigrating”), depending on the movable reflector's position. The device is useful for applications such as maskless lithography and high-resolution printing.
    Type: Grant
    Filed: January 3, 2000
    Date of Patent: February 13, 2001
    Inventor: Kenneth Carlisle Johnson