Patents by Inventor Yung-Ho Alex Chuang
Yung-Ho Alex Chuang 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: 9891177Abstract: A wafer scanning system includes imaging collection optics to reduce the effective spot size. Smaller spot size decreases the number of photons scattered by the surface proportionally to the area of the spot. Air scatter is also reduced. TDI is used to produce a wafer image based on a plurality of image signals integrated over the direction of linear motion of the wafer. An illumination system floods the wafer with light, and the task of creating the spot is allocated to the imaging collection optics.Type: GrantFiled: October 3, 2014Date of Patent: February 13, 2018Assignee: KLA-Tencor CorporationInventors: Jijen Vazhaeparambil, Guoheng Zhao, Daniel Kavaldjiev, Anatoly Romanovsky, Ivan Maleev, Christian Wolters, Stephen Biellak, Bret Whiteside, Donald Pettibone, Yung-Ho Alex Chuang, David W. Shortt
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Patent number: 9865447Abstract: The broadband light source includes a gas containment structure and a pump laser for generating a pump beam including illumination of a wavelength near that of a weak absorption line of a neutral gas contained in the gas containment structure. The broadband light source also includes anamorphic optics for focusing the pump beam into an elliptical beam waist positioned in or near the center of the gas containment structure. The broadband light source also includes collection optics for collecting broadband radiation emitted by the plasma in a direction aligned with a longer axis of the elliptical beam waist.Type: GrantFiled: October 4, 2016Date of Patent: January 9, 2018Assignee: KLA-Tencor CorporationInventors: Yung-Ho Alex Chuang, Xiaoxu Lu, Justin Liou, John Fielden
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Patent number: 9860466Abstract: Pixel aperture size adjustment in a linear sensor is achieved by applying more negative control voltages to central regions of the pixel's resistive control gate, and applying more positive control voltages to the gate's end portions. These control voltages cause the resistive control gate to generate an electric field that drives photoelectrons generated in a selected portion of the pixel's light sensitive region into a charge accumulation region for subsequent measurement, and drives photoelectrons generated in other portions of the pixel's light sensitive region away from the charge accumulation region for subsequent discard or simultaneous readout. A system utilizes optics to direct light received at different angles or locations from a sample into corresponding different portions of each pixel's light sensitive region.Type: GrantFiled: May 12, 2016Date of Patent: January 2, 2018Assignee: KLA-Tencor CorporationInventors: Yung-Ho Alex Chuang, John Fielden, David L. Brown, Jingjing Zhang, Keith Lyon, Mark Shi Wang
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Publication number: 20170338257Abstract: An image sensor for short-wavelength light includes a semiconductor membrane, circuit elements formed on one surface of the semiconductor membrane, and a pure boron layer on the other surface of the semiconductor membrane. An anti-reflection or protective layer is formed on top of the pure boron layer. This image sensor has high efficiency and good stability even under continuous use at high flux for multiple years. The image sensor may be fabricated using CCD (charge coupled device) or CMOS (complementary metal oxide semiconductor) technology. The image sensor may be a two-dimensional area sensor, or a one-dimensional array sensor.Type: ApplicationFiled: August 4, 2017Publication date: November 23, 2017Inventors: Masaharu Muramatsu, Hisanori Suzuki, Yasuhito Yoneta, Shinya Otsuka, Jehn-Huar Chern, David L. Brown, Yung-Ho Alex Chuang, John Fielden, Venkatraman Iyer
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Publication number: 20170329025Abstract: A scanning electron microscope incorporates a multi-pixel solid-state electron detector. The multi-pixel solid-state detector may detect back-scattered and/or secondary electrons. The multi-pixel solid-state detector may incorporate analog-to-digital converters and other circuits. The multi-pixel solid state detector may be capable of approximately determining the energy of incident electrons and/or may contain circuits for processing or analyzing the electron signals. The multi-pixel solid state detector is suitable for high-speed operation such as at a speed of about 100 MHz or higher. The scanning electron microscope may be used for reviewing, inspecting or measuring a sample such as unpatterned semiconductor wafer, a patterned semiconductor wafer, a reticle or a photomask. A method of reviewing or inspecting a sample is also described.Type: ApplicationFiled: August 2, 2017Publication date: November 16, 2017Inventors: David L. Brown, Yung-Ho Alex Chuang, John Fielden, Marcel Trimpl, Jingjing Zhang, Devis Contarato, Venkatraman Iyer
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Patent number: 9818887Abstract: An inspection system including an optical system (optics) to direct light from an illumination source to a sample, and to direct light reflected/scattered from the sample to one or more image sensors. At least one image sensor of the system is formed on a semiconductor membrane including an epitaxial layer having opposing surfaces, with circuit elements formed on one surface of the epitaxial layer, and a pure boron layer on the other surface of the epitaxial layer. The image sensor may be fabricated using CCD (charge coupled device) or CMOS (complementary metal oxide semiconductor) technology. The image sensor may be a two-dimensional area sensor, or a one-dimensional array sensor. The image sensor can be included in an electron-bombarded image sensor and/or in an inspection system.Type: GrantFiled: June 14, 2016Date of Patent: November 14, 2017Assignee: KLA-Tencor CorporationInventors: Jehn-Huar Chern, Ali R. Ehsani, Gildardo Delgado, David L. Brown, Yung-Ho Alex Chuang, John Fielden
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Publication number: 20170323716Abstract: A laser assembly for generating laser output light at an output wavelength of approximately 183 nm includes a fundamental laser, an optical parametric system (OPS), a fifth harmonic generator, and a frequency mixing module. The fundamental laser generates fundamental light at a fundamental frequency. The OPS generates a down-converted signal at a down-converted frequency. The fifth harmonic generator generates a fifth harmonic of the fundamental light. The frequency mixing module mixes the down-converted signal and the fifth harmonic to produce the laser output light at a frequency equal to a sum of the fifth harmonic frequency and the down-converted frequency. The OPS generates the down-converted signal by generating a down-converted seed signal at the down-converted frequency, and then mixing the down-converted seed signal with a portion of the fundamental light.Type: ApplicationFiled: July 26, 2017Publication date: November 9, 2017Inventors: Yung-Ho Alex Chuang, J. Joseph Armstrong, Yujun Deng, Vladimir Dribinski, John Fielden, Jidong Zhang
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Publication number: 20170295334Abstract: A dual-column-parallel image CCD sensor utilizes a dual-column-parallel readout circuit including two pairs of cross-connected transfer gates to alternately transfer pixel data (charges) from a pair of adjacent pixel columns to a shared output circuit at high speed with low noise. Charges transferred along the two adjacent pixel columns at a line clock rate are alternately passed by the transfer gates to a summing gate that is operated at twice the line clock rate to pass the image charges to the shared output circuit. A symmetrical Y-shaped diffusion is utilized in one embodiment to merge the image charges from the two pixel columns. A method of driving the dual-column-parallel CCD sensor with line clock synchronization is also described. A method of inspecting a sample using the dual-column-parallel CCD sensor is also described.Type: ApplicationFiled: October 28, 2016Publication date: October 12, 2017Inventors: Yung-Ho Alex Chuang, Jingjing Zhang, Sharon Zamek, John Fielden, Devis Contarato, David L. Brown
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Publication number: 20170278694Abstract: A high brightness laser-sustained broadband light source includes a gas containment structure and a pump laser configured to generate a pump beam including illumination of a wavelength at least proximate to a weak absorption line of a neutral gas contained in the gas containment structure. The broadband light source includes one or more anamorphic illumination optics configured to focus the pump beam into an approximately elliptical beam waist positioned in or proximate to the center of the gas containment structure. The broadband light source includes one or more first collection optics configured to collect broadband radiation emitted by the plasma in a direction substantially aligned with a longer axis of the elliptical beam waist.Type: ApplicationFiled: October 4, 2016Publication date: September 28, 2017Inventors: Yung-Ho Alex Chuang, Xiaoxu Lu, Justin Liou, John Fielden
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Patent number: 9767986Abstract: A scanning electron microscope incorporates a multi-pixel solid-state electron detector. The multi-pixel solid-state detector may detect back-scattered and/or secondary electrons. The multi-pixel solid-state detector may incorporate analog-to-digital converters and other circuits. The multi-pixel solid state detector may be capable of approximately determining the energy of incident electrons and/or may contain circuits for processing or analyzing the electron signals. The multi-pixel solid state detector is suitable for high-speed operation such as at a speed of about 100 MHz or higher. The scanning electron microscope may be used for reviewing, inspecting or measuring a sample such as unpatterned semiconductor wafer, a patterned semiconductor wafer, a reticle or a photomask. A method of reviewing or inspecting a sample is also described.Type: GrantFiled: August 25, 2015Date of Patent: September 19, 2017Assignee: KLA-Tencor CorporationInventors: David L. Brown, Yung-Ho Alex Chuang, John Fielden, Marcel Trimpl, Jingjing Zhang, Devis Contarato, Venkatraman Iyer
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Patent number: 9768577Abstract: A pulse multiplier includes a beam splitter and one or more mirrors. The beam splitter receives a series of input laser pulses and directs part of the energy of each pulse into a ring cavity. After circulating around the ring cavity, part of the pulse energy leaves the ring cavity through the beam splitter and part of the energy is recirculated. By selecting the ring cavity optical path length, the repetition rate of an output series of laser pulses can be made to be a multiple of the input repetition rate. The relative energies of the output pulses can be controlled by choosing the transmission and reflection coefficients of the beam splitter. This pulse multiplier can inexpensively reduce the peak power per pulse while increasing the number of pulses per second with minimal total power loss.Type: GrantFiled: August 21, 2015Date of Patent: September 19, 2017Assignee: KLA-Tencor CorporationInventors: Yung-Ho Alex Chuang, Justin Dianhuan Liou, J. Joseph Armstrong, Yujun Deng
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Patent number: 9748294Abstract: An image sensor for short-wavelength light includes a semiconductor membrane, circuit elements formed on one surface of the semiconductor membrane, and a pure boron layer on the other surface of the semiconductor membrane. An anti-reflection or protective layer is formed on top of the pure boron layer. This image sensor has high efficiency and good stability even under continuous use at high flux for multiple years. The image sensor may be fabricated using CCD (charge coupled device) or CMOS (complementary metal oxide semiconductor) technology. The image sensor may be a two-dimensional area sensor, or a one-dimensional array sensor.Type: GrantFiled: January 7, 2015Date of Patent: August 29, 2017Assignees: Hamamatsu Photonics K.K., KLA-Tencor CorporationInventors: Masaharu Muramatsu, Hisanori Suzuki, Yasuhito Yoneta, Shinya Otsuka, Jehn-Huar Chem, David L. Brown, Yung-Ho Alex Chuang, John Fielden, Venkatraman Iyer
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Patent number: 9748729Abstract: A laser assembly for generating laser output light at an output wavelength of approximately 183 nm includes a fundamental laser, an optical parametric system (OPS), a fifth harmonic generator, and a frequency mixing module. The fundamental laser generates fundamental light at a fundamental frequency. The OPS generates a down-converted signal at a down-converted frequency. The fifth harmonic generator generates a fifth harmonic of the fundamental light. The frequency mixing module mixes the down-converted signal and the fifth harmonic to produce the laser output light at a frequency equal to a sum of the fifth harmonic frequency and the down-converted frequency. The OPS generates the down-converted signal by generating a down-converted seed signal at the down-converted frequency, and then mixing the down-converted seed signal with a portion of the fundamental light.Type: GrantFiled: October 1, 2015Date of Patent: August 29, 2017Assignee: KLA-Tencor CorporationInventors: Yung-Ho Alex Chuang, J. Joseph Armstrong, Yujun Deng, Vladimir Dribinski, John Fielden, Jidong Zhang
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Publication number: 20170229829Abstract: Laser and inspection systems that generate laser output light at sub-200 nm wavelengths using fundamental light at approximately 1064 nm. A second harmonic generator module generates second harmonic light directed to both an optical parametric (OP) module, which generates down-converted signal (idler light), and to a fifth harmonic generator module, which generates fifth harmonic light. The OP module includes an optical parametric oscillator that is configured to generate the idler signal at approximately 0.5 times the fundamental frequency. The idler light and fifth harmonic light are then mixed by a frequency mixing module to generate the laser output light having an output frequency equal to approximately 5.5 times the fundamental frequency.Type: ApplicationFiled: April 24, 2017Publication date: August 10, 2017Inventors: Yung-Ho Alex Chuang, J. Joseph Armstrong, Vladimir Dribinski, John Fielden
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Patent number: 9620341Abstract: A system for inspecting a sample including a detector, either a photomultiplier tube or an electron-bombarded image sensor, that is positioned to receive light from the sample. The detector includes a semiconductor photocathode and a photodiode. Notably, the photodiode includes a p-doped semiconductor layer, an n-doped semiconductor layer formed on a first surface of the p-doped semiconductor layer to form a diode, and a pure boron layer formed on a second surface of the p-doped semiconductor layer. The semiconductor photocathode includes silicon, and further includes a pure boron coating on at least one surface.Type: GrantFiled: June 22, 2016Date of Patent: April 11, 2017Assignee: KLA-Tencor CorporationInventors: Yung-Ho Alex Chuang, David L. Brown, John Fielden
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Patent number: 9620547Abstract: A high sensitivity image sensor comprises an epitaxial layer of silicon that is intrinsic or lightly p doped (such as a doping level less than about 1013 cm?3). CMOS or CCD circuits are fabricated on the front-side of the epitaxial layer. Epitaxial p and n type layers are grown on the backside of the epitaxial layer. A pure boron layer is deposited on the n-type epitaxial layer. Some boron is driven a few nm into the n-type epitaxial layer from the backside during the boron deposition process. An anti-reflection coating may be applied to the pure boron layer. During operation of the sensor a negative bias voltage of several tens to a few hundred volts is applied to the boron layer to accelerate photo-electrons away from the backside surface and create additional electrons by an avalanche effect. Grounded p-wells protect active circuits as needed from the reversed biased epitaxial layer.Type: GrantFiled: July 1, 2016Date of Patent: April 11, 2017Assignee: KLA-Tencor CorporationInventors: Yung-Ho Alex Chuang, Jingjing Zhang, John Fielden
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Patent number: 9601299Abstract: A photocathode is formed on a monocrystalline silicon substrate having opposing illuminated (top) and output (bottom) surfaces. To prevent oxidation of the silicon, a thin (e.g., 1-5 nm) boron layer is disposed directly on the output surface using a process that minimizes oxidation and defects, and a low work-function material layer is then formed over the boron layer to enhance the emission of photoelectrons. The low work-function material includes an alkali metal (e.g., cesium) or an alkali metal oxide. An optional second boron layer is formed on the illuminated (top) surface, and an optional anti-reflective material layer is formed on the boron layer to enhance entry of photons into the silicon substrate. An optional external potential is generated between the opposing illuminated (top) and output (bottom) surfaces. The photocathode forms part of novel sensors and inspection systems.Type: GrantFiled: July 22, 2013Date of Patent: March 21, 2017Assignee: KLA-Tencor CorporationInventors: Yung-Ho Alex Chuang, John Fielden
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Publication number: 20170069455Abstract: A photocathode is formed on a monocrystalline silicon substrate having opposing illuminated (top) and output (bottom) surfaces. To prevent oxidation of the silicon, a thin (e.g., 1-5 nm) boron layer is disposed directly on the output surface using a process that minimizes oxidation and defects. An optional second boron layer is formed on the illuminated (top) surface, and an optional anti-reflective material layer is formed on the second boron layer to enhance entry of photons into the silicon substrate. An optional external potential is generated between the opposing illuminated (top) and output (bottom) surfaces. The photocathode forms part of novel electron-bombarded charge-coupled device (EBCCD) sensors and inspection systems.Type: ApplicationFiled: November 17, 2016Publication date: March 9, 2017Inventors: YUNG-HO ALEX CHUANG, JOHN FIELDEN
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Publication number: 20170048467Abstract: An inspection system and methods in which analog image data values (charges) captured by an image sensor are binned (combined) before or while being transmitted as output signals on the image sensor's output sensing nodes (floating diffusions), and in which an ADC is controlled to sequentially generate multiple corresponding digital image data values between each reset of the output sensing nodes. According to an output binning method, the image sensor is driven to sequentially transfer multiple charges onto the output sensing nodes between each reset, and the ADC is controlled to convert the incrementally increasing output signal after each charge is transferred onto the output sensing node. According to a multi-sampling method, multiple charges are vertically or horizontally binned (summed/combined) before being transferred onto the output sensing node, and the ADC samples each corresponding output signal multiple times. The output binning and multi-sampling methods may be combined.Type: ApplicationFiled: July 14, 2016Publication date: February 16, 2017Inventors: Yung-Ho Alex Chuang, David L. Brown, Devis Contarato, John Fielden, Daniel I. Kavaldjiev, Guoheng Zhao, Jehn-Huar Chern, Guowu Zheng, Donald W. Pettibone, Stephen Biellak
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Publication number: 20170047207Abstract: An electron source is formed on a silicon substrate having opposing first and second surfaces. At least one field emitter is prepared on the second surface of the silicon substrate to enhance the emission of electrons. To prevent oxidation of the silicon, a thin, contiguous boron layer is disposed directly on the output surface of the field emitter using a process that minimizes oxidation and defects. The field emitter can take various shapes such as pyramids and rounded whiskers. One or several optional gate layers may be placed at or slightly lower than the height of the field emitter tip in order to achieve fast and accurate control of the emission current and high emission currents. The field emitter can be p-type doped and configured to operate in a reverse bias mode or the field emitter can be n-type doped.Type: ApplicationFiled: August 11, 2016Publication date: February 16, 2017Inventors: Yung-Ho Alex Chuang, Yinying Xiao-Li, Xuefeng Liu, John Fielden