Patents by Inventor Chu-shik Kang
Chu-shik Kang 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: 9921051Abstract: Provided are a thickness measuring apparatus and a thickness measuring method. The thickness measuring method includes irradiating a first laser beam of a first wavelength ?1 to a transparent substrate and measuring intensity of the first laser beam transmitting through the transparent substrate; irradiating a second laser beam of a second wavelength ?2 to the transparent substrate and measuring intensity of the second laser beam transmitting through the transparent substrate; and extracting a rotation angle on a Lissajous graph using the first and second laser beams transmitting through the transparent substrate. A phase difference between adjacent rays by multiple internal reflection of the first laser beam and a phase difference between adjacent rays by multiple internal reflection of the second laser beam is maintained at ?/2.Type: GrantFiled: July 3, 2014Date of Patent: March 20, 2018Assignee: Korea Research Institute of Standards and ScienceInventors: Jae-Wan Kim, Jong-Ahn Kim, Chu-Shik Kang, Jong-Han Jin
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Patent number: 9651403Abstract: Provided are an absolute position measurement method, an absolute position measurement apparatus, and a scale. The scale includes a scale pattern formed by replacing repeatedly arranged pseudo-random-codes with a sequence of a linear feedback shift register of N stages using a first symbol with first width representing a first state and a second symbol with second width representing a second state. The first is divided into two or more first symbol areas of different structures, and the second symbol is divided into two or more second symbol areas of different structures. There is at least one overlap area in which the first symbol and the second symbol overlap each other to have the same structure.Type: GrantFiled: November 13, 2014Date of Patent: May 16, 2017Assignee: Korea Research Institute of Standards and ScienceInventors: Jong-Ahn Kim, Jae-Wan Kim, Tae-Bong Eom, Chu-Shik Kang, Jong-Han Jin
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Patent number: 9121696Abstract: The present invention pertains to a device and a method for measuring a via hole of a silicon wafer, wherein it is possible to precisely measure the depth of the via hole without damaging the wafer. Broadband infrared light is radiated to a silicon wafer which has a superior light transmission property, so that the depth of the via hole may be measured from the light which is reflected from each boundary surface of the wafer and the interference signal of reference light. The via hole measuring device according to the present invention includes: a light source unit for generating broadband infrared light; and an interferometer for radiating the light generated from the light source unit to a silicon wafer, so as to measure the depth of a via hole formed on the wafer according to the spectrum period of the interference signal of the light, which is reflected from the silicon wafer.Type: GrantFiled: June 24, 2011Date of Patent: September 1, 2015Assignee: KOREA RESEARCH INSTITUTE OF STANDARDS AND SCIENCEInventors: Jong Han Jin, Jae Wan Kim, Jong Ahn Kim, Chu-Shik Kang
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Publication number: 20150069225Abstract: Provided are an absolute position measurement method, an absolute position measurement apparatus, and a scale. The scale includes a scale pattern formed by replacing repeatedly arranged pseudo-random-codes with a sequence of a linear feedback shift register of N stages using a first symbol with first width representing a first state and a second symbol with second width representing a second state. The first is divided into two or more first symbol areas of different structures, and the second symbol is divided into two or more second symbol areas of different structures. There is at least one overlap area in which the first symbol and the second symbol overlap each other to have the same structure.Type: ApplicationFiled: November 13, 2014Publication date: March 12, 2015Inventors: Jong-Ahn Kim, Jae-Wan Kim, Tae-Bong Eom, Chu-Shik Kang, Jong-Han JIN
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Publication number: 20150012246Abstract: Provided are a thickness measuring apparatus and a thickness measuring method. The thickness measuring method includes irradiating first laser beam of a first wavelength ?1 to a transparent substrate and measuring intensity of first laser beam transmitting the transparent substrate; irradiating second laser beam of a second wavelength ?2 to the transparent substrate and measuring intensity of second laser beam transmitting the transparent substrate; and extracting a rotation angle on a Lissajous graph using the first and second laser beams transmitting the transparent substrate. A phase difference between adjacent rays by multiple internal reflection of the first laser beam and a phase difference between adjacent ray by multiple internal reflection of the second laser beam is maintained at ?/2.Type: ApplicationFiled: July 3, 2014Publication date: January 8, 2015Inventors: Jae-Wan KIM, Jong-Ahn KIM, Chu-Shik KANG, Jong-Han JIN
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Publication number: 20150009509Abstract: Provided are a transparent substrate monitoring apparatus and a transparent substrate monitoring method. The transparent substrate monitoring apparatus includes a light emitting unit emitting light; a double slit disposed on a plane defined in a first direction and a second direction intersecting a propagation direction of incident light and includes a first slit and a second slit spaced apart from each other in the first direction to allow the light to pass therethrough; an optical detection unit measuring an intensity profile or position of an interference pattern formed on a screen plane; and a signal processing unit receiving a signal from the optical detection unit to calculate an optical phase difference or an optical path difference.Type: ApplicationFiled: September 19, 2014Publication date: January 8, 2015Inventors: Jae-Wan KIM, Jong-Ahn KIM, Jong-Han JIN, Chu-Shik KANG, Tae-Bong EOM
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Publication number: 20130206992Abstract: The present invention pertains to a device and a method for measuring a via hole of a silicon wafer, wherein it is possible to precisely measure the depth of the via hole without damaging the wafer. Broadband infrared light is radiated to a silicon wafer which has a superior light transmission property, so that the depth of the via hole may be measured from the light which is reflected from each boundary surface of the wafer and the interference signal of reference light. The via hole measuring device according to the present invention includes: a light source unit for generating broadband infrared light; and an interferometer for radiating the light generated from the light source unit to a silicon wafer, so as to measure the depth of a via hole formed on the wafer according to the spectrum period of the interference signal of the light, which is reflected from the silicon wafer.Type: ApplicationFiled: June 24, 2011Publication date: August 15, 2013Applicant: KOREA RESEARCH INSTITUTE OF STANDARDS AND SCIENCEInventors: Jong Han Jin, Jae Wan Kim, Jong Ahn Kim, Chu-Shik Kang
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Patent number: 8290007Abstract: A frequency-stabilized laser apparatus and a method for stabilizing the frequency of a laser are disclosed. A semiconductor laser emits a beam. An external reflector has a resonance frequency and feeds back the emitted beam to the semiconductor laser if the frequency of the emitted beam is equal to the resonance frequency. An interference signal generator generates an interference signal for detecting the wavelength of the emitted beam and a controller detects the wavelength of the beam from the generated interference signal. According to the frequency-stabilized laser apparatus and the method for stabilizing the frequency of the laser, it is possible to stabilize the frequency of the beam emitted from the semiconductor laser and output the beam having the stable frequency for a long period of time.Type: GrantFiled: August 19, 2008Date of Patent: October 16, 2012Assignee: Korea Research Institute of Standards and ScienceInventors: Jae-Wan Kim, Tae-Bong Eom, Jong-Ahn Kim, Chu-Shik Kang
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Patent number: 8279448Abstract: A shape measurement apparatus and method using a laser interferometer are disclosed. The shape measurement apparatus includes a plurality of laser devices, which generate beams, emit a beam of a specific frequency from among the generated beams, and output interference signals for detecting wavelengths of the generated beams, and a controller for detecting the wavelengths of the generated beams from the outputted interference signals, and controlling the laser devices on the basis of the detected wavelengths. The optical unit projects the beam of the laser device on a target object, and generates an interference pattern of the object. Several shutters are closed and opened. If the shutters are closed, they prevent the beam of each laser device to be projected on the optical unit. An image pickup unit captures the interference pattern.Type: GrantFiled: August 19, 2008Date of Patent: October 2, 2012Assignee: Korea Research Institute of Standards and ScienceInventors: Jae-wan Kim, Tae-bong Eom, Jong-ahn Kim, Chu-shik Kang
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Publication number: 20100182614Abstract: A shape measurement apparatus and method using a laser interferometer are disclosed. The shape measurement apparatus includes a plurality of laser devices, which generate beams, emit a beam of a specific frequency from among the generated beams, and output interference signals for detecting wavelengths of the generated beams, and a controller for detecting the wavelengths of the generated beams from the outputted interference signals, and controlling the laser devices on the basis of the detected wavelengths. The optical unit projects the beam of the laser device on a target object, and generates an interference pattern of the object. Several shutters are closed and opened. If the shutters are closed, they prevent the beam of each laser device to be projected on the optical unit. An image pickup unit captures the interference pattern.Type: ApplicationFiled: August 19, 2008Publication date: July 22, 2010Applicant: KOREA RESEARCH INSTITUTE OF STANDARDS AND SCIENCEInventors: Jae-wan Kim, Tae-bong Eom, Jong-ahn Kim, Chu-shik Kang
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Publication number: 20100177795Abstract: A frequency-stabilized laser apparatus and a method for stabilizing the frequency of a laser are disclosed. A semiconductor laser emits a beam. An external reflector has a resonance frequency and feeds back the emitted beam to the semiconductor laser if the frequency of the emitted beam is equal to the resonance frequency. An interference signal generator generates an interference signal for detecting the wavelength of the emitted beam and a controller detects the wavelength of the beam from the generated interference signal. According to the frequency-stabilized laser apparatus and the method for stabilizing the frequency of the laser, it is possible to stabilize the frequency of the beam emitted from the semiconductor laser and output the beam having the stable frequency for a long period of time.Type: ApplicationFiled: August 19, 2008Publication date: July 15, 2010Applicant: KOREA RESEARCH INSTITUTE OF STANDARDS AND SCIENCEInventors: Jae-Wan Kim, Tae-Bong Eom, Jong-Ahn Kim, Chu-Shik Kang