Snu Precision Co., Ltd.

Other

Seoul National University

Heui Jae Pahk

Seong Ryong Kim

Seung Woo Lee

Sung Wook Cho

Woo Jung Ahn

Heung Hyun Shin

Suk Won Lee

Sang Soo Kang

Young Min Hwang

Jun Hyeok Lee

Chong Nam Chu

Joon Hee Moon

Tae Yong Jo

Ki Hun Lee

Min Gyu Kim

System for measuring the thickness and properties of a thin film using a spatial light modulator according to the inventive concept includes: a spatial light modulator; a first beam splitter; an objective lens; a second beam splitter; a first camera configured to acquire a surface image of the sample; an optical fiber equipped with a light receiving unit to receive reflected light passing through a certain area of a back focal plane of the objective lens; and a spectrometer configured to measure an intensity of light received from the optical fiber and output the measured intensity as an electrical signal.

System for measuring thickness and physical properties of thin film using spatial light modulator

Provided herein is a three-dimensional shape measurement apparatus capable of measuring a shape of a measurement object using an interferometer and color information of the measurement object, the apparatus including a light source for emitting a light; a light divider for reflecting the light emitted from the light source or transmitting a light reflected by the measurement object; a lens unit for focusing the light reflected by the light divider onto the measurement object; a light detector for detecting the light reflected from the measurement object; and a light adjuster arranged on a light path between the light source and the light divider, and configured to interrupt the light being emitted from a central area of the light source to reduce interference of light occurring in the lens unit.

Three-dimensional shape measuring device capable of measuring color information

Disclosed is a method of measuring thickness or a surface profile of a thin film layer formed on a base layer through a white light scanning interferometry, the method including: preparing simulation interference signals corresponding to thicknesses by assuming a plurality of sample thin film layers different in thickness from one another and simulating interference signals with respect to the respective sample thin film layers; acquiring a real interference signal with respect to an optical-axis direction of entering the thin film layer by illuminating the thin film layer with white light; preparing a plurality of estimated thicknesses that the thin film layer may have on the basis of the real interference signal; comparing whether the simulation interference signal having thickness corresponding to the estimated thickness is substantially matched with the real interference signal; and determining the thickness of the simulation interference signal substantially matched with the real interference signal as the thickness of the thin film layer.

Estimating thickness based on number of peaks between two peaks in scanning white light interferometry

Provided herein is a TSV measuring interferometer that uses a variable field stop that adjusts such that a light is focused at an inlet and at a bottom surface of a TSV when measuring a diameter and depth of the TSV, thereby reducing a measurement time and result data, the interferometer also using a telecentric lens that adjusts the light injected into the TSV to be a straight line, so as to obtain a sufficient amount of light reaching the bottom surface to improve the accuracy of measurement even in a TSV having a large aspect ratio.

Interferometer for TSV measurement and measurement method using same

A measurement and compensation system for thermal errors in a machine tool is disclosed. A module is provided to compensate thermal errors of the machine tool. The module comprises an operating part, a data bank, an analog to digital converter, a counter and a digital input/output part. The data bank stores in all the coefficients applied to a thermal error modeling equation which governs a relation between temperatures and thermal errors at various operating conditions. The operating part determines all the coefficients of the thermal error modeling equation which are stored in the data bank and calculates the thermal errors corresponding to the temperatures of a plurality of the thermocouples by the temperatures of a plurality of thermocouples inputted from the A/D converter and the positional coordinates of the bed inputted from the counter. Then, digital data of the calculated thermal errors are inputted into the digital input/output part and the digital input/output part converts the digital data to digital signal to input the digital signals into the controller. A controller orders the machine tool to compensate the thermal errors at the positional coordinates of the bed and the feed of the spindle. Accordingly, since the machine tool compensates the thermal errors in advance, the machine tool processes precisely workpieces in spite of the occurrence of the thermal errors.

Measurement and compensation system for thermal errors in machine tools

A non-contacting measuring method for three dimensional micro pattern in a measuring object is disclosed. Three dimensional micro pattern of the surface of the measuring object is measured using blur of light. For measurement, a mechanism of an optical window with a slit is inserted between light source and the measuring object. The blurred image is captured by charge coupled device sensor based image frame grabber, and is analyzed in personal computers. All the values of the relative height differences are obtained in overall scanning measurement area of the measuring object. The relative height differences are the distances from the reference position to the other positions. The reference position is selected when its image is sharp in focus on the screen. At this time, images of the other positions except the reference position are blurred out of focus on the screen. Also, from the law of geometric optics and the geometric similarity of triangles, the relation equation between the height difference and the ratio of blurred image size to sharp image size can be constructed. When the size of the image of the reference position and the sizes of the images with the blurred image of the other positions are measured, all the height differences between the reference position and the other position can be calculated if the coefficients of the relation equation are evaluated.

Non contact measuring method for three dimensional micro pattern in

A method of assessing three-dimensional volumetric errors of multiaxis machine tools in three-dimensional working space is disclosed. Each three-dimensional volumetric error component can be systematically measured and analyzed on the modeling of polynominal functions in accordance with the volumetric errors and the kinematic chain in accordence with the corresponding machine tool. The method inputs the measured radial data performed on the three orthogonal planes, analyzing the parametric errors such as positional, straightness, angular, squareness, and backlash errors. The positional error components along each of three orthogonal axes are modeled as a dimensionless polynominal function with corresponding positional error coefficients. The method also can assess dynamic performance of the machine tools such errors due to the servo gain mismatch. The method employs the kinematic ball bar to assess the volumetric errors.

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Seoul, South Korea

Heui Jae Pahk