• Journal of Korean Institute of Industrial Engineers
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• v.41 no.6
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• pp.572-578
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• 2015

Yield prediction is one of the most important issues in semiconductor manufacturing. Especially, for a fast-changing environment of the semiconductor industry, accurate and reliable prediction techniques are required. In this study, we propose a prediction model to predict wafer yield based on virtual metrology process parameters in semiconductor manufacturing. The proposed prediction model addresses imbalance problems frequently encountered in semiconductor processes so as to construct reliable prediction model. The effectiveness and applicability of the proposed procedure was demonstrated through a real data from a leading semiconductor industry in South Korea.

• Journal of Sensor Science and Technology
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• v.18 no.4
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• pp.322-326
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• 2009

To estimate the measurement uncertainty for industrial platinum resistance thermometers(IPRTs) made with 3-wire connection, the immersion temperature profile was investigated using a liquid bath. Two types of IPRTs having lead wires made of silver and nickel were constructed and the immersion profiles were measured at temperatures from -50 $^{\circ}C$ to 250 $^{\circ}C$ using 3-wire and 4-wire method. As immersion depth and temperature increased, the resistances measured by 3-wire method increased linearly but not for 4-wire method. To calibrate a 3-wire IPRT, the immersion effect must be accounted for. We propose a linear equation to assess correctly the measurement uncertainty.

• 한국초전도학회:학술대회논문집
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• 2009.07a
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• pp.37-37
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• 2009

• Progress in Superconductivity
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• v.4 no.1
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• pp.59-63
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• 2002

10-V Josephson junction array arranged in 8 parallel stripline paths was fabricated using self-aligning and reactive ion etching techniques. These techniques were introduced in detail with aim of obtaining high-quality junctions. The array has 18,184 Josephson junctions with the area of $12\mu\textrm{m}$$\times$$38\mu\textrm{m}$. The gap voltage and minimum critical current density were about 2.7 ㎷ and ／$23 A\textrm{cm}^2$, respectively. And the critical current density and leakage current at 5 volt were about 27 $A／\textrm{cm}^2$ and $5\mu\textrm{A}$, respectively When operated in the frequency range of 76-88 ㎓, the away generated constant voltage steps up to 14-19 V. The step size near 10-V was more than 7 $\mu\textrm{A}$.

• Progress in Superconductivity
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• v.4 no.1
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• pp.64-67
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• 2002

The attenuation of millimeter waves (70-100 ㎓) propagating along Josephson Junction stripline had been measured by pattern recognition near gap voltage and proximity current bump. Test series arrays of 2000, 3000, and 4000 Josephson junctions with the area of $12\mu\textrm{m}$$\times$ $38\mu\textrm{m}$ had two sub-arrays with 50 Junctions at both ends. The arrays were fabricated with and without applying a plasma nitridation process to Nb ground plane. The effects of a nitridationprocess measured by the pattern recognition near gap voltage and proximity current bump were about 1.3-1.7 ㏈ and 1.6-1.8 ㏈, respectively. This means that the last sub-arrays with a nitridation process receive 26-34% more power than those without a nitridation process.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.792-793
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• 2006

In the paper, the influence of different particle size $D:D>125{\mu}m$, $D<50{\mu}m$ and between on magnetic properties of a standardized dielectromagnetic is presented. The tests were taken at frequencies of between 50Hz, and 500Hz. Presented in the paper results provide important materials property data to allow the selection of the most appropriate dielectromagnetic particle size for different applications.

• Journal of the Optical Society of Korea
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• v.20 no.6
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• pp.733-738
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• 2016

We calculate optical properties of guided modes of a hybrid-guiding photonic crystal fiber. The design and modeling of such hybrid-guiding PCF is made by replacing air holes with inserts of high refractive index material layer by layer in order. The optical properties such as mode intensity profile, mode dispersion, optical birefringence, confinement loss, and chromatic dispersion during transition of the guiding mechanism are analyzed and discussed. The guided modes in the hybrid-guiding region are also compared with those of reference index-guiding and bandgap-guiding photonic crystal fibers.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.6
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• pp.96-104
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• 2007

Calibration of the spring constants of atomic force microscopy (AFM) cantilevers is one of the issues in biomechanics and nanomechanies for quantified force metrology at pieo- or nano Newton level. In this paper, we present an AFM cantilever calibration system: the Nano Force Calibrator (NFC), which consists of a precision balance and a one-dimensional stage. Three types of AFM cantilevers (contact and tapping mode) with different shapes (beam and V) and spring constants (42, 1, 0.06 N $m^{-1}$) are investigated using the NFC. The calibration results show that the NFC can calibrate the micro cantilevers ranging from 0.01 ${\sim}$ 100 N $m^{-1}$ with relative uncertainties of less than 2%.

• Journal of the Korean Society of Safety
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• v.17 no.4
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• pp.11-18
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• 2002

We proposed a new experimental method which is required to easily observe the growth behavior of fatigue cracks. In the proposed method, the image data of cracks were stored into the computer while the cyclic loading was interrupted. After testing, crack length was determined using an image processing software which was developed by authors. By comparing the data measured by the image processing system with those by the manual measurement with a microscope, the effectiveness of the image processing system was established. If the proposed method is used to monitor and observe the crack growth behavior automatically, the time and efforts for fatigue test could be dramatically reduced.

• Journal of Sensor Science and Technology
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• v.17 no.6
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• pp.429-436
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• 2008

A system is designed and fabricated for the automatic low temperature calibration by comparison of industrial resistance thermometers. The cryostat is suitable for the calibration of four capsule type thermometers and four long stem thermometers. By the automatic temperature control of the cryostat, we could calibrate thermometers from $-200^{\circ}C$ to $0^{\circ}C$ for ${\sim}15$ hours by one fill of liquid nitrogen in the test run of the system. The uncertainty of the calibration for industrial platinum resistance thermometers using the automatic system is about 30mK with a 95.% confidence interval.