• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.12
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• pp.58-66
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• 1999

In this paper, an advanced histogram equalization algorithm for contrast enhancement is presented. Histogram equalization is the most popular algorithm. Global histogram equalization is simple and fast, but its contrast enhancement power is relatively low. Local histogram equalization, on the other hand, can enhance overall contrast more effectively, but the complexity of computation required is very high. In this paper, a low pass filter type mask is used to get a sub-block histogram equalization function to more simply produce the high contrast. The low pass filter type mask is realized by partially overlapped sub-block histogram equalization (POSHE). With the proposed method. the computation overhead is reduced by a factor of about one hundred compared to that of local histogram equalization while still achieving high contrast.

• Applied Chemistry for Engineering
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• v.17 no.3
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• pp.327-330
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• 2006

We investigated the usefulness of $NbO_{x}$ nanopillars as an etching mask of dry etching for the formation of Si nanodot arrays. The $NbO_{x}$ nanopillar arrays were prepared by the anodic aluminum oxidation process of Al and Nb thin films. The etch rate and etch profile of $NbO_{x}$ nanopillar arrays were examined by varying the experimental conditions such as the concentration of etch gas, coil rf power, and dc bias voltage in the reactive ion etch system using the inductively coupled plasma. As the concentration of $Cl_{2}$ gas increased, the etch rate of $NbO_{x}$nanopillars decreased. With increasing coil rf power and dc bias voltage, the etch rates were found to increase. The etch characteristics and etch mechanism of $NbO_{x}$ nanopillars were investigated by varying the etch time under the selected etch conditions.

• Journal of the Korean Society of Safety
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• v.21 no.2 s.74
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• pp.35-45
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• 2006

Cobalt catalysts for gas mask loaded on various supports such as $Al_{2}O_{3},\;TiO_{2}$, AC(activated carbon) and $SiO_{2}$ were used to examine influences of calcination temperatures and reaction temperatures for CO oxidation. $Co(NO_{3})_2{\cdot}6H_{2}O$ was used as cobalt precursor and the catalysts were prepared by incipient wetness impregnation. The catalysts were characterized using XRD, TGA/DTA, TEM, $N_{2}$ sorption, and XPS. For the catalytic activity, support was in the order of ${\gamma}-Al_{2}O_{3}>TiO_{2}>SiO_{2}>AC\;and\;Al_{2}O_{3}$. The catalytic activity at lower temperature than $80^{\circ}C$ showed that with the increase of reaction temperature, cobalt catalysts on ${\gamma}-Al_{2}O_{3},\;TiO_{2},\;AC\$ has the negative activation energy but that of $SiO_{2}$ was positive.

• Journal of the Semiconductor & Display Technology
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• v.22 no.4
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• pp.7-12
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• 2023

The edge ring placed on the outside of the electrostatic chuck (ESC) is a key component for protecting the ESC and controlling the etching uniformity of the edge of the wafer. Therefore, it is very important to understand the etching phenomenon of edge rings for edge ring management and equipment homeostasis. In this study, a specimen with SiO₂ hard mask and underlying Si mold was installed on the edge ring surface and the etching results were measured by varying the edge ring 2MHz RF power. By developing PI-VM model with high prediction accuracy and analyzing the roles of key parameters in the model, we were able to evaluate the effect of plasma and sheath characteristics around the edge ring on edge ring erosion. This analysis method provided information necessary for edge ring maintenance and operation.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.332-332
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• 2015

Block Copolymer lithography는 deep nano-scale device 제작을 위한 기존의 top-down방식의 photo-lithography를 대체할만한 기술로 많은 연구가 진행되고 있다. polystyrene(PS)/poly-methyl methacrylate (PMMA)로 구성된 BCP의 nano-scale PS mask는 일반적인 플라즈마 공정에 쉽게 damage를 입는다. 중성빔 식각을 이용하여 식각 공정 중 발생하는 BCP의 degradation을 감소시키고, 비등방성 식각 profile을 얻을 수 있으며 sidewall roughness(SWR)와 sidewall angle(SWA)가 향상되는 것을 알 수 있었다.

• Proceedings of the IEEK Conference
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• 2002.06b
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• pp.209-212
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• 2002

As the mask design rules get smaller, the probability of the process failure becomes higher doc to the narrow overlay margin between the contact and metal interconnect layers. To obtain the minimum process margin, a tabbing and cutting method Is applied with the rule based optical\ulcorner proximity correction to the metal layer, so that the protection to bridge problems caused by the insufficient space margin between the metal layers can be accomplished. The side-lobe phenomenon from the attenuated phase shift mask with the tight design rule is analyzed through the aerial image simulation for test patterns with variation of the process parameters such as numerical aperture, transmission rate, and partial coherence. The corrected patterns are finally generated by the rules extracted from the side-lobe simulation.

• Transactions on Electrical and Electronic Materials
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• v.11 no.5
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• pp.202-205
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• 2010

In this study, the etch properties of $Al_2O_3$ thin films deposited by atomic layer deposition were investigated as a function of the $O_2$ content in $BCl_3$/Ar inductively coupled plasma. The experiments were performed by comparing the etch rates and selectivity of $Al_2O_3$ over the hard mask materials as functions of the input plasma parameters, such as the gas mixing ratio, DC-bias voltage, ratio-frequency (RF) power and process pressure. The highest obtained etch rate was 477 nm/min at an RF power of 700 W, $O_2$ to $BCl_3$/Ar gas ratio of 15%, DC-bias voltage of -100 V and process pressure of 15 mTorr. The deposition occurred on the surfaces when the amount of $O_2$ added to the $BCl_3$/Ar gas was too high at a low DC-bias voltage or high process pressure. X-ray photoelectron spectroscopy was used to investigate the chemical reactions on the etched surface.

• 전기의세계
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• v.27 no.4
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• pp.45-51
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• 1978

A new method of realizing the field effect transistor with a sub-.mu. channel width is described. The sub-.mu. channel width is made possible by etching grooves into n$^{+}$ pn$^{[-10]}$ n$^{[-10]}$ structure and using p region at the wall for the channel region of the Metal-Oxide-Semiconductor transistor (MOST), or by diffusing two different types of impurities through the same diffusion mask and using p region at the surface for the channel region of MOST. When the drain voltage is increased at the pn$^{[-10]}$ drainjunction the depletion layer extends into the n$^{[-10]}$ region instead of into p region; this is also the secret of success to realize the sub-.mu. channel width. As the result of the experimental fabrication, a microwave MOST was obtained. The cut-off frequency was calculated to be 15.4 GHz by Linvill's power equation using the measured capacitances and transconductance.

• Journal of the Institute of Convergence Signal Processing
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• v.13 no.2
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• pp.63-69
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• 2012

Noise is regarded as an unwanted component of the image because it significantly reduces image quality. And image is often corrupted by mixed noise. In this paper an efficient modified weighted filter algorithm which combines spatial weight and intensity weight is proposed for removing mixed noise. In the proposed method, the filtering mask is separated into the four sub-windows and the parameters of the weights are confirmed by calculating local standard deviation and the mean of four sub-windows' standard deviations. Considering the spatial information and intensity information, the proposed method has good performance on not only noise elimination but also preservation of details. Simulation results demonstrate that the proposed method performs better than conventional algorithms.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.3
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• pp.1-5
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• 2000

Inductively coupled plasma (ICP) excited by a spiral planar antenna is used to etch elctrodes for PZT capacitors. Pt/RuO$_{2}$ bilayers are tested as bottom electrodes for PZT capacitors in order to utilize better leakage characteristics of Pt and easy etch characteristics of RuO$_{2}$ at the same time. The etch rates and selectivities to SiO$_{2}$ hard mask have been measured for each of Pt and RuO$_{2}$ in terms of various plasma conditions. As Cl$_{2}$ ratio increases in $O_{2}$/Cl$_{2}$ mixture, the etch rate of Pt increases while that of RuO$_{2}$ reaches the highest near 10 ％ of Cl$_{2}$. Optimum gas mixture ratio has been determined for etching Pt and RuO$_{2}$ bilayers sequentially, and sub-half micron patterning is demonstrated.