• Journal of the Semiconductor & Display Technology
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• v.23 no.1
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• pp.52-55
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• 2024

In this paper, a state change study was conducted through Frequency Domain Reflectometry (FDR) technology for the process chamber of plasma equipment for semiconductor manufacturing. In the experiment, by direct connecting the network analyzer to the RF matcher input of the 300 mm plasma enhanced chemical vapor deposition (PECVD) chamber, S11 was measured in a situation where plasma was not applied, and the frequency domain reacting to the chamber state change was searched. Response factors to changes in the status, such as temperature, spacing of the heating chuck, internal pressure difference, and process gas supply state were confirmed. Through this, the frequency domain in which a change in the reflection value was detected through repeated experiments. The reliability of the measured micro-displacement was verified through reproducibility experiments.

• Journal of the Semiconductor & Display Technology
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• v.22 no.2
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• pp.1-5
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• 2023

In the past, display devices have undergone many changes, such as plasma TVs and LCDs, and have continued to develop. Recently, new display technologies, such as Organic Light Emitting Diode displays and Inorganic Light Emitting Diode displays, have been developed. Among them, Micro LED displays have the potential to improve performance more than LCDs and OLEDs, but a lot of effort and time are needed until the mass production technology (transfer and bonding) of Micro LED displays is developed. We have developed a new Micro LED display light source that can be produced using existing transfer and bonding process technologies to enable faster commercialization of Micro LED in the industry. This light source is TFT deposition on LED. TFT deposition on LED has the advantage of being able to produce displays using existing process technology, making early commercialization of display application products possible. In this study, we applied the Active Driving method to verify the performance of TFT deposition on LED as a display to determine its commercialization potential. Additionally, to facilitate faster application of Micro LED in the industry, we applied TFT deposition on LED to Optical Wireless Communication systems, which are widely used in application service areas such as safety/security and sensors, to verify its communication performance. The experimental results confirmed that TFT deposition on LED is not only capable of AM driving but can also be applied to OWC systems.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.515-517
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• 2004

The laser absorption spectroscopy has been used for measuresurement of the xenon atoms in the resonant $1S_4$ and metastable $1S_5$ states in coplanar AC PDP. For the purpose of improving VUV luminous efficiency and optimization of PDP cells, it is important to study behavior of excited Xe atoms in a micro-discharge cell of a coplanar AC-PDP. We measured the xenon excited density of $1S_5$ and $1S_4$ state under mixture gas of Ne-Xe(10%) with gas pressure of 350 Torr and sustaining gap distance of 150 um.

• Transactions on Electrical and Electronic Materials
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• v.10 no.4
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• pp.111-115
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• 2009

We present a study on the reflection of optically controlled microwave pulses from non uniform plasma layers in semiconductors. The transient response of the microwave pulses in different plasma layers has been evaluated by means of the reflection function of dielectric microstrip lines. The lines were used with an open-ended termination containing an optically induced plasma region, which was illuminated by a light source. The reflection characteristics impedance resulting from the presence of plasma is evaluated by means of the equivalent transmission line model. We have analyzed the variation of the transient response in a 0.01 cm layer with a surface frequency in the region of 128 GHz. In the reflection the variation of the diffusion length $L_D$ is large compared with the absorption depth $1/{\alpha}_l$. The variation of the characteristic response of the plasma layer with differentially localized pulses has been evaluated analytically. The change of the reflection amplitude has been observed at depths of 0.1 cm, 0.01 cm and $0.1{\times}10^{-5}$ cm respectively.

• 연구논문집
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• s.25
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• pp.193-205
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• 1995

Plasma spray coating technology is essential for the microsemiconductor processes based on the electronic and computer industry, and extend gradually the range of application for up-to-date industry such as diesel engine and gas turbine components. These thechonoogies may be applied to the components requiring wear-resistance, heat resistance, fatigue-resistance, and corrosion-resistance. In this research, plasma spray technology was selected for the wear resistant coatings as the most proper technique. The final goal of this study is to improve the wear resistance through establishment of coating soft-ware, and basic research for industrialization of the technology concerned.

• Journal of the Korean Vacuum Society
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• v.17 no.6
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• pp.501-510
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• 2008

The stealth technology to conceal an aircraft from the vision of a radar have been accomplished by coating the surface with special paints absorbing the electromagnetic wave. Nowadays, researches to utilize characteristics of the plasma-wave interaction for realizing the stealth technology are actively progressed. In this paper, to investigate the physical feasibility of the plasma stealth, calculation results for the required conditions of the plasma cloaking on the aircraft flying in the air for showing the stealth function, using a flat non-magnetized non-uniform plasma model, are reported and discussed.

• Journal of the Korean Society of Visualization
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• v.19 no.3
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• pp.123-129
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• 2021

Many plants and animals in nature have superhydrophobic surfaces. This superhydrophobic surface has various properties such as self-cleaning, moisture collection, and anti-icing. In this study, the superhydrophobic properties of PTFE surface were treated by plasma etching. There were four important factors that changed the surface properties. Micro-sized protrusions were formed by plasma etching. The most influential parameter was RF Power. The contact angle of the pristine PTFE surface was about 113.8°. The maximum contact angle of the surface after plasma treatment with optimized parameters was about 168.1°. In this case, the sliding angle was quite small about 1°. These properties made it possible to remove droplets easily from the surface. To verify the self-cleaning effect of the surface, graphite was used to contaminate the surface and remove it with water droplets. Graphite particles were easily removed from the optimized surface compared to the pristine surface. As a result, a surface having water repellency and self-cleaning effects could be produced with optimized plasma etching parameters.

• Korean Journal of Materials Research
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• v.16 no.4
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• pp.225-230
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• 2006

Nanoimprint lithography (NIL) is a novel method of fabricating nanometer scale patterns. It is a simple process with low cost, high throughput and resolution. NIL creates patterns by mechanical deformation of an imprint resist and physical contact process. The imprint resist is typically a monomer or polymer formulation that is cured by heat or UV light during the imprinting process. Stiction between the resist and the stamp is resulted from this physical contact process. Stiction issue is more important in the stamps including narrow pattern size and wide area. Therefore, the antistiction layer coating is very effective to prevent this problem and ensure successful NIL. In this paper, an antistiction layer was deposited and characterized by PECVD (plasma enhanced chemical vapor deposition) method for metal stamps. Deposition rates of an antistiction layer on Si and Ni substrates were in proportion to deposited time and 3.4 nm/min and 2.5 nm/min, respectively. A 50 nm thick antistiction layer showed 90% relative transmittance at 365 nm wavelength. Contact angle result showed good hydrophobicity over 105 degree. $CF_2$ and $CF_3$ peaks were founded in ATR-FTIR analysis. The thicknesses and the contact angle of a 50 nm thick antistiction film were slightly changed during chemical resistance test using acetone and sulfuric acid. To evaluate the deposited antistiction layer, a 50 nm thick film was coated on a stainless steel stamp made by wet etching process. A PMMA substrate was successfully imprinting without pattern degradations by the stainless steel stamp with an antistiction layer. The test result shows that antistiction layer coating is very effective for NIL.

• Journal of the Korean Society of Food Science and Nutrition
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• v.1 no.1
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• pp.37-50
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• 1972

An analysis of the free amino acid contained in the plasma and erythrocytes of the six groups of Wistar Strain male adult rats(body weight 200-300g) having fasted for sixteen hours was made by means of the HITACHI Amino Acid Autoanalyzer and the result of which was corrected with RC-24 B TOMY Micro Hematocrit Centrifuge. There was a depression of the plasma and erythrocytes free amino acid level on the noprotein diet with ad libitum feeding. But on the 20% casein diet there was an elevation in the levels of free amino acid and consequently alanine, glysine, lysine, serine and arginine level in the erythrocytes and threonine glutamic acid and taurine level in the plasma increased on the high protein diet. There was more plasma and erythrocytes free amino acid level on the 5% casein-30% fat diet than on the 5% casein-no fat diet with pair-feeding. In comparison, on the low calorie diet more free amino acids were found in plasma than in erythrocytes, but on the higher calorie diet more free amino acids were found in the erythrocytes than in the plasma. On the 20% casein-30% fat diet with pair-feeding the erythrocytes free amino acids level increased but in plasma free amino acids level decreased. Such as an opposite result was given in plasma and erythrocytes free amino acids level. In the pair-fed four groups, erythrocytes per plasma generally increased in the rate of less than 10.0 as the calorie increased. The essential amino acid per non essential amino acid generally increased in the ratio as protein level and calorie increased, and that ratio range was from 0.2 to 0.7. And essential amino acid per non essential amino acid of plasma was higher than that of erythrocytes.

• Journal of the Korean Chemical Society
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• v.15 no.2
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• pp.69-84
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• 1971

An analysis of the free amino acid contained in the plasma and erythrocytes of the six groups of Wistar Strain male adult rats (body weight 200-300g) having fasted for sixteen hours was made by means of the HITACHI Amino Acid Autoanalyzer and the result of which was corrected with RC-24B TOMY Micro Hematocrit Centrifuge. There was a depression of the plasma and erythrocytes free amino acid level on the no-protein diet with ad libitum feeding. But on the 20% casein diet there was an elevation in the levels of free amino acid and consequently alanine, glysine, lysine, serine and arginine level in the erythrocytes and threonine, glutamic acid and taurine level in the plasma increased on the high protein diet. There was more plasma and erythrocytes free amino acid level on the 5% casein- 30% fat diet than on the 5% casein-no fat diet with pair-feeding. In comparison, on the low calorie diet more free amino acids were found in plasma than in erythrocytes, but on the higher calorie diet more free amino acids were found in the erythrocytes than in the plasma. On the 20% casein-30% fat diet with pair-feeding the erythrocytes free amino acids level increased but in plasma free amino acids level decreased. Such as an opposite result was given in plasma and erythrocytes free amino acids level. In the pair-fed four groups, erythrocytes per plasma generally increased in the rate of less than 10.0 as the calorie increased. The essential amino acid per non essential amino acid generally increased in the ratio as protein level and calorie increased, and that ratio range was from 0.2 to 0.7. And essential amino acid per non essential amino acid of plasma was higher than that of erythrocytes.