• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.29 no.3
• /
• pp.168-174
• /
• 2016

A conductive oxide-based sapphire glass indium tin oxide/metal electrode and the optical coating, through patterning process was studied in excellent optical properties and integrated touch panel has a high strength. Indium tin oxide conductive oxides of the sapphire glass to 0.3 A at DC magnetron sputtering method of 10 min, gas flow Ar 10 Sccm Ar, $O_2$ 1.0 Sccm the formation conditions of the thin film after annealing at $550^{\circ}C$ for 30min was achieved through a 86% transmittance. In addition, the coating 130 nm hollow silica sol-gel was to improve the optical transmittance of the indium tin oxide to 91%. For the measurement by the modeling hollow silica sol by Macleod simulation and calculated the average values of silica part to the presence or absence in analogy to actual. Refractive index value and the actual value of the material on the simulation the transmittance difference is it does not completely match the air region similar to the actual value (transmission) could be confirmed that the measurement is set to a value of between 5 nm and 10 nm.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2010.11a
• /
• pp.235-240
• /
• 2010

Transpiration cooling is the most effective cooling technique for liquid rocket and air-breathing engines operating in aggressive environments with higher pressures and temperatures. Combustor liners and turbine vanes are cooled by the coolant(air or fuel) passing through their porous walls and also the exit coolant acting as an insulating film. However, its practical implementation has been hampered by the limitations of available porous materials. The search for more practical methods of increasing the internal heat transfer within the walls has led to the development of multi-laminate porous structures, such as Lamilloy$^{(R)}$ and Transply$^{(R)}$. This paper reviews recent research activities of transpiration cooling for the propulsions of liquid rocket, gas turbine, and scramjet.

• Journal of the Microelectronics and Packaging Society
• /
• v.26 no.4
• /
• pp.113-118
• /
• 2019

In this study, we investigated the growth of single-crystallinity α-Ga₂O₃ thin films on c-plane sapphire substrates using halide vapor pressure epitaxy. We also found the optimal growth conditions to suppress the phase transition of α-Ga₂O₃. Our results confirmed that the growth temperature and partial pressure of the reactive gas greatly influenced the crystallinity. The optimal growth temperature range was about 460~510℃, and the α-Ga₂O₃ thin films with the highest crystallinity were obtained at a III/VI ratio of 4. The thickness and surface morphology of the thin films was observed by scanning electron microscopy. The film thickness was 6.938 ㎛, and the full width at half maximum of the ω-2θ scan rocking curve was as small as 178 arcsec. The optical band gap energy obtained was 5.21 eV, and the films were almost completely transparent in the near-ultraviolet and visible regions. The etch pit density was found to be as low as about 6.0 × 10⁴ cm^-2.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2009.05a
• /
• pp.22.2-22.2
• /
• 2009

Currently, metal silicides become increasingly more essential part as a contact material in complimentary metal-oxide-semiconductor (CMOS). Among various silicides, NiSi has several advantages such as low resistivity against narrow line width and low Si consumption. Generally, metal silicides are formed through physical vapor deposition (PVD) of metal film, followed by annealing. Nanoscale devices require formation of contact in the inside of deep contact holes, especially for memory device. However, PVD may suffer from poor conformality in deep contact holes. Therefore, Atomic layer deposition (ALD) can be a promising method since it can produce thin films with excellent conformality and atomic scale thickness controllability through the self-saturated surface reaction. In this study, Ni thin films were deposited by thermal ALD using bis(dimethylamino-2-methyl-2-butoxo)nickel [Ni(dmamb)2] as a precursor and NH3 gas as a reactant. The Ni ALD produced pure metallic Ni films with low resistivity of 25 $\mu{\Omega}cm$. In addition, it showed the excellent conformality in nanoscale contact holes as well as on Si nanowires. Meanwhile, the Ni ALD was applied to area-selective ALD using octadecyltrichlorosilane (OTS) self-assembled monolayer as a blocking layer. Due to the differences of the nucleation on OTS modified surfaces toward ALD reaction, ALD Ni films were selectively deposited on un-coated OTS region, producing 3 ${\mu}m$-width Ni line patterns without expensive patterning process.

• Korean Journal of Materials Research
• /
• v.24 no.1
• /
• pp.60-65
• /
• 2014

Fe-based amorphous coatings were fabricated on a soda-lime glass substrate by the vacuum kinetic spray method. The effect of the gas flow rate, which determines particle velocity, on the deposition behavior of the particle and microstructure of the resultant films was investigated. The as-fabricated microstructure of the film was studied by field emission scanning electron microscopy (FE-SEM) and high resolution transmission electron microscopy (HR-TEM). Although the activation energy for transformation from the amorphous phase to crystalline phase was lowered by severe plastic deformation and particle fracturing under a high strain rate, the crystalline phases could not be found in the coating layer. Incompletely fractured and small fragments 100~300 nm in size, which are smaller than initial feedstock material, were found on the coating surface and inside of the coating. Also, some pores and voids occurred between particle-particle interfaces. In the case of brittle Fe-based amorphous alloy, particles fail in fragmentation fracture mode through initiation and propagation of the numerous small cracks rather than shear fracture mode under compressive stress. It could be deduced that amorphous alloy underwent particle fracturing in a vacuum kinetic spray process. Also, it is considered that surface energy caused by the formation of new surfaces and friction energy contributed to the bonding of fragments.

• Food Science and Preservation
• /
• v.10 no.2
• /
• pp.131-135
• /
• 2003

Bell pepper was packed with several plastic films, and investigated the quality Characteristics such as gas composition, weight loss, microbial load, soluble solid content, ascorbic acid and color during storage at 10$^{\circ}C$. Cast polypropylene (CPP), low density Polyethylene (LDPE), Polyolefin (MPD, PD961) and linear low density polyethylene (LLDPE) were used for this purpose. Oxygen concentration inside packages generally showed a 10∼14% after 1∼2 weeks, but package with CPP maintained above 15％ throughout the storage. Carbon dioxide concentration of CPP was above 2%, but other treatments showed below 2%. Weight loss of all treatments was below 3.0% after 5 weeks. Total microbial count showed a similar pattern compared to yeast and mold, and CPP maintained the highest microbial load after 3 weeks. Yellowness (b value) of bell pepper was generally increased throughout the storage, and MPD and PD961 were higher than other treatments.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.41 no.8
• /
• pp.521-529
• /
• 2017

Three-dimensional flow characteristics within a high-acceleration first-stage turbine vane passage has been investigated in a newly-built vane cascade for propulsion. The result shows that there is a strong favorable pressure gradient on the vane pressure surface. On its suction surface, however, there exists not only a much stronger favorable pressure gradient than that on the pressure surface upstream of the mid-chord but also a subsequent adverse pressure gradient downstream of it. By employing two different oil-film methods with upstream coating and full-coverage coating, a four-vortex model horseshoe vortex system can be identified ahead of each leading edge in the cascade, and the separation line of inlet boundary layer flow as well as the separation line of re-attached flow is provided as well. In addition, basic flow data such as secondary flow, aerodynamic loss, and flow turning angle downstream of the cascade are obtained.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11a
• /
• pp.21-25
• /
• 2001

In this study, recovery of plasma etching damage in PZT thin film with additive gas and re-annealing after etching have been investigated. The PZT thin films were etched as a function of Cl$_2$/CF$_4$ with addition of Ar and $O_2$ with inductively induced plasma. The etch rates of PZT thin films were 1450$\AA$/min at 30% additive Ar into (Cl$_2$(80%)+CF$_4$ (20%)) and 1100$\AA$/min at 10% additive $O_2$ into C(Cl$_2$(80%)+CF$_4$ (20%)). In order to recovery properties of PZT thin films after etching, the etched PZT thin films were re-annealed at various temperatures in at $O_2$ atmosphere. From the hysteresis curves, ferroelectrical properties are improved by $O_2$ re-annealing process. The improvement of ferroelectric behavior at annealed sample is consistent with the increase of the (100) and (200) PZT peaks revealed by x-ray diffraction (XRD). From x-ray photoelectron spectroscopy (XPS) analysis, intensity of Pb-O, Zr-O and Ti-O peak are increased and the chemical residue peak is reduced by $O_2$ re-annealing. The ferroelectric behavior consistent with the dielectric nature of Ti$_{x}$O$_{y}$ is recovered by $O_2$ recombination during rapid thermal annealing process.s.s.

• The Korean Journal of Food & Health Convergence
• /
• v.6 no.5
• /
• pp.19-25
• /
• 2020

The purpose of this study was to research and develop a step-type chemical liquid deodorizer including a liquid catalyst that can prevent civil complaints due to odor due to its excellent deodorizing performance. The main composition of chemical liquid deodorizer including liquid catalyst is cleaning deodorization, catalyst deodorization, chemical deodorization, water film plate, deodorization water circulation device, deodorization water injection device, catalyst management system, gas-liquid separation device, chemical supply device, deodorizer control panel, etc. It consists of a device. The air flow of the step-type liquid catalyst chemical liquid deodorizer is a technology that firstly removes basic odor substances, and the liquid catalyst installed in the subsequent process stably removes sulfur compounds, which are acidic odor substances, to discharge clean air. The efficiency of treating the complex odor of the prototype was 98.5% for the first and 99.6% for the second, achieving the target of 95%. The hydrogen sulfide treatment efficiency of the prototype was 100% for the first and 99.9% for the second, which achieved 95%, which was the target of the project. As a result, ammonia was removed by the reaction of ammonia and hydrogen sulfide.

• Proceedings of the KIEE Conference
• /
• 2006.07c
• /
• pp.1438-1439
• /
• 2006

$Ge_{2}Sb_{2}Te_5$(GST) thin film at present is a promising candidate for a phase change random access memory (PCRAM) based on the difference in resistivity between the crystalline and amorphous phase. PCRAM is an easy to manufacture, low cost storage technology with a high storage density. Therefore today several major chip in manufacturers are investigating this data storage technique. Recently, A. Pirovano et al. showed that PCRAM can be safely scaled down to the 65 nm technology node. G. T Jeonget al. suggested that physical limit of PRAM scaling will be around 10 nm node. Etching process of GST thin ra films below 100 nm range becomes more challenging. However, not much information is available in this area. In this work, we report on a parametric study of ICP etching of GST thin films in $Cl_2$/Ar chemistry. The etching characteristics of $Ge_{2}Sb_{2}Te_5$ thin films were investigated using an inductively coupled plasma (ICP) of $Cl_2$/Ar gas mixture. The etch rate of the GST films increased with increasing $Cl_2$ flow rate, source and bias powers, and pressure. The selectivity of GST over the $SiO_2$ films was higher than 10:1. X-ray photoelectron spectroscopy(XPS) was performed to examine the chemical species present in the etched surface of GST thin films. XPS results showed that the etch rate-determining element among the Ge, Sb, and Te was Te in the $Cl_2$/Ar plasma.