• Proceedings of the Materials Research Society of Korea Conference
• /
• 1998.11a
• /
• pp.36-36
• /
• 1998

• Transactions on Electrical and Electronic Materials
• /
• v.11 no.6
• /
• pp.266-270
• /
• 2010

The effect of an Ar plasma treatment on polycarbonate substrates was investigated using $TiO_2$ coatings produced by reactive ion-beam assisted sputtering. The typical pressure used during sputtering was about $10^{-4}$ Torr. After the Ar plasma treatment, the contact angle of a water droplet was reduced from $88^{\circ}$ to $52^{\circ}$ and then further decreased to $12^{\circ}$ with the addition of oxygen into the chamber. The surface of the polycarbonate substrate hanged from hydrophobic to hydrophilic with these treatments and revealed its changing nano-scale roughness. The $TiO_2$ films on the treated surface showed various colors and periodic ordering dependant on the film thickness due to optical interference.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.04b
• /
• pp.39-42
• /
• 2000

As gate dimensions continue to shrink below $0.2{\mu}m$, improving CD (Critical Dimension) control has become a major challenge during CMOS process development. Anti-Reflective Coatings are widely used to overcome high substrate reflectivity at Deep UV wavelengths by canceling out these reflections. In this study, we have investigated Batchtype system for PECVO SiOxNy as Anti-Reflective Coatings. The Singletype system was baseline and Batchtype system was new process. The test structure of Singletype is SiON $250{\AA}$ + Cap Oxide $50{\AA}$ and Batchtype is SiON $250{\AA}$ + Cap Oxide $50{\AA}$ or N2O plasma treatment. Inorganic chemical vapor deposition SiOxNy layer has been qualified for bottom ARC on Poly+WSix layer, But, this test was practiced on the actual device structure of TiN/Al-Cu/TiN/Ti stacks. A former day, in Batchtype chamber thin oxide thickness control was difficult. In this test, Batchtype system is consist of six deposition station, and demanded 6th station plasma treatment kits for N2O treatment or Cap Oxide after SiON $250{\AA}$. Good reflectivity can be obtained by Cap Oxide rather than N2O plasma treatment and both system of PECVD SiOxNy ARC have good electrical properties.

• Applied Science and Convergence Technology
• /
• v.25 no.3
• /
• pp.51-55
• /
• 2016

The surface treatment of a titanium implant is investigated with a non-thermal atmospheric pressure plasma jet. The plasma jet is generated by the injection of He and $O_2$ gas mixture with a sinusoidal driving voltage of 3 kV or more and with a driving frequency of 20 kHz. The generated plasma plume has a length up to 35 mm from the jet outlet. The wettability of 4 different titanium surfaces with plasma treatments was measured by the contact angle analysis. The water contact angles were significantly reduced especially for $O_2/He$ mixture plasma, which was explained with the optical emission spectroscopy. Consequently, plasma treatment enhances wettability of the titanium surface significantly within the operation time of tens of seconds, which is practically helpful for tooth implantation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.11a
• /
• pp.214-215
• /
• 2007

Etch rates and surface chemistry of phenol formaldehyde-based photoresist after short time $O_2\;and\;N_2O$ radio frequency (RF) plasma treatment depending on exposure time were investigated. It was found that the etch rate of photoresist sharply increased after discharge turn on and reached a limit with increase in plasma exposure time in both gases. X-ray photoelectron spectroscopy (XPS) analysis showed that the surface chemical structure become nearly constant after the treatment of 15 sec. Concentration of surface oxygen-containing groups after processing both in oxygen and in $N_2O$ plasmas is similar.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2015.08a
• /
• pp.62-62
• /
• 2015

In this study, we study the effects of CF4 plasma treatment on the characteristics of enhancement mode (E-mode) AlGaN/GaN high electron mobility transistors (HEMTs). The CF4 plasma is generated by inductively coupled plasma reactive ion etching (ICP-RIE) system. The CF4 gas is decomposed into fluorine ions by ICP-RIE and then fluorine ions will effect the AlGaN/GaN interface to inhibit the electron transport of two dimension electron gas (2DEG) and increase channel resistance. The CF4 plasma method neither like the recessed type which have to utilize Cl2/BCl3 to etch semiconductor layer nor ion implantation needed high power to implant ions into semiconductor. Both of techniques will cause semiconductor damage. In the experiment, the CF4 treatment time are 0, 50, 100, 150, 200 and 250 seconds. It was found that the devices treated 100 seconds showed best electric performance. In order to prove fluorine ions existing and CF4 plasma treatment not etch epitaxial layer, the secondary ion mass spectrometer confirmed fluorine ions truly existing in the sample which treatment time 100 seconds. Moreover, transmission electron microscopy showed that the sample treated time 100 seconds did not have etch phenomena. Atomic layer deposition is used to grow Al2O3 with thickness 10, 20, 30 and 40 nm. In electrical measurement, the device that deposited 20-nm-thickness Al2O3 showed excellent current ability, the forward saturation current of 210 mA/mm, transconductance (gm) of 44.1 mS/mm and threshold voltage of 2.28 V, ION/IOFF reach to 108. As IV concerning the breakdown voltage measurement, all kinds of samples can reach to 1450 V.

• Fashion & Textile Research Journal
• /
• v.16 no.3
• /
• pp.456-461
• /
• 2014

The objective of this study is to give PP(polypropylene) fabric a good affinity for water. Oxygen plasma was treated to PP fabrics in a commercial glow discharge reactor with different RF power, discharge pressure, and reaction time. The PP fiber surfaces were characterized by the measurement of contact angle and ESCA. A JEOL scanning electron microscope was used to observe the surface morphology of fibers. The spontaneous water uptake amount of PP fabrics was determined by the demand wettability test. To determine the effect of aging on the surface properties of $O_2$ plasma treated PP, all the above measurements of the samples were carried out after 1, 7, 30, 60, and 150 days. The results are as follows. The PP fiber surfaces treated by $O_2$ plasma treatment have a chemical composition that consisted of various oxygen containing polar groups. Consequently, the contact angles of the treated PP fibers decreased, which improved the water uptake rate of PP fabrics. Surface roughness of the treated PP affected the fabric wettabiity as well. Wettability of the treated PP decreased and leveled off with aging. The $O_2$ plasma treatment is a simple and effective method to increase the water uptake rate of PP fabrics.

• Journal of Food Hygiene and Safety
• /
• v.32 no.1
• /
• pp.64-69
• /
• 2017

This study was conducted to investigate the effect of cold plasma combined with UV-C irradiation against Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, and Listeria monocytogenes on lettuce. E. coli O157:H7, S. Typhimurium, and L. monocytogenes, corresponding to approximately 5.82, 5.09, 5.65 log CFU/g, were inoculated on lettuce, respectively. Then, the lettuce was treated with cold plasma, UV-C and combination (cold plasma + UV-C), respectively. The treated lettuce was stored for 9 days at $4^{\circ}C$ for microbiological analysis and sensory evaluation. Cold plasma reduced the populations of E. coli O157:H7, S. Typhimurium, and L. monocytogenes by 0.26, 0.65, and 0.93 log CFU/g, respectively. Each microorganism were reduced by 0.87, 0.88, and 1.14 log CFU/g after UV-C treatment. And, the combined treatment that was treated by cold plasma after UV-C treatment reduced the populations of inoculated microorganisms by 1.44, 2.70, 1.62 log CFU/g, respectively. The all treatment significantly (p < 0.05) reduced the populations of all inoculated bacteria compared to untreated lettuce. UV-C combined with cold plasma was the most effective for reducing the pathogenic bacteria on lettuce, by showing log-reductions of ${\geq}2.0\;log\;CFU/g$. All treatment was not significantly different until 6 day storage compared to control group in terms of appearance, texture and overall acceptability. Therefore, the combined treatment will be an effective intervention method to control the bacteria on lettuce.

• Journal of the Speleological Society of Korea
• /
• no.76
• /
• pp.61-66
• /
• 2006

The present report is the investigation of the effects of the HIP treatment on plasma-sprayed ceramic coating of $Al_2O_3$, $Al_2O_3-SiO_2$ on the metal substrate. These effects were characterized by phase identification, Vickers hardness measurement, and tensile test before and after HIPing.

• Korean Journal of Materials Research
• /
• v.24 no.11
• /
• pp.639-643
• /
• 2014

Hydrophilic $SiO_2$ layers were obtained by the atmospheric-pressure plasma treatment. Superhydrophobic $SiO_2$ layers were first deposited by the electrospray deposition method. The electrospunable solution that was prepared based on the solgel method was sprayed on Si (100) substrates. The surface of the electrosprayed $SiO_2$ layers consisted of the agglomeration of nano-sized grains, which led to a very high roughness and revealed a very high contact angle to water droplets over $162^{\circ}$. After having been exposed to the atmospheric $Ar/O_2$ plasma, the observed superhydrophobicity of the $SiO_2$ layers were greatly changed: a dramatic variation of the water contact angle from $162^{\circ}$ to $3^{\circ}$, namely realization of superhydrophillicity. Interestingly, the surface microstructure was almost preserved. According to the XPS analysis, it is more likely that thanks to the plasma exposure, the surface of $SiO_2$ layers will be cleaned in terms of organic species that are hydrophobic-inducing, consequently leading to the hydrophilic nature observed for the plasma-exposed $SiO_2$ layers.