• 한국전기전자재료학회논문지
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• 제30권1호
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• pp.1-6
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• 2017

Tungsten carbide (WC) has been suggested as a new buffer layer for the GaN-on-Si technology. We have investigated and optimized the sputtering condition of WC layer on the Si-substrate. We confirmed the suppression of the Si melt-back phenomenon. In addition, surface energy of WC/Si layer was measured to confirm the possibility as a buffer layer for GaN growth. We found that the surface energy(${\gamma}=82.46mJ/cm^2$) of WC layer is very similar to that of sapphire substrate(${\gamma}=82.71mJ/cm^2$). We grow GaN layer on the WC buffer by using gas-source MBE, and confirm that it is available to grow a single crystalline GaN layer.

• 한국전기전자재료학회논문지
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• 제30권3호
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• pp.139-143
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• 2017

N-type crystalline silicon solar cells have high metal impurity tolerance and higher minority carrier lifetime that increases conversion efficiency. However, junction quality between the boron diffused layer and the n-type substrate is more important for increased efficiency. In this paper, the current status and prospects for boron diffused layers in N-type crystalline silicon solar cell applications are described. Boron diffused layer formation methods (thermal diffusion and co-diffusion using $a-SiO_X:B$), boron rich layer (BRL) and boron silicate glass (BSG) reactions, and analysis of the effects to improve junction characteristics are discussed. In-situ oxidation is performed to remove the boron rich layer. The oxidation process after diffusion shows a lower B-O peak than before the Oxidation process was changed into $SiO_2$ phase by FTIR and BRL. The $a-SiO_X:B$ layer is deposited by PECVD using $SiH_4$, $B_2H_6$, $H_2$, $CO_2$ gases in N-type wafer and annealed by thermal tube furnace for performing the P+ layer. MCLT (minority carrier lifetime) is improved by increasing $SiH_4$ and $B_2H_6$. When $a-SiO_X:B$ is removed, the Si-O peak decreases and the B-H peak declines a little, but MCLT is improved by hydrogen passivated inactive boron atoms. In this paper, we focused on the boron emitter for N-type crystalline solar cells.

• 대한한의학회지
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• 제30권3호
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• pp.15-27
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• 2009

Objective : This study was carried to identify the anatomical component of BMM (Foot Taeyang Meridian Muscle in the human truncus), and further to help the accurate application to real acupunctuation. Methods: The human truncus was stripped off in order to demonstrate muscles, nerves and other components, and to display the internal structure of the BMM, dividing into outer, middle, and inner parts. Results: The BMM in the human truncus is composed of muscles, nerves, ligaments etc. The internal composition of the BMM in the human truncus is as follows: 1. Muscle A. Outer layer: medial palpebral ligament, orbicularis oculi, frontalis, galea aponeurotica, occipitalis, trapezius, latissimus dorsi, thoracolumbar fascia, gluteus maximus. B. Middle layer: frontalis, semispinalis capitis, rhomboideus minor, serratus posterior superior, splenius cervicis, rhomboideus major, latissimus dorsi, serratus posterior inferior, levator ani. C. Inner layer: medial rectus, superior oblique, rectus capitis, spinalis, rotatores thoracis, longissimus, longissimus muscle tendon, longissimus muscle tendon, multifidus, rotatores lumbaris, lateral intertransversi, iliolumbaris, posterior sacroiliac ligament, iliocostalis, sacrotuberous ligament, sacrospinous ligament. 2. Nerve A. Outer layer: infratrochlear nerve, supraorbital n., supratrochlear n., temporal branch of facial n., auriculotemporal n., branch of greater occipital n., 3rd occipital n., dorsal ramus of 1st, 2nd, 3rd, 4th, 5th, 6th, 7th, 8th, 9th, 10th, 11th, 12th thoracic n., dorsal ramus of 1st, 2nd, 3rd, 4th, 5th lumbar n., dorsal ramus of 1st, 2nd, 3rd, 4th, 5th sacral n. B. Middle layer: accessory nerve, anicoccygeal n. C. Inner layer: branch of ophthalmic nerve, trochlear n., greater occipital n., coccygeal n., Conclusions : This study shows that BMM is composed of the muscle and the related nerves and there are some differences from already established studies from the viewpoint of constituent elements of BMM at the truncus, and also in aspect of substantial assay method. In human anatomy, there are some conceptional differences between terms (that is, nerves which control muscles of BMM and those which pass near by BMM).

• 대한금속재료학회지
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• 제47권9호
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• pp.591-596
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• 2009

$TiN_xO_y/TiN_x$ multi-layer thin films with a high resistance(${\sim}k{\Omega}$) were deposited on $SiO_2/Si$ substrates at room temperature by sputtering. The $TiN_x$ thin films show island and smooth surface morphology in samples prepared by ${\alpha}$ and RF magnetron sputtering, respectively. $TiN_xO_y/TiN_x$ multi-layer in has been developed to control temperature coefficient of resistance(TCR) by the incorporation of $TiN_x$ layer(positive TCR) inserted into $TiN_xO_y$ layers(negative TCR). Electrical and structural properties of sputtered $TiN_xO_y/TiN_x$ multi-layer films were investigated as a function of annealing temperature. In order to achieve a stable high resistivity, multi-layer films were annealed at various temperatures in oxygen ambient. Samples annealed at $700^{\circ}C$ for 1 min exhibited good TCR value of approximately $-54 ppm/^{\circ}C$ and a stable high resistivity around $20k{\Omega}/sq$. with good reversibility.

• Journal of Applied Biological Chemistry
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• 제54권2호
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• pp.89-93
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• 2011

오이풀 아세톤 추출물로부터 용매분획물의 기능성 화장품 소재로 활용하기 위하여 항산화 효과를 측정한 후 화장품 소재로서의 가능성을 검증하였다. 항산화 효과를 확인하기 위하여 electron donating ability을 측정한 결과 ethyl actate 층과 n-butyl alcohol 층이 전 농도에서 대조군 BHA와 유사한 활성을 나타내었으며, ABTS radical cation decolorization assay 결과 ethyl acetate 층, n-butyl alcohol 층, water 층 모두 전 농도에서 99% 이상의 효과를 나타내어 BHA와 유사하였다. hydrogen peroxide scavenging assay 결과 ethyl acetate 층, n-butyl alcohol 층이 대조군 ascorbic acid 보다 효과가 높았다. Superoxide dismutase (SOD) 유사 활성 측정 결과, n-butyl alcohol 층이 1,000 ${\mu}g/mL$ 농도에서 50% 이상의 효능이 있었으며, Superoxide anion 라디칼 소거능은 n-butyl alcohol 층의 1,000 ${\mu}g/mL$에서 45%의 효과가 있었다. 이상의 결과로 미루어 보아 오이풀 아세톤 추출물의 분획물 중 ethyl acetate 층과 n-butyl alcohol 층에서 항산화 효과가 있었으며, 새로운 항산화 화장품의 소재로서 가능성을 확인 할 수 있었다.

• 전자공학회논문지D
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• 제35D권8호
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• pp.15-23
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• 1998

Single crystalline I $n_{x}$G $a_{1-x}$ N thin film was grwon by MOCVD on (001) sapphire substrate for the blue light emitting devices. A good quality of I $n_{0.13}$G $a_{0.87}$N/GaN heterostructure grwon above 700.deg. C was confiremed by various characterization techniques of AFM, RHEED and DC-XRD. Through PL measurement at room temperautre for the Si-Zn co-doped I $n_{x}$G $a_{a-x}$N/GaN structure grwon at 800.deg. C to obtain blue wavelength emission, 460-470 nm and 425 nm emission peak were observed, which are believed to be from donor-to-acceptor pair transition and band edge emission of In/x/G $a_{1-x}$ N, respectively. The result of PL measurement of the undoped MQW I $n_{x}$G $a_{1-x}$ N layer at low temperature confirmed that the strong MQW peak was resulted by exciton from the GAN barrier and carrier of DA pair confined into the well layer.ll layer.yer.r.

• 마이크로전자및패키징학회지
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• 제22권4호
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• pp.65-70
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• 2015

히트 싱크용 소재에 응용할 목적으로 단층금속과 2층 단면구조 복합재료에 대해 열전도 특성을 연구하였다. 단층금속으로는 알루미늄합금(Al6061)을 사용했으며, 2층 단면구조 복합재료로는 Al6061기판에 질화알루미늄(AlN)을 스크린 인쇄한 층상구조 복합재료를 선택하였다. 섬광법으로 측정한 열확산계수와 비열 및 밀도를 사용해서 열전도도를 측정하였다. 실험을 통해 얻은 열전도 특성 값을 참고문헌에 보고된 자료를 사용해 계산한 값과 비교하였다. Al6061 기판에 스크린인쇄법으로 AlN 후막을 형성시킨 2층 단면구조 복합재료 시편의 열전도도는 AlN 후막의 두께가 증가할수록 선형적으로 감소하였다. 측정한 복합재료의 열전도도는 두께가 $53{\mu}m$과 $163{\mu}m$일 때, 각각 $114.1W/m{\cdot}K$와 $72.3W/m{\cdot}K$로 나타났다. 또한, 스크린 인쇄한 AlN 후막의 열전도도를 열전도비저항에 대한 혼합법칙을 적용해서 평가하였다. AlN 후막의 두께가 $53{\mu}m$와 $163{\mu}m$인 경우, 스크린 인쇄한 AlN 후막의 열전도도는 각각 $9.35W/m{\cdot}K$와 $12.40W/m{\cdot}K$로 나타났다.

• Tribology and Lubricants
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• 제18권4호
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• pp.260-266
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• 2002

In this study, the effects of oxide layer farmed on the wear tracks of TiN coated silicon wafer on friction and wear characteristics were investigated. Silicon wafer was used for the substrate of coated disk specimens, which were prepared by depositing TiN coating with 1 ${\mu}{\textrm}{m}$ in coating thickness. AISI 52100 steel ball was used fur the counterpart. The tests were performed both in air for forming oxide layer on the wear track and in nitrogen to avoid oxidation. This paper reports characterization of the oxide layer effects on friction and wear characteristics using X-ray diffraction(XRD), Auger electron spectroscopy(AES), scanning electron microscopy (SEM) and multi-mode atomic force microscope(AFM).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.154-154
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• 2009

Cr capping layer를 이용하여 Titanium germanide의 열적 안정성을 향상시키는 연구를 수행하였다. n-type Ge(100) 기판 위에 전자빔 증착기를 이용하여 30nm 두께의 Ti와 Cr capping layer를 증착하고 $400\;^{\circ}C$에서 $800\;^{\circ}C$까지 30초간 N2 분위기로 급속 열처리하여 Ti germanide를 형성하였다. XRD결과로부터 Cr capping layer의 유무에 관계 없이 Ti germanide가 형성된 것을 관찰할 수 있었다. Ge 기판 위에 CTLM 패턴을 형성하고 실험을 진행하여 Ti germanide의 I-V 측정 데이터를 통해 Ohmic 특성을 알아보았고, contact resistance, sheet resistance, specific contact resistance를 구하였다.

• 한국정밀공학회지
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• 제17권3호
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• pp.149-157
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• 2000

Tool wear in the shearing process such as blanking, piercing and trimming is very important, because it has great effects on the dimensional accuracy, working efficiency and economy. Most of tools in the shearing process have the coated layer at surface fur good wear and corrosion resistance. When the surface of tool is teated, the wear Phenomena of coated surface layer and inner layer may be different. This paper describes a computer modelling technique by the finite element method in order to investigate the wear mechanism and to predict the wear profile of Ti-N coated tool in piercing process according to the volume of Production. Wear coefficients of the coated layer and inner layer are obtained through Pin-on-Disk wear test, respectively. To verify the effectiveness of the suggested technique, the technique is applied to wear analysis in piercing recess of piston pin and simulation results are compared with experimental ones.