• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.32 no.1
• /
• pp.1-6
• /
• 2022

In this research, a ring-shaped silicon carbide (SiC) single crystal manufactured using the PVT (Physical Vapor Transport) method was proposed to be applied to a SiC focus ring in semiconductor etching equipment. A cylindrical graphite structure was placed inside the graphite crucible to grow a ring-shaped SiC single crystal by the PVT method. SiC single crystal ring without crack was successfully obtained in case of using SiC single crystal wafer as a seed. A plasma etching process was performed to compare plasma resistance between the CVD-SiC focus ring and the PVT-SiC focus ring. The etch rate of ring materials in PVT-single crystal SiC focus ring was definitely lower than that of CVD-SiC focus ring, indicating better plasma resistance of PVT-SiC focus ring.

• Korean Journal of Materials Research
• /
• v.9 no.11
• /
• pp.1129-1136
• /
• 1999

TIN films were prepared on Si(100) substrate by ICP-CVD(inductive1y coupled plasma enhanced chemical vapor deposition) using TEMAT(tetrakis ethylmethamido titanium : Ti$[\textrm{N}\textrm{(CH)}_{3}\textrm{C}_{2}\textrm{H}_{5}]_{4}$) precursor at various deposition conditions. Phase, microstructure, and the electrical properties of TIN films were characterized by x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), high resolution transmission electron microscopy (HRTEM) and electrical measurements. Polycrystalline TiN films with B1 structure were grown at temperatures over $200^{\circ}C$. Preferentially oriented along TiN(111) films were obtained at temperatures over $300^{\circ}C$ with the flow rates of 10, 5, and 5 sccm for TEMAT, $\textrm{N}_{2}$ and Ar gas. The TiN/Si(100) interface was flat and no chemical reaction between TIN and $\textrm{SiO}_2$ was found. The resistivity, carrier concentration and the carrier mobility for the TiN sample prepared at $500^{\circ}C$ are 21 $\mu\Omega$cm, 9.5$\times\textrm{10}^{18}\textrm{cm}^{-3}$ and $462.6\textrm{cm}^{2}$/Vs, respectively.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.08a
• /
• pp.440-440
• /
• 2012

Nanomaterials have emerged as new building blocks to construct light energy harvesting assemblies. Size dependent properties provide the basis for developing new and effective systems with semiconductor nanoparticles, quantized charging effects in metal nanoparticle or their combinations in 2 and 3 dimensions for expanding the possibility of developing new strategies for photovoltaic system. As top-down approach, we developed a simple and effective method for the large scale formation of self-assembled Cu(In,Ga)$Se_2$ (CIGS) nanostructures by ion beam irradiation. The compositional changes and morphological evolution were observed as a function of the irradiation time. As the ion irradiation time increased, the nano-dots were transformed into a nano-ridge structure due to the difference in the sputtering yields and diffusion rates of each element and the competition between sputtering and diffusion processes during irradiation. As bottom-up approach, we developed the growth of CIGS nanowires using thermal-chemical vapor deposition (CVD) method. Vapor-phase synthesis is probably the most extensively explored approach to the formation of 1D nanostructures such as whiskers, nanorods, and nanowires. However, unlike binary or ternary chalcogenides, the synthesis of quaternary CIGS nanostructures is challenging because of the difficulty in controlling the stoichiometry and phase structure. We introduced a method for synthesis of the single crystalline CIGS nanowires in the form of chalcopyrite using thermal-CVD without catalyst. It was confirmed that the CIGS nanowires are epitaxially grown on a sapphire substrate, having a length ranged from 3 to 100 micrometers and a diameter from 30 to 500 nm.

• Journal of the Microelectronics and Packaging Society
• /
• v.30 no.2
• /
• pp.60-64
• /
• 2023

In this study, the electrical contact resistance characteristics between graphene and metals, which is one of important factors for the performance of graphene-based devices, were compared. High-quality graphene was synthesized by chemical vapor deposition (CVD) method, and Al, Cu, Ni, and Ti as electrode materials were deposited on the graphene surface with equal thickness of 50 nm. The contact resistances of graphene transferred to SiO₂/Si substrates and metals were measured by the transfer length method (TLM), and the average contact resistances of Al, Cu, Ni, and Ti were found to be 345 Ω, 553 Ω, 110 Ω, and 174 Ω, respectively. It was found that Ni and Ti, which form chemical bonds with graphene, have relatively lower contact resistances compared to Al and Cu, which have physical adsorption properties. The results of this study on the electrical properties between graphene and metals are expected to contribute to the realization of high-performance graphene-based devices including electronics, optoelectronic devices, and sensors by forming low contact resistance with electrodes.

• Journal of the Korean Vacuum Society
• /
• v.4 no.S1
• /
• pp.1-6
• /
• 1995

Polycrystalline Si films have been used in many applications such as thin film transistors(TFT), image sensors and LSI applications. In this research deposition of Si films at low temperatures with remote plasma enhanced CVD from Si2H6-SiF4-H2 on SiO2 was studied and their crystallinity was investigated. It was condluded that growth of crystalline Si films was favorable with (1) low Si2H6 flow rates, (2) moderate plasma power, (3) moderate SiF4 flow rates, (4) moderate substrate temperature, and (5) suitable method of surface cleaning.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.6 no.3
• /
• pp.309-317
• /
• 1996

Al2O3 thin films were deposited on Si-wafer (100) using organo-aluminum compounds at low pressure by chemical vapor deposition (CVD) method. The vapor of the organo-metallic precursor was carried by pure N2 gas. The deposition rate increased and then saturated as Tsub increased with increasing the AIP flow rate. The main contamination didn't found in deposited films except carbon. The H-O(H2O) IR absorption band decreased in intensity as the deposition temperature increased, and completely disappeared through annealing.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2003.07a
• /
• pp.201-202
• /
• 2003

We developed a novel growth method of aligned carbon nanotubes. Aligned carbon nanotubes are grown on a metal catalyst on a glass substrate using biased Helicon plasma chemical vapor deposition (HPECVD) of $CH_4/H_2$ gases from 400 C to 500 C. The Helicon plasma source is one of the high-density plasma sources and is promising for low temperature carbon deposition. A Ni film was used as a catalyst to reduce the activation energy of the nanotubes' growth. The carbon nanotubes were deposited on the nickel catalysis layer selectively.

• 대한예방의학회:학술대회논문집
• /
• 2003.04a
• /
• pp.30-37
• /
• 2003

o Cohort study became the major approach to study of chronic diseases such as CVD and cancer o Cohort can be population-based or volunteer-based o Types of be population-be categorized by source population and selection mechanism o More and more cohort studies involve biological specimens, such as blood, urine, toenail, cheek cells, etc. o Multi-center and multi-national collaboration is an effective way to increase sample size. o Current statistical method typically use time-to-event analysis by Cox proportional hazard model.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2004.08a
• /
• pp.167-167
• /
• 2004

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2014.11a
• /
• pp.13-13
• /
• 2014

그래핀은 높은 열전도도, 이동도, 물리적 강도, 화학적 안정성을 갖는 물질로써 가장 활발하게 연구가 진행되고 있는 소재이다. 하지만, 높은 품질의 그래핀을 생산하기 위한 Chemical Vapor Deposition(CVD) 그래핀 제조 방법은 높은 공정단가와 낮은 수율 문제로 적용에 어려움을 겪고 있다. 본 연구에서는 초고순도 그래핀 플레이크를 RF thermal plasma를 이용하여 제조함으로써 이러한 문제점을 해결하고자 한다.