열탄화법을 사용한 탄화규소 나노와이어의 성장

노대호,김재수,변동진,양재웅,김나리,Rho, Dae-Ho,Kim, Jae-Soo,Byun, Dong-Jin,Yang, Jae-Woong,Kim, Na-Ri 한국재료학회 2003 한국재료학회지 Vol.13 No.10

SiC nanowires were synthesized by carbothermal reduction using metal catalysts. Synthesized nanowires had mean diameters of 30∼50 nm and several $\mu\textrm{m}$ length. The kind of catalysts affects form of SiC nanowire because of difference of growth mechanisms. These differences were made by catalyst's physical property and relative activities to the source gas. Ni acted a conventional catalyst of VLS growth mechanism. But, Case of Fe, SiC nanowire was grown by stable VLS growth mechanism without relation of growth conditions. SiC nanowire was grown by two step growth model using Cr catalyst. Conversion ratios to the SiC nanowire were increased with growth conditions. Case of Cr, conversion ratio was about 45% that was higher than other catalyst used. This high conversion ratio was obtained by the addition VS growth to radial direction on the as-grown nanowires.

Field-Emission Property of Self-Purification SiC/SiOx Coaxial Nanowires Synthesized via Direct Microwave Irradiation Using Iron-Containing Catalyst

Qing Zhou,Yongzhi Yu,Shan Huang,Jiang Meng,Jigang Wang 대한금속·재료학회 2017 ELECTRONIC MATERIALS LETTERS Vol.13 No.4

SiC/SiOx coaxial nanowires were rapidly synthesized via directmicrowave irradiation in low vacuum atmosphere. During the preparationprocess, only graphite, silicon, silicon dioxide powders were used as rawmaterials and iron-containing substance was employed as catalyst. Comprehensive characterizations were employed to investigate themicrostructure of the products. The results showed that a great quantityof coaxial nanowires with uniform sizes and high aspect ratio had beensuccessfully achieved. The coaxial nanowires consist of a silicon oxide(SiOx) shell and a β-phase silicon carbide (β-SiC) core that exhibited inspecial tube brush like. In additional, nearly all the products wereachieved in the statement of pure SiC/SiOx coaxial nanowires withoutthe existence of metallic catalyst, indicating that the self-removal of iron(Fe) catalyst should be occurred during the synthesis process. Photoluminescence (PL) spectral analysis result indicated that suchnovel SiC/SiOx coaxial nanowires exhibited significant blue-shift. Besides, the measurement results of field-emission (FE) demonstratedthat the SiC/SiOx coaxial nanowires had ultralow turn-on field andthreshold field with values of 0.2 and 2.1 V/μm, respectively. The heterojunctionstructure formed between SiOx shell and SiC core, lots ofemission sites, as well as clear tips of the nanowires were applied toexplain the excellent FE properties.

RF-Sputtering 법에 의한 SiC 나노와이어의 특성연구

정창구 ( Chang Gu Jeong ),김태규 ( Tae Gyu Kim ) 한국열처리공학회 2010 熱處理工學會誌 Vol.23 No.6

Silicon carbide nanowires were grown by heat treatment of the films at 1200℃ after amorphous SiC thin films were deposited on graphite substrate by radio frequency magnetron sputtering at 600℃. It was confirmed that SiC nanowires with the diameter of 20-60 nm and length of about 50nm were grown from Field Emission Scanning Election Microscope (FE-SEM) and Transmission Election Microscope (TEM) observation. The diameter of nanowires was increased as heat treatment time is increased. The nanowires were identified to β-SiC single crystalline from X-Ray Diffraction(XRD) analysis. It was observed from this study that deposition temperature of samples was critical to the crystallization of nanowires. On the other hand, the effect of deposition time was insignificant.

SILICON CARBIDE NANOWIRES FROM POLYVINYL ALCOHOL/SILICA ELECTROSPUN NANOFIBERS

H. DELAVARI H.,M. KOKABI 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2011 NANO Vol.6 No.1

The catalyst-free synthesis of silicon carbide (SiC) nanowires was carried out from polyvinyl alcohol (PVA)/silica electrospun nanofibers at high temperature. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), and thermogravimetery analysis (TGA) were employed to study morphology and formation of SiC nanowires. Based on the TGA analysis, the carbon yield was increased when inert gas flow rate and heating rate decreased and polymeric nanofibers has been stabilized. The XRD and TEM results showed that the produced nanowires were crystalline β-SiC and rather homogeneous in thickness with an average diameter around 50 to 70 nm and a length of more than 10 μm. Finally, a possible growth mechanism of β-SiC nanowire based on a vapor–solid (VS) mechanism was proposed.

The effect of the amount of activated carbon powder on the synthesis of SiC/SiO2 nanostructures via a chemical vapor growth method

Y. L. Chiew 한양대학교 세라믹연구소 2013 Journal of Ceramic Processing Research Vol.14 No.1

In this study, the effects of different amounts of activated carbon powder on the growth of SiC/SiO2 nanostructures were examined. The nanostructures were formed using a simple chemical vapor growth setup using only oxidized silicon (Si) wafers and activated carbon powder. The addition of carbon powder into the system led to the formation of four main SiC/SiO2 products namely nanograins, nanowires, nanowebs and nanocables along with other side products of SiO2 nanowires and nanoparticles, depending on their growth location on the oxidized Si substrates. The possible growth mechanisms for these nanostructures are discussed.

Comparison of AIN Nanowire-Like Structures Grown by using Mixed-Source Hydride Vapor Phase Epitaxy Method

김경화,이강석,안형수,양민,이삼녕,전인준,조채용,전헌수,김석환 한국물리학회 2019 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.75 No.3

Four AlN nanowire-like structures were simultaneously grown directly without a buffer layer on four substrates-sapphire, quartz, Si(111), and 6H-SiC-via a mixed-source hydride vapor phase epitaxy (HVPE) method using a mixed source (Al+Ga) containing a small quantity of Ga at 1150 °C for 2 h. Deposition was carried out using a simplified reactor designed in series without any separation between the source and the growth zones. AlN nanostructures with hexagonal crystal structures were grown successfully and directly on thin, pre-grown AlN nucleation areas on the quartz substrates. Furthermore, AlN nanostructures were grown on the sapphire substrate without a buffer layer and on pre-grown epilayers on the Si (111) and the 6H-SiC substrates, respectively. The characteristics of the AlN nanowire-like structures grown on the four substrates were investigated using energy-dispersive X-ray spectrometry and field-emission scanning electron microscopy.

탄화규소 (3C-SiC) 나노선 트랜지스터의 제작 및 2D ATLAS 시뮬레이션 비교 연구

김동주,이승용,형정환,이상권 한국물리학회 2008 새물리 Vol.57 No.5

We report on the electrical characteristics of 3C-SiC nanowire (NW) field-effect transistors (FETs), which were prepared by using conventional electron-beam lithography (EBL). The SiC NWs used in the FETs were normally in the range of 40 $\sim$ 100 nm. In addition, the current-voltage (I-V) characteristics of the SiC NW FETs were compared with the simulated results. From the 2D ATLAS simulation, the carrier mobility and the on/off ratio were estimated to be $\sim$3.06 $\times$ 10$^3$ cm$^2$/V$\cdot$s and $\sim$ 6.16, respectively. We also noticed that detailed studies, such as direct doping and modulation of the doping in SiC NWs, are required for further fabrication of high-performance SiC NW-based devices. 본 연구에서는 탄화규소 나노선 트랜지스터를 제작하여 실제 소자의 전기적인 특성을 분석하였으며 실험에서 나타난 결과를 2D ATLAS 시뮬레이션을 이용하여 비교하였다. 실험에서 제작된 탄화규소 나노선은 hot-wall 방식의 화학기상증착 방법을 이용하여 합성하였으며, 지름은 40 $\sim$ 100 nm 이다. 합성된 탄화규소 나노선을 후면 게이트 전계효과 트랜지스터 (back-gated field-effect transistors) 로 제작하였으며, 이를 2D ATLAS 시뮬레이션을 통해 탄화규소 나노선 트랜지스터 소자 동작특성을 비교 분석하였다. 2D ATLAS 시뮬레이션에서의 탄화규소 나노선의 길이와 채널의 길이, 지름은 제작된 소자와 같은 4 $\mu$m, 3 $\mu$m, 45 nm 이고, 일정한 전하 농도를 갖는다고 가정하였으며, 지름이 작아짐에 따라 나타나는 양자효과는 본 연구에서는 배제하였다. 실험결과와 시뮬레이션의 결과를 비교한 후 전하 농도가 1.5 $\times$ 10$^{17}$ cm$^{-3}$ 일 때 전류 on/off ratio ($I_{on}/I_{off}$) 와 이동도 ($\mu$) 는 각각 6.16 과 3.06 $\times$ 10$^3$ cm$^2$/V$\cdot$s 를 갖는 소자 제작이 가능함을 알 수 있었다.

a-, c-, m-면방향의 4H-SiC 기판에 형성된 ZnO 나노선 가스센서의 300℃에서 CO 가스 감지 특성

정경환,이정호,강민석,구상모,Jeong, Gyeong-Hwan,Lee, Jung-Ho,Kang, Min-Seok,Koo, Sang-Mo 한국전기전자재료학회 2013 전기전자재료학회논문지 Vol.26 No.6

ZnO nanowires on the a-, c- and m-plane oriented 4H-SiC substrates were grown by using a high temperature tube furnace. Ti/Au electrodes were deposited on ZnO nanowires and a-, c- and m-plane 4H-SiC substrates, respectively. The shape and density of the ZnO nanowires were investigated by field emission scanning electron microscope. It was found that the growth direction of nanowires depends strongly on growth parameters such as growth temperature and pressure. In this work, The sensitivity of nanowires formed a-, c- and m-plane oriented 4H-SiC gas sensor was measured at $300^{\circ}C$ with CO gas concentration of 80%. The nanowires grown on a-plane oriented 4H-SiC show improved sensing performance than those on c- and m-plane oriented 4H-SiC due to the increased density of nanowire on a-plane 4H-SiC.

4H-SiC 기판의 a-, c-, m-면방향에 따른 ZnO 나노선의 Photoluminescence 특성 분석

김익주,여인형,문병무,강민석,구상모,Kim, Ik-Ju,Yer, In-Hyung,Moon, Byung-Moo,Kang, Min-Seok,Koo, Sang-Mo 한국전기전자재료학회 2012 전기전자재료학회논문지 Vol.25 No.5

ZnO thin films were deposited on a-, c- and m- plane oriented 4H-SiC substrates by pulsed laser deposition. ZnO nanowires were formed on substrates by tube furnace. Shape and density of the ZnO nanowires were investigated by field emission scanning electron microscope. Average surface roughness and root mean square surface roughness were measure by atomic force microscope. Optical properties were investigated by Photoluminescence measurement. Density of ZnO nanowires grown on a-, c- and m-plane oriented 4H-SiC substrates were 17.89 ${\mu}m^{-2}$, 9.98 ${\mu}m^{-2}$ and 2.61 ${\mu}m^{-2}$, respectively.

Microcellular SiC foams containing in situ grown nanowires for electromagnetic interference shielding

Praveen Wilson,Sujith Vijayan,K. Prabhakaran 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.80 No.-

Microcellular SiC foams (MSiCFs) are produced by thermal setting of dispersions of silicon and NaClpowders in molten sucrose-glycerol solutions in a mould followed by carbonization, NaCl removal andreaction bonding at 1500 C. The acidic silica layer on silicon particle surface catalyses the setting of thepastes byOH condensation. The SiC nanowires grown in situ by a catalyst-free vapour–solid (VS)mechanism creates web-like architecture within the microcells (cell size2 to 22 mm) of the foams. TheMSiCFs with porosity in the range of 86.8–91.1 vol.% exhibit thermal conductivity and compressivestrength in the ranges of 0.334–0.758 W m 1 K 1 and 0.97–2.38 MPa, respectively. The MSiCFs showexcellent electromagnetic interference (EMI) shielding property in the X-band frequency regionenhanced by the in situ grown SiC nanowires within microcells. The EMI shielding effectiveness (45.6 dB)and specific shielding effectiveness (137 dB g-1 cm3) are the highest reported for SiC foams.