• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.368-368
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• 2010

Monolayers of graphite can be grown by fine controlled surface graphitization on the surfaces of various metallic and semiconducting materials. Epitaxial graphene grown on polished silicon carbide crystal surfaces has drawn much attention due to well known vacuum annealing procedures from surface analysis methods, especially scanning tunneling microscopy(STM) and scanning tunneling spectroscopy(STS). In this study, we have grown single layer and few layer graphene on silicon terminated 6H-SiC(0001) crystals. The growth of graphene layers were observed by low energy electron diffraction(LEED) patterns. Scanning tunneling microscopy and spectroscopy measurements were performed to illustrate the electronic structure which may display some clue on the influence of the underlying structure. Spatially resolved STS results acquired at the edges of epitaxial graphene show in detail the electron density of states, which is compared to theoretical calculations. STM measurements were also done on graphene films grown by chemical vapor deposition(CVD) and transferred onto a SiC(0001) crystal. These observations may provide a hint for the understanding of carrier scattering at the edges.

• 전기전자학회논문지
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• 제23권3호
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• pp.811-816
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• 2019

초고진공 화학기상증착장치(UHV-CVD)에 의해 성장된 실리콘-흡착된 산소(Si-O) 초격자가 실리콘 양자전자소자를 위한 에피택셜 장벽으로 소개되었다. 전류-전압 측정 결과 높은 브레이크다운 전압을 갖는 매우 안정하고 양호한 절연특성을 나타내었다. 에피택셜 성장된 Si-O 초격자는 SOI(silicon on insulator)를 대체할 수 있는 절연층으로도 사용될 수 있음을 보여준다. 이 두꺼운 장벽은 전계효과트랜지스터(FET)의 절연 게이트로 유용하게 사용될 수 있어 FET 위에 또 다른 FET를 제작할 수 있으므로 미래 실리콘계 3차원 집적회로의 궁극적인 목표에 한층 더 다가갈 수 있는 가능성을 보여주는 것이다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1995년도 춘계학술대회 논문집
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• pp.26-30
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• 1995

We describe the preparation and characterization of epitaxial thin films made with high temperature superconductor, $YBa_2Cu_3O_{7-\delta}$. The influence of processing parameters for YBCO thin films on MgO substrates in-situ grown by the pulsed laser deposition, including parameters of a laser beam energy, oxygen pressure, substrate temperature, target-substrate dis-tance is discussed. The characteristics of YBCO thin films were analyzed by using XRD, R-T measurement, AFM, crosssectional TEM, and RBS. For examples of microwave device applications, The fabrication and characterization of the microstrip lowpass filter and bandpass filter are also presented.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1994년도 추계학술대회 논문집
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• pp.54-58
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• 1994

H$_2$ bake and GeH$_4$ clean are used as a in-situ pre-clean method in low temperature Si based epitaxial growth technology using rapid thermal processing chemical vapor deposition (RTPCVD). In this paper, the H$_2$ bake and GeH$_4$ clean processes are optimized for low surface defect density using Taguchi method. In H$_2$ bake process, the epitaxial growth temperature affects dominantly on the surface defect density, and the next affecting factors are H$_2$ bake temperature and rinse time in de-ionised water. In GeH$_4$ clean process, GeH$_4$ clean temperature affects most strongly on the surface defect density, and the minor factor is GeH$_4$flow rate. The optimum process conditions predicted fly Taguchi method agree well with tile experimental data in both in-situ clean processes.

• 한국결정성장학회지
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• 제10권5호
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• pp.350-355
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• 2000

수평 Bridgeman방식으로 성장된 C축 방향의 사파이어 결정기판을 연마 가공하였으며, 또한 유기금속 기상화학 증착 방법으로 사파이어 기판 위에 GaN 박막을 증착하였다. 사파이어 인고트를 성장하여 2인치 사파이어 기판으로 이용하였으며 웨이퍼 절편장치 및 연마장치를 개발하였다. 이러한 다단계의 연마 가공은 기판 표면을 경면화하였다. 표면 평탄도 및 조도는 원자힘현미경으로 측정하였다. 개발된 사파이어 기판위에 성장된 GaN 박막의 특성 및 청색광소자로의 응용 가능성을 확인하였다.

• Journal of Korean Vacuum Science & Technology
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• 제4권3호
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• pp.63-67
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• 2000

We have studied the photoluminescence properties of undoped epitaxial layers of GaN on sapphire substrate grown by horizontal low pressure metal organic chemical vapor deposition method in the temperature range of 9-300 K. At 9 K the spectra are dominated by the well resolved interband free excitons A and B as well as bound excitons. Temperature dependence of free exciton transitions was studied and Varshni's coefficients for the temperature variation of bandgap were determined.

• 한국진공학회지
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• 제8권4B호
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• pp.519-523
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• 1999

Epitaxial thickness $t_e(T_s)$ of Si films grown at the substrate temperature $T_s$=80~30$0^{\circ}C$ by ultra-high vacuum ion-beam sputter deposition onto nominally-singular, [100]-miscut Si(001) was measured. $t_e(T_s)$ values of films grown on vicinal Si(001) substrates were decreases compared to those of films grown on nominally-singular Si(001). Evolution of surface roughness measured by atomic force microscopy of films grown at $300^{\circ}C$ showed that the increases step density in vicinal substrates increases the tendency toward unstable growth resulting in larger surface roughness, which in turn decreases te.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.395-395
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• 2012

We fabricate organic-inorganic hybrid thin film for the purpose of encapsulation by molecular layer deposition (MLD) using Trimethylaluminium (TMA) and Adipoyl Chloride (AC). Ellipsometry was employed to verify self limiting reaction of ALD. Linear relationship between number of cycle and thickness was obtained. We found that desirable organic thin film fabrication is possible by MLD surface reaction in nanoscale. Purging was carried out after dosing of each precursor to form monolayer in each sequence. We also confirmed roughness of the organic thin film by atomic force microscopy. We deposit TMA and AC at $70^{\circ}C$ and that 1.78A root mean square was obtained which indicates that uniform organic thin film was formed. We confirmed precursor's functional group by IR spectrum. We calculated WVTR of organic-inorganic hybrid super-lattice epitaxial layer using Ca test. WVTR indicates superlattice film can be possibly use as encapsulation in flexible devices.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 제5회 학술대회 논문집 일렉트렛트 및 응용기술연구회
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• pp.45-48
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• 2003

BiSrCaCuO thin films were fabricated by atomic layer-by-layer deposition using an ion beam sputtering method. 10 wt% and 90 wt% ozone mixed with oxygen were used with ultraviolet light irradiation to assist oxidation. At early stages of the atomic layer by layer deposition, two dimensional epitaxial growth which covers the substrate surface would be suppressed by the stress and strain caused by the lattice misfit, then three dimensional growth takes place. Since Cu element is the most difficult to oxidize, only Sr and Bi react with each other predominantly, and forms a buffer layer on the substrate in an amorphous-like structure, which is changed to $SrBi_2O_4$ by in-situ anneal.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 추계학술발표대회
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• pp.21.1-21.1
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• 2011

Vertically aligned single-crystal ZnO nanowires have been successfully grown on c-plane sapphire substrate using chemical vapor deposition (CVD) without catalyst. According to growth temperatures, it was changed ZnO growth characteristic. We investigated the effect of substrate temperatures on the growth ZnO films or nanowires on c-plane (0001) sapphire substrates. The ZnO films were acquired at $500^{\circ}C$, whereas the ZnO nanowires were obtained at $600^{\circ}C$, $700^{\circ}C$, and $800^{\circ}C$. The growth behavior diameter and growth rate of ZnO were changed due to different temperature. As a result of analyzing in-plane residual stress by X-ray diffraction, the optimized condition of ZnO nanowires were at $600^{\circ}C$.