• 한국결정성장학회지
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• 제14권4호
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• pp.140-144
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• 2004

Hot-wall epitaxy법으로 GaAs 기판 위에 성장시킨 CdTe 박막은 (III) 면의 단결정 박막으로 성장되었음을 XRD 측정으로부터 확인하였으며, 박막 성장률은 SEM 측정 사진으로부터 30 $\AA/s$임을 알았다. PL 측정으로 얻은 최적성장조건은 원료물질 온도 $500^{\circ}C$, 기판 온도 $320^{\circ}C$이었다.

• 대한전자공학회논문지
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• 제23권6호
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• pp.820-832
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• 1986

In contrast to conventional liquid phase epitaxy of GaAs, surface kinetics limited growth is predominant in selective liquid phase epitaxy. For the stripe openings in the high-index crystal-lographic directions, the well-known facet formations and the decompositions into the low index planes or smooth circular surfaces are observed depending on the growth kinetics. For the low index direction stripe, surface kinetics limited growth is evident. By a numerical calcualtion we show that these phenomena are due to the enhanced masstransport by two dimensional diffusion and growth rate anisotropy which is found to be very stdrong with cusped minima for some singular planes in the solution growth as well as in vapor phase epitaxy. Morphological stability is briefly treated in terms of diffusion and its implications on device application are stated. Tese phenomena may be common to III-V compound semiconductors as well as GaAs.

• 한국진공학회지
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• 제18권6호
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• pp.468-473
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• 2009

Chemical beam epitaxy 성장법으로 InP/InGaAs 다층구조의 선택적 영역 에피성장 (selective area epitaxy)을 하였다. <011> 방향에 평행한 직선패턴에서는 선폭이 작아지고, <01-1> 방향에 평행한 직선패턴에서는 선폭이 증가하는 현상이 나타났는데 이는 InGaAs의 <311>A와 B면이 <01-1> 방향에 평행한 직선패턴에서 성장되었기 때문으로 설명되었다. 성장속도가 $1\;{\mu}m/h$인 조건에서 5족 가스의 압력이 감소할수록 (100) 면 위에서 평평한 에피층이 성장되었는데 이는 5족 가스의 과포화현상에 의한 3족 원소의 표면이동으로 설명하였다.

• 한국진공학회지
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• 제5권3호
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• pp.199-205
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• 1996

InGaAs 박막의 facet 성장을 연구하기 위하여 triethygallium(TEGa), trimethylindium (TMIn)과 사전 열분해하지 않은 monoethylarsine (MEAs)을 사용하여 chemical beam epitaxy (CBE) 법으로 InGaAs 박막을 선택적으로 성장시켰다. 성장 온도와 패턴의 방향에 따라 facet 형성이 매우 다르게 나타났다. 마스크를 [11] 방향으로 제작한 기판에서는 facet의 면이 (311), (377)과 (11)의 여러 면이 형성되었으나 성장 온도가 올라감에 따라 (311)한 면으로 발전하였다. 또한 마스크를 [011]방향으로 하였을 때는, 성장 온도가 증가함에 따라 facet은 (11)h가 (111)면에서 (111)면으로 변하였다. 이러한 결과들은 측면에서 원료가스의 표면 이동 거리가 성장 온도에 따라서 변화하는 차이에 기인하는 것으로 믿어진다. U자 형태를 가지는 (100)의 윗면은 간단한 dangling bond 모형으로 설명할수 있었다.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2009년도 정기총회 및 동계학술연구발표회
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• pp.190-190
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• 2009

We report the epitaxial growth of MgO and CoFe/MgO on Ge (001) substrates using molecular beam epitaxy. It was found that the epitaxial growth of a MgO film on Ge could be realized at a low growth temperature of $125{\pm}5^{\circ}C$ and the MgO matches the Ge with a cell ratio of $\sqrt{2}$:1 which renders MgO rotated by $45^{\circ}$ relative to Ge. In-situ and ex-situ structural characterizations reveal the epitaxial crystal growth of bcc CoFe/MgO on Ge with the in-plane crystallographic relationship of CoFe(001)[100] || MgO(001)[110] || Ge(001)[100], exhibiting sharp interfaces in the (001) matching planes. The saturation magnetization of the sample is $1430{\pm}20$ emu/cc, which is comparable to the value of bulk CoFe.

• 한국인쇄학회지
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• 제22권2호
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• pp.151-162
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• 2004

MnSb layers were grown on GaAs(100), (111)A and (111)B substrates by hot wall epitaxy under various growth conditions. Growth condition dependence of structural properties of the layers was examined. The growth direction and structural properties of MnSb/GaAs(100) depend on Sb source and substrate temperatures. The smooth MnSb(10.1)/GaAs(100) interface was obtained under the appropriate growth condition. On the other hand, MnSb(00.1) layers were grown on GaAs(111) substrates. The quality of the layers on (111)B was superior to that on GaAs(111)A, but degraded as in increasing Sb source temperature during the growth. The $Mn_2Sb$ domain was generated in the layers grown under conditions of low Sb source temperature and high substrate temperature on GaAs(111) substrates.

• 한국재료학회지
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• 제12권4호
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• pp.304-307
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• 2002

A zinc oxide (ZnO) single crystal was used as a substrate in the hydride vapor-phase epitaxy (HVPE) growth of GaN and the structural and optical properties of GaN layer were characterized by x- ray diffraction, transmission electron microscopy, secondary ion mass spectrometry, and photoluminescence (PL) analysis. Despite a good lattice match and an identical structure, ZnO is not an appropriate substrate for application of HVPE growth of GaN. Thick film could not be grown. The substrate reacted with process gases and Ga, being unstable at high temperatures. The crystallinity of ZnO substrate deteriorated seriously with growth time, and a thin alloy layer formed at the growth interface due to the reaction between ZnO and GaN. The PL from a GaN layer demonstrated the impurity contamination during growth possibly due to the out-diffusion from the substrate.

• 한국표면공학회지
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• 제23권4호
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• pp.197-207
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• 1990

Atomic layer epitaxy is a relatively new epitaxial pprocess chracterized by the alternate and separate exposure of a susbstrate surface to the reactants contaning the constituent element of a compound semicoductror. The ideal ALE is expected to provide sevral advantageous as petcts for growing complicated heterostrutures such as relativly easy controls of the layer thinkness down to a monolayer and in forming abrupt heterointerfaces though monolayer self-saturatio of the growth. In addition, since ALE is stongly dependent on the surface reaction, the growth can also be controlled by photo-excitation which provides activation can be energies for each step of the reaction paths. The local growth acceleration by photo-excitation can be exploited for growing several device strures on the same wafer, which provides another important practical advantage. The ALE growth of GaAs has advanced to the point the laser opertion has been achieved from AlGs/GaAs quantun well structures where thee active layers were grown by thermal and Ar-laser assisted ALE. The status of the ALE growth of GaAs and other III-V compounds will be reviewed with respect to the growth saturation behavior and the electrical properties of the grown crystals.

• 한국재료학회지
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• 제22권10호
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• pp.539-544
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• 2012

We have grown AlN nanorods and AlN films using plasma-assisted molecular beam epitaxy by changing the Al source flux. Plasma-assisted molecular beam epitaxy of AlN was performed on c-plane $Al_2O_3$ substrates with different levels of aluminum (Al) flux but with the same nitrogen flux. Growth behavior of AlN was strongly affected by Al flux, as determined by in-situ reflection high energy electron diffraction. Prior to the growth, nitridation of the $Al_2O_3$ substrate was performed and a two-dimensionally grown AlN layer was formed by the nitridation process, in which the epitaxial relationship was determined to be [11-20]AlN//[10-10]$Al_2O_3$, and [10-10]AlN//[11-20]$Al_2O_3$. In the growth of AlN films after nitridation, vertically aligned nanorod-structured AlN was grown with a growth rate of $1.6{\mu}m/h$, in which the growth direction was <0001>, for low Al flux. However, with high Al flux, Al droplets with diameters of about $8{\mu}m$ were found, which implies an Al-rich growth environment. With moderate Al flux conditions, epitaxial AlN films were grown. Growth was maintained in two-dimensional or three-dimensional growth mode depending on the Al flux during the growth; however, final growth occurred in three-dimensional growth mode. A lowest root mean square roughness of 0.6 nm (for $2{\mu}m{\times}2{\mu}m$ area) was obtained, which indicates a very flat surface.

• Journal of Magnetics
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• 제10권3호
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• pp.108-112
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• 2005

GaAs nanowires were grown on GaAs (111)B substrates in a gas source molecular beam epitaxy system, using self-assembled Au particles with diameters between 25 and 200 nm as the catalytic agents. The growth rate and structure of the nanowires were investigated for substrate temperatures between 500 and $600^{\circ}C$ to study the mass transport mechanisms that drive the growth of these crystals. The possibilities for fabrication of novel magnetic nanostructures by suitable choice of growth conditions are discussed.