• Title/Summary/Keyword: Vapor phase epitaxy method

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Characteristics of Free-Standing GaN Substrates grown by Hydride Vapor Phase Epitaxy (Hydride Vapor Phase Epitaxy 법으로 성장된 Free-Standing GaN 기판의 특성에 관한 연구)

  • Kim, Hwa-Mok;Choe, Jun-Seong;O, Jae-Eung;Yu, Tae-Gyeong
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.37 no.3
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    • pp.14-19
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    • 2000
  • Free-standing GaN single crystal substrates have been obtained by growing thick GaN epitaxial layers on (0001) sapphire substrates using hydride vapor phase epitaxy (HVPE) method. After growing the GaN thick film of 200 ${\mu}{\textrm}{m}$, a free-standing GaN with a size of 10 mm $\times$10 mm were obtained by mechanical polishing process to remove sapphire substrate. Crack-free GaN substrates have been obtained by GaCl pre-treatment prior to the growth of GaN epitaxial layers. Properties of free-standing GaN substrates have been compared with those of lateral epitaxial overgrowth (LEO) GaN films by double-crystal x-ray diffraction (DC-XRD), cathodoluminescence (CL) and photoluminescence (PL) measurements.

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Growth and Properties of GaN on $\textrm{MgAl}_{2}\textrm{O}_{4}$ Substrate by Hydride Vapor Phase Epitaxy Method ($\textrm{MgAl}_{2}\textrm{O}_{4}$ 기판위에 GaN의 Hydride Vapor Phase Epitaxy성장과 특성)

  • Lee, Yeong-Ju;Kim, Seon-Tae;Kim, Bae-Yong;Hong, Chang-Hui
    • Korean Journal of Materials Research
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    • v.7 no.8
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    • pp.707-713
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    • 1997
  • HVPE(hydride vapor phase epitaxy)법으로 (111)MgAI$_{2}$ $O_{4}$기판위에 GaN 후막을 성장하였다. GaN를 성장하기 전에 기판에 표면을 GaCI로 처리한 수 성장하였을 때 이중 X선 회절 피크의 반치폭이 710 arcsec로서 N $H_{3}$로 처리한 후 성장한 GaN에 비하여 작았으며, 무색 투명의 경면상태가 얻어\ulcorner다. 113$0^{\circ}C$의 온도에서 성장한 GaN 의 광루미네센스(PL)특성과 동일하게 나타났다. 10K의 온도에서 측정된 PL 스펙트럼은 자유여기자와 속박여기자의 재결합천이에 의한 피크들과 Mg과 관련된 도너-억셉터 쌍 사이의 재결합 및 이의 1LO, 2LO, 3LO 및 4 LO 포논복제에 의한 피크들이 나타났다. 성장된 GaN는 n형의 전도성을나타내었으며, 캐리어 이동도와 농도는 각각 21.3$\textrm{cm}^2$/V ㆍsec와 4.2 x $10^{18}$$cm^{-3}$이었다.

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A Study on Solid-Phase Epitaxy Emitter in Silicon Solar Cells (고상 성장법을 이용한 실리콘 태양전지 에미터 형성 연구)

  • Kim, Hyunho;Ji, Kwang-Sun;Bae, Soohyun;Lee, Kyung Dong;Kim, Seongtak;Park, Hyomin;Lee, Heon-Min;Kang, Yoonmook;Lee, Hae-Seok;Kim, Donghwan
    • Current Photovoltaic Research
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    • v.3 no.3
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    • pp.80-84
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    • 2015
  • We suggest new emitter formation method using solid-phase epitaxy (SPE); solid-phase epitaxy emitter (SEE). This method expect simplification and cost reduction of process compared with furnace process (POCl3 or BBr3). The solid-phase epitaxy emitter (SEE) deposited a-Si:H layer by radio-frequency plasma-enhanced chemical vapor deposition (RF-PECVD) on substrate (c-Si), then thin layer growth solid-phase epitaxy (SPE) using rapid thermal process (RTP). This is possible in various emitter profile formation through dopant gas ($PH_3$) control at deposited a-Si:H layer. We fabricated solar cell to apply solid-phase epitaxy emitter (SEE). Its performance have an effect on crystallinity of phase transition layer (a-Si to c-Si). We confirmed crystallinity of this with a-Si:H layer thickness and annealing temperature by using raman spectroscopy, spectroscopic ellipsometry and transmission electron microscope. The crystallinity is excellent as the thickness of a-Si layer is thin (~50 nm) and annealing temperature is high (<$900^{\circ}C$). We fabricated a 16.7% solid-phase epitaxy emitter (SEE) cell. We anticipate its performance improvement applying thin tunnel oxide (<2nm).

A study on the growth behavior of AlN single crystal according to the change of N2 in HVPE propcess (HVPE(Hydride Vapor Phase Epitaxy) 법을 적용한 N2 양의 변화에 따른 AlN 단결정의 성장 거동에 관한 연구)

  • Kyung-Pil Yin;Seung-Min Kang
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.34 no.2
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    • pp.61-65
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    • 2024
  • HVPE (Hydride vapor phase epitaxy) is a method of manufacturing thin films or single crystals using gaseous raw materials. This is a method that applies the principles of chemical vapor deposition to grow a single crystal of a material with low meltability or high melting point, and is one of the methods that can obtain a gallium nitride (GaN) single crystal. Recently, much research has been conducted to grow aluminum nitride (AlN) single crystals using this method, but good results have not yet been obtained. In this study, we attempted to grow AlN single crystals using the HVPE method. Nitrogen was used as a carrier gas in the growth process, and the growth results according to changes in the amount of nitrogen (N2) were examined. Changes in growth crystals as the amount of nitrogen increased were confirmed. The shape of the grown AlN single crystal was observed using an optical microscope, and the rocking curve was measured using double crystal X-ray diffractometry (DCXRD) to confirm the creation of the AlN crystal. The crystallinity of single crystals was also investigated.

Direct synthesis mechanism of amorphous $SiO_x$ nanowires from Ni/Si substrate (Ni/Si 기판을 사용하여 성장시킨 비결정질 $SiO_x$ 나노 와이어의 성장 메커니즘)

  • Song, W.Y.;Shin, T.I.;Lee, H.J.;Kim, H.;Kim, S.W.;Yoon, D.H.
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.16 no.6
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    • pp.256-259
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    • 2006
  • The amorphous $SiO_x$ nanowires were synthesized by the vapor phase epitaxy (VPE) method. $SiO_x$ nanowires were formed on silicon wafer of temperatures ranged from $800{\sim}1100^{\circ}C$ and nickel thin film was used as a catalyst for the growth of nanowires. A vapor-liquid-solid (VLS) mechanism is responsible for the catalyst-assisted amorphous $SiO_x$ nanowires synthesis in this experiment. The SEM images showed cotton-like nanostructure of free standing $SiO_x$ nanowires with the length of more than about $10{\mu}m$. The $SiO_x$ nanowires were confirmed amorphous structure by TEM analysis and EDX spectrum reveals that the nanowires consist of Si and O.

Crystal Structure and Optical Property of Single-Phase (1210) Gallium Nitride Film ((1210) Gallium Nitride 단결정 박막의 결정구조 및 광학적 특성)

  • Hwang Jin Soo;Chong Paul Joe
    • Korean Journal of Crystallography
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    • v.8 no.1
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    • pp.33-37
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    • 1997
  • The optical properties of (1210) GaN epitaxy films grown on the (1012) $\alpha-A1_2O_3$ substrates have been studied. The hetero-epitaxy films were grown by the halide vapor phase epitaxy (HVPE) method using $Ga/HC1/NH_3/He$ system at $990^{\circ}C$. XRD, RHEED and SEM are used for the identification of the hetero-epitaxy films structure and surface morphology. The confirmed (1210) GaN epitaxy films were characterized by PL and Raman. By the Raman scattering, the active phonon modes of single-phase GaN films are varied with the arrangement of both polarization and propagation directions of laser beam with reference to the axis in single-phase crystal films. The Y(Z, Y & Z) X geometry allows scattering pat-terns of $A_1(TO)=533\;cm^{-1},\;E_1(TO)=559\;cm^{-1}\;and\;E_2=568 cm^{-1}$ modes, whereas in the Z(Y, Y & Z) X geometry the only $E_2$ mode are observed.

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GaN Thin Flims Grown by CVPE(Chloride Vapor Phase Epitaxy) Method (CVPE(Chloride Vapor Phase Epitaxy)법에 의한 GaN 박막성장 연구)

  • 오태효;박범진
    • Korean Journal of Crystallography
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    • v.8 no.2
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    • pp.81-88
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    • 1997
  • We investigated the CVPE grown of GaN thin films on (0001) sapphire using the $GaCl_3$ and $NH_3$ as source gases. The growth temperatures are ranged 970 to $1040^{\circ}C$ with the various flow rate ratio of source gases. The nitridation treatment was performed using the $NH_3$ gas before the GaN deposition. The optimal growth conditions were determined to be; growth temperature of $1040^{\circ}C$, III/V flow rate ratio of 2, nitridation time of 3 min. The FWHM at the (0002) peak from the XRD analysis was shown to be 0.32 deg. for the sample grown under those conditions. The growth rate was about $40{\mu}m/hr$ at $1040^{\circ}C$.

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Synthesis of GaN by Direct Reaction Method and Vapor Phase Epitaxy (직접반응법에 의한 GaN의 한성과 기상에피텍시)

  • 김선태;문동찬
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1995.11a
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    • pp.71-73
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    • 1995
  • In this work, we synthsized GaN powders by the direct reactions of Ga with NH$_3$at the temperature range of 950∼1150$^{\circ}C$ and we growth the GaN thin films on Si and sapphire substrates using the synthesized GaN powders by the vapor phase epitaxy method. The synthesized powder had hexagonal crystal structures with lattice constants of a$\sub$0/=3.1895${\AA}$, c$\sub$0/=5.18394${\AA}$. The reaction rates of GaN were increased with both reaction time and temperature, however it did not depends on the flow rates of NH$_3$. The island type GaN crystals were grown on (0001) sapphire substrates and fast lateral growth of GaN on (111) Si substrate than sapphire was observed in our experiments.

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A study on the growth morphology of AlN single crystal according to the change in temperature using HVPE method (HVPE(Hydride Vapor Phase Epitaxy) 법을 적용한 온도 변화에 따른 AlN 단 결정의 성장 형상에 관한 연구)

  • Seung Min Kang;Gyong-Phil Yin
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.34 no.1
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    • pp.36-39
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    • 2024
  • As interest in power semiconductors is growing recently, research on device design and application using light energy gap materials such as SiC and GaN is being actively conducted. Because AlN single crystals have a larger energy gap than the above mentioned materials, research on high-power devices is also in progress, but commercialized wafers have not yet been reported, so research is needed. In this study, we applied the HVPE (Hydride vapor phase epitaxy) method to produce AlN single crystals and attempted to obtain bulk single crystals using our own manufacturing equipment. To this end, we would like to report the results of securing the growth conditions for single crystals. we would like to report on the change in the shape of the grown crystal according to the change in temperature.