• Title/Summary/Keyword: Ga source

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Diffusion Kinetics of Si in GaAs and Related Defect Chemistry (GaAs에서의 Si의 확산기구와 그에 관련된 격자 결함 화학)

  • Lee, Gyeong-Ho
    • ETRI Journal
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    • v.11 no.4
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    • pp.75-83
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    • 1989
  • The diffusion mechanism of Si in GaAs was investigated using different diffusion sources based on the Si-Ga-As ternary phase equilibria. The Si profiles are measured with secondary ion mass spectrometry and differ significantly for sources taken from the different phase fields in the ternary phase diagram. Neutral As vacancy diffusion is proposed for acceptor Si diffusion anneals using a Ga - Si - GaAs source. Donor Si diffusion using As - rich sources and a Si -GaAs tie line source shows concentration dependent diffusion behavior. Concentration dependent diffusion coefficients of donor Si for As - rich source diffusion were found to be related to net ionized donor concentration and showed three regimes of different behavior: saturation regime, intermediate regime,and intrinsic regime. Ga vacancies are proposed to be responsible for donor Si diffusionin GaAs: $Si_Ga^+V_Ga^-$ (donor Si -acceptor Gavacancy) complex for the extrinsic regime and neutral $V_G$a, for the intrinsic regime.The Si - GaAs tie line source resulted in two branch profiles, intermediate between the As - rich and the Ga - rich source diffusion cases.

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Growth of InGaN on sapphire by GSMBE(gas source molecular beam epitaxy) using $DMH_y$(dimethylhydrazine) as nitrogen source at low temperature (Nitrogen source로 암모니아, $DMH_y$(dimethylhydrazine)을 사용해 Gas-Source MBE로 성장된 InGaN 박막특성)

  • Cho, Hae-Jong;Han, Kyo-Yong;Suh, Young-Suk;Park, Kang-Sa;Misawa, Yusuke
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07b
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    • pp.1010-1014
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    • 2004
  • High quality GaN layer and $In_xGa_{1-x}N$ alloy were obtained on (0001)sapphire substrate using ammonia$(NH_3)$ and dimethylhydrazine$(DMH_y)$ as a nitrogen source by gas source molecular hem epitaxy(GSMBE) respectively. As a result, RHEED is used to investigate the relaxation processes which take place during the growth of GaN and $In_xGa_{1-x}N$. The full Width at half maximum of the x-ray diffraction(FWHM) rocking curve measured from Plane of GaN has exhibitted as narrow as 8 arcmin. Photoluminescence measurement of GaN and $In_xGa_{1-x}N$ were investigated at room temperature, where the intensity of the band edge emission is much stronger than that of deep level emission. In content of $In_xGa_{1-x}N$ epitaxial layer according to growth condition was investigated.

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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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Characterization of In(Al)GaN layer grown by mixed-source hydride vapor phase epitaxy (혼합소스 HVPE에 의해 성장된 In(Al)GaN 층의 특성)

  • Hwang, S.L.;Kim, K.H.;Jang, K.S.;Jeon, H.S.;Choi, W.J.;Chang, J.H.;Kim, H.S.;Yang, M.;Ahn, H.S.;Bae, J.S.;Kim, S.W.
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.16 no.4
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    • pp.157-161
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    • 2006
  • InGaN layers on GaN templated sapphire (0001) substrates were grown by mixed-source hydride vapor phase epitaxy (HVPE) method. In order to get InGaN layers, Ga-mixed In metal and $NH_3$ gas were used as group III and group V source materials, respectively. The InGaN material was compounded from chemical reaction between $NH_3$ and indium-gallium chloride farmed by HCl flowed over metallic In mixed with Ga. The grown layers were confirmed to be InGaN ternary crystal alloys by X-ray photoelectron spectroscopy (XPS). In concentration of the InGaN layers grown by selective area growth (SAG) method was investigated by the photoluminescence (PL) and cathodoluminescence (CL) measurements. Indium concentration was estimated to be in the range 3 %. Moreover, as a new attempt in obtaining InAlGaN layers, the growth of the thick InAlGaN layers was performed by putting small amount of Ga and Al into the In source. We found the new results that the metallic In mixed with Ga (and Al) as a group III source material could be used in the growth process of the In(Al)GaN layers by the mixed-source HVPE method.

Distance between source and substrate and growth mode control in GaN nanowires synthesis (Source와 기판 거리에 따른 GaN nanowires의 합성 mode 변화 제어)

  • Shin, T.I.;Lee, H.J.;Kang, S.M.;Yoon, D.H.
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.18 no.1
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    • pp.10-14
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    • 2008
  • We synthesized GaN nanowires with high quality using the vapor phase epitaxy technique. The GaN nanowires were obtained at a temperature of $950^{\circ}C$. The Ar and $NH_3$ flow rates were 1000 sccm and 50 sccm, respectively. The shape of the GaN nanowires was confirmed through FESEM analysis. We were able to conclude that the GaN nanowires synthesized via vapor-solid (VLS) mechanism when the source was closed to the substrate. On the other side, the VS mechanism changed to vapor-liquid-solid (VLS) as the source and the substrate became more distant. Therefore, we can suggest that the large amount of Ga source from initial growth interrupt the role of catalyst on the substrate.

Semiconductor Nanowires;Their Emission Stability and Energy Distribution

  • Yu, Se-Gi;Yi, Whi-Kun;Lee, Sang-Hyun;Heo, Jung-Na;Jeong, Tae-Won;Lee, Jeong-Hee;Lee, Soo-Chang;Kim, J.M.;Lee, Cheol-Jin;Lyu, Seung-Chul;Han, Jae-Hee;Yoo, Ji-Beom
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.1028-1031
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    • 2002
  • Ga-based semiconductor nanowires (GaN, GaP) were synthesized by the reaction of Ga metal and GaN/GaP powder with a $NH_3/Ar$ gas using thermal chemical vapor deposition. The field emission and emission stability under oxygen and argon environments were investigated. Field emission energy distributions of electrons from these nanowires revealed that field emission mechanism of the semiconductor nanowires were different from carbon nanotubes.

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Growth and Properties of GaN Thin-Films Using Ionized N-Source (이온화된 N-source를 사용한 GaN박막의 성장과 특성)

  • Kim, Seon-Tae;Lee, Yeong-Ju
    • Korean Journal of Materials Research
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    • v.8 no.3
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    • pp.229-237
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    • 1998
  • We grew the hexagonal GaN films on (100) Si and (00.1) sapphire substrates in the temperature range of $300~730^{\circ}C$ by the direct reaction between thermally ionized N-source and thermally evaporated Ga-source. The GaN growth rates are increased at the initial stage of GaN formation and it was saturated to some values by the coalescence of each crystallites. The oxygen signal was observed in XPS spectra for all the GaN films grown in this work, especially low- temperature grown GaN film may due to incorporation of the residual oxygen in the growth chamber. The surface of low-temperature and shorter time grown films covered only Ga-droplets. however, with increasing the both substrate temperature and the growth time GaN is growth to crystallites. and coalescence to ring-type crystallites. With sufficient supply of N-source, they were changed to platelets. In the PL spectrum measured at 20 K, we observed the impurity related emission at 3.32eV and 3.38eV.

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HVPE growth of GaN/InGaN heterostructure on r-plane sapphire substrate (R-plane 사파이어 기판위의 GaN/InGaN 이종접합구조의 HVPE 성장)

  • Jeon, H.S.;Hwang, S.L.;Kim, K.H.;Jang, K.S.;Lee, C.H.;Yang, M.;Ahn, H.S.;Kim, S.W.;Jang, S.H.;Lee, S.M.;Park, G.H.;Koike, M.
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.17 no.1
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    • pp.6-10
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    • 2007
  • The a-plane GaN layer on r-plane $Al_2O_3$ substrate is grown by mixed-source hydride vapor phase epitaxy (HVPE). The GaN/InGaN heterostructure is performed by selective area growth (SAG) method. The heterostructure consists of a flown over mixed-sourec are used as gallium (or indium) and nitrogen sources. The gas flow rates of HCl and $NH_3$ are maintained at 10 sccm and 500 sccm, respectively. The temperatures of GaN source zone is $650^{\circ}C$. In case of InGaN, the temperature of source zone is $900^{\circ}C$. The grown temperatures of GaN and InGaN layer are $820^{\circ}C\;and\;850^{\circ}C$, respectively. The EL (electroluminescence) peak of GaN/InGaN heterostructure is at nearly 460 nm and the FWHM (full width at half maximum) is 0.67 eV. These results are demonstrated that the heterostructure of III-nitrides on r-plane sapphire can be successfully grown by mixed-source HVPE with multi-sliding boat system.

Power Supply for White GaN LED by Using SMD Type Solar Cell Array (SMD 타입 태양전지 어레이를 이용한 white GaN LED용 전원 공급 장치)

  • Kim, Seong-Il;Lee, Yoon-Pyo
    • New & Renewable Energy
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    • v.5 no.4
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    • pp.34-37
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    • 2009
  • Using six SMD(surface mount device) type AlGaAs/GaAs single junction solar cells connected in series, a power source was fabricated for a white GaN LED. The electrical properties of the power source was measured and analyzed under one sun (100mW/$cm^2$) and various indoor light (300 - 900 lux) conditions. Under 600 lux indoor light condition, output power was 17.06 ${\mu}W$ and it was 30.75 ${\mu}W$ under 900 lux indoor light condition. Using the fabricated solar cell power supply, we have turned on the white GaN LED. It was worked well under 15 ${\mu}W$(at 480 lux) power supplied from solar cell array. This kind of solar cell power supply can be used as a power source for ubiquitous sensor network (USN).

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Effect of trimethyl-indium source depletion on InGaAsP epilayer grown by MOCVD (Trimethyl-indium 소스 고갈에 따른 InGaAsP 에피층의 특성 변화)

  • 김현수;오대곤;편광의;최인훈
    • Journal of the Korean Vacuum Society
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    • v.9 no.4
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    • pp.400-405
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    • 2000
  • We investigated the effect of TMIn (trimethly-indium) source depletion on InGaAs, InGaAsP and 1.55 $\mu\textrm{m}$ InGaAs/InGaAsP SMQW by using EPISON ultrasonic monitor for measuring the concentration of metalorganic/carrier gas mixtures. And the problems for the growth reproducibility in MOCVD was solved by using an EPISON ultrasonic monitor with closed-loop mode under the condition of TMIn source depletion. The saturation pressure of TMIn was dramatically decreased over consumption of 80%. In the case of bulk epilayer, Up-shifting of 300 arcsec to Ga-rich direction and FWHM broadening by a factor of two in DCXRD spectrum were observed due to the TMIn source depletion. In the case of SMQW, Up-shifting of 300 arcsec to Ga-rich direction in DCXRD spectrum and blue-shift of 40 nm in PL spectrum were observed due to the TMIn source depletion. However, good reproducibility ($\Delta\theta$<$\pm$100 arcsec) was achieved even the condition of 95% of TMIn consumption, when we used the EPISON with closed-loop mode.

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