• Title/Summary/Keyword: bridgman method

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Growth of GaAs Single Crystal by Horizontal Bridgman method and Wetting (수평 Bridgman법에 의한 GaAs단결정 성장 및 Wetting에 관한 연구)

  • 강기문;홍봉식;한병성;온동만
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.35 no.1
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    • pp.1-7
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    • 1986
  • The GaAs bulk single crystals are grown by the Horizontal Bridgman method. During the growth, one of the problems in Bridgman method is the boat wetting between GaAs molten and silica boat. This boat wetting may result in another nucleation to form twin crystals. In this study, We find that the optimal size for sand blasting is 320 mesh. Backfilling the ampoule with argon gas during the vaccum bake-out decreaes the boat wetting. The reaction mechanism of Ga with quartz to produce suboxide, Ga2O, and sillion is discussed.

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Calculation of the amount of excess As charge for the GaAs single crystal growting with the horizontal Bridgman method of single temperature zone(1-T HB) (단일 온도대역 수평 Bridgman(1-T HB) 법에 의한 GaAs 단결정 성장시 As 원소의 초과 유입량 계산)

  • 오명환;주승기
    • Korean Journal of Crystallography
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    • v.7 no.1
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    • pp.64-72
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    • 1996
  • Calculation of the amount of excess arsenic charge has been carried out for the single crystal growth of GaAs with 1-T HB(single temperature zone horizontal Bridgman) method which has no low temperature arsenic zone. Based upon the investigation of the thermochemical properties of the Ga and As system, a general equation for the excess dimension of the ampoule and temperature gradient of the furnace. From this result, a theoretical background of the 1-T HB method has been constructed for the single crystal growth of GaAs.

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Growth of lead-based functional crystals by the vertical bridgman method

  • Xu Jiayue
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.16 no.1
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    • pp.1-7
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    • 2006
  • Some lead-based crystals show excellent ferroelectric, piezoelectric or scintillation properties and have attracted much attention in recent years. However, the erosion of the high temperature solution on platinum crucible and the evaporation of PbO component are the main problems often encountered during the crystal growth. In this paper, we reported recent progress on the Bridgman growth of lead-based functional crystals, such as novel relaxor ferroelectric crystals (PZNT and PMNT), scintillation crystals $(PbWO_4,\;PbF_2\;and\;PbClF)$ and piezoelectric crystals $(Pb_5Ge_3O_{11}\;and\;Pb_2KNb_5O_{15}),$ in Shanghai Institute of Ceramics, Chinese Academy of Sciences. The vertical Bridgman method has been modified to grow PZNT crystals from high temperature solution and as-grown crystals have been characterized. Large size lead-based scintillators, $PbWO_4\;and\;PbF_2$ crystals, have been mass-produced by the vertical Bridgman method in the multi-crucible fumace. These crystals have been supplied to CERN and other laboratories for high-energy physics experiments. The Bridgman growth of piezoelectric crystals $Pb_5Ge_3O_{11}\;and\;Pb_2KNb_5O_{15}$ are discussed also.

Analysis of silicon incorporation into the GaAs melt from the quartz boat during the single crystal growing with horizontal Bridgman method (수평 Bridgman 법에 의한 GaAs 단결정 성장시 석영 보트(boat)로부터의 Si 유입에 대한 분석)

  • 오명환;주승기
    • Korean Journal of Crystallography
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    • v.7 no.1
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    • pp.81-87
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    • 1996
  • The mechanism of silicon incorporation has been analyzed for the boat-grown GaAs crystals on the basis of phase equilibrium in the Ga and As system. Comparison was made between silicon concentrations calculated from the thermodynamics of incorporation reaction and carrier concentrations measured from van der Pauw method. For the 1-T HB(single temperature zone horizontal Bridgman) crystals, calculated concentrations were 5.3 ×10 15 (atoms/cm3), measured as 9.8 ×10 15(/cm3) at the seed part. They were calculated to be 1.1 ×10 16(atoms/cm3) and measured as 1.5 ×10 16(/cm3) for the 2-T(double temperature zone) HB crystals. On the other hand, it was found to be closer between the calculated and measured silicon concentrations for the VGF(vertical gradient freeze) crystals, which were grown within half the run time compared with 1-T or 2-T HB method.

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Optical and Electrical Property of $\beta$-Phases $In_2Te_3$ Single Crystal by Vertical Bridgman Method (수직 Bridgman법으로 제작한 $\beta-In_2Te_3$ 단결정의 광학적 전기적 특성)

  • Kim, Nam-Oh;Lee, Kang-Yeon;Jeong, Byeong-Ho;Choi, Youn-Ok;Shin, Hwa-Young;Cho, Geum-Bae
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.58 no.4
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    • pp.451-454
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    • 2009
  • The $\beta-In_2Te_3$ single crystal was grown by vertical Bridgman method. The $\beta-In_2Te_3$ single crystal had a face centered cubic(fcc) structure. The lattice constants were found to be $a\;=\;0.617\;{\AA}$. The direct optical energy gap ($E_g$) was found to be 1.11 ev at 300 K. Raman spectra peak of $\beta-In_2Te_3$ single crystal showed the low $E_{LO}$ mode at $105\;cm^{-1}$. The electrical conduction type was measured by the thermal method and was p-type. The electrical conductivity was found to be $1.8\;{\times}\;10^{-2}\;{\Omega}^{-1}cm^{-1}$ at 300 K. The activation energy was found to be 0.51 eV.

Analysis of thermal stress through finite element analysis during vertical Bridgman crystal growth of 2 inch sapphire (유한요소해석법을 이용한 2 inch 사파이어 vertical Bridgman 결정성장 공정 열응력 해석)

  • Kim, Jae Hak;Lee, Wook Jin;Park, Yong Ho;Lee, Young Cheol
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.25 no.6
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    • pp.231-238
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    • 2015
  • Sapphire single crystals have been highlighted for epitaxial of gallium nitride films in high-power laser and light emitting diode industries. Among the many crystal growth methods, vertical Bridgman process is an excellent commercial method for growing high quality sapphire crystals with c-axis. In this study, the thermally induced stress in Sapphire during the vertical Bridgman crystal growth process was investigated using a finite element model. A vertical Bridgman process of 2-inch Sapphire was considered for the model. The effects of vertical and transverse temperature gradients on the thermal stress during the process were discussed based on the finite element analysis results.

A study on the growth and electrical-optical characteristics of undoped-InSe and Sn-doped Inse single crystals by vertical bridgman method (수직 Bridgman법에 의한 InSe 단결정의 성장 및 Sn 도핑에 따른 전기.광학적 특성에 관한 연구)

  • 정희준;송필근;문동찬;김선태
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.481-484
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    • 1999
  • The undoped-InSe and Sn-doped InSe single crystals were grown by vertical Bridgman method and their properties were invesigated. These crystals were obtained by lowering the quartz ampoule for growth in the furnace and growth rate at optimum condition is 0.4mm/hr. The orientations and the crystallinites of these crystals were identified by X-ray diffraction(XRD), double crystal rocking curve(DCRC) and etch-pit density(EPD) measurements. From the Raman spectrum at room temperature, TO, LO modes together with their overtones and combinations were observed. Optical properties were investigated by photoluminescence at 12K and direct band gap of these crystals obtained from optical absorption spectrum. Compared with undoped-lnSe, electrical properties of Sn-doped InSe were increased and the electrical conductivity type were n-type. But electrical properties along growth direction of crystals and radial direction of wafer showed nearly uniform distribution.

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A study on the growth of undoped-lnSe single crystal by vertical Bridgman method and Zn diffusion in Sn-doped InSe (수직 Bridgman법에 의한 InSe 단결정의 성장 및 Sn이 첨가된 InSe에서 Zn의 확산에 잔한 연구)

  • 정회준;문동찬;김선태
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.464-467
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    • 1999
  • The undoped-InSe and Sn-doped InSe single crystals were grown by vertical Bridgman method and their properties were invesigated. The orientations and the crystallinites of these crystals were identified by X-ray diffraction(XRD), double crystal rocking curve(DCRC) and etch-pit density(EPD) measurements. From the Raman spectrum at room temperature, TO, LO modes and together with their overtones and combinations were observed. Optical properties were inves ated by PL at 12K and direct band gap of these crystals obtained from optical absorption spectrum. Compared with undo&-InSe, electrical properties of Sn-doped InSe were increased and the electrical conductivity type were n-type. But electrical properties along growth direction of crystals and radial direction of wafer showed nearly uniform distribution. The Zn diffusion mechanism in InSe could be explained by interstitial-substitutional and vacancy complex models and the activation energy of 1.15-3.01eV were needed for diffusion.fusion.

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