• Title/Summary/Keyword: AlN crystals

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A study on the growth of AlN single crystals (AlN 단결정 성장에 관한 연구)

  • Kang, Seung-Min
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.23 no.6
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    • pp.279-282
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    • 2013
  • Recently, it has been interested much that AlN (Aluminum Nitride) crystals can be applied to UV LEDs and high power devices as like GaN and SiC crystals. The reports about commercial grade of AlN wafers in the world have been absent, however several results for growth of large size of AlN single crystals have been reported from abroad. In this report, the result of AlN single crystals of a diameter of about 8 mm grown are reported. Optical microscopic characterization was applied to observe the form of the crystals and the crystal quality was evaluated by FWHM measurement by DCXRD rocking curve analysis.

Morphological study on non-seeded grown AlN single crystals (무종자결정 상에 성장된 AlN 결정의 형태학적 연구)

  • Kang, Seung-Min
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.22 no.6
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    • pp.265-268
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    • 2012
  • The growth of AlN single crystals of large size and good quality is of prime importance for UV LEDs and power devices applications. However, the crystals having the size of more than 1 inch and high quality have not been reported in the world. In the PVT growth of AlN, the crystal morphology of as grown were important because the preferred orientation of growth of it was evaluated for growth rate increase. In the present study, the AlN single crystals grown by PVT process were evaluated by the side of the growth morphology. Optical microscopic characterization was carried out to observe the shape of the crystals and the growth facets. Furthermore the growth habit of it were discussed by observation of the surface of AlN crystals.

A study on the growth morphology of AlN crystals grown by a sublimation process (승화법으로 성장된 AlN 결정의 성장 양상에 관한 연구)

  • Kang, Seung-Min
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.19 no.5
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    • pp.242-245
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    • 2009
  • AlN crystals were grown by a sublimation process without seed crystals and the growth morphology of them was characterized. The grown AlN crystals were a polycrystalline phase, which had a diameter of $60\sim200\;{\mu}m$ and were grown with a growth rate of $0.2\sim0.5\;{\mu}n/hr$. It was observed that the as-grown crystals had a hexagonal crystal structure and revealed that these crystals were grown with a morphology of columnar morphology in the initial stage of the growth before they were enlarged in a way of a lateral growth behavior in the final stage. On the surface, a lot of pinholes were observed on the surface of crystals grown. The evolution of a growth morphology was characterized by optical and scanning electron microscopic observation.

Growth of AlN crystals by the sublimation process (승화법에 의한 AlN 결정의 성장)

  • Kang, Seung-Min
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.18 no.2
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    • pp.68-71
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    • 2008
  • AlN crystals were grown by the sublimation process. As grown AlN crystals were the polycrystalline boule in the form of the agglomerate of small AlN single crystalline AlN. As-grown AlN boule has a length about 2${\sim}$3 mm long and a diameter of 1 inch. The carbon impurities were observed on the surface and inside of the grown AlN crystals and the growth behavior was investigated by optical microscopy and SEM observation.

A study on the crystalline phases of AlN single crystals grown by PVT method (PVT 법으로 성장된 AlN 단결정의 결정상에 관한 연구)

  • Kang, Seung-Min
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.24 no.2
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    • pp.54-58
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    • 2014
  • AlN (Aluminum Nitride) crystals were grown by a PVT (Physical Vapor Transport) method and were characterized to phases on the growth temperature. The crystals phase and morphology were analyzed using an optical stereo-microscope and the optimum temperature for the growing was determined. In this report, the characteristics of the AlN crystals grown at various temperatures were reported.

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.

Synthesis of Aluminum Nitride from Metal Aluminum Powders (금속알루미늄으로부터 질화알루미늄의 합성)

  • 최상욱;이승제
    • Journal of the Korean Ceramic Society
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    • v.22 no.6
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    • pp.80-86
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    • 1985
  • Aluminum nitride (AlN) was synthesized from aluminum (Al) powders as a starting material in the tempe-rature range of 450~1, 15$0^{\circ}C$ in the presence of 90% $N_2$-10%$H_2$ gases. The thermogravimentric analysis showed that the nitridation of Al powders started at about 43$0^{\circ}C$ and escalated greatly from 53$0^{\circ}C$. The scanning electron microcopic observation revealed that AlN crystals were different in shape with varying temperature of nitridation. The crystals of AlN which were formed in the lower temperature than the melting point of Al were spherical while those of AlN in the higher temperature were fibrous. The yield of AlN was determined quantitatively by both XRD method and weight gain between before and after the nitridation of Al compacts. It was considered that the former was available for the specimen which was made in the high nitriding temperature. But the latter was unavilable for the same one probably because of the volatile loss of Al in the higher temperature.

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New Oxide Crystals as Substrates for GaN-based Blue Light Emitting Devices

  • Fukuda, T.;Shimamura, K.;Tabata, H.;Takeda, H.;Futagawa, N.;Yoshikawa, A.;Kochurikhin, Vladimir-V.
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1999.06a
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    • pp.3-26
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    • 1999
  • We have successfully grown <111>-oriented (La,Sr)(Al,Ta)$O_3$(LSAT) mixed-perovskite single crystals and <0001>-oriented $Ca_8La_2(PO_4)_6O_2$(CLPA) single crystals with the apatite structure by the Czochralski method. The compositional and lattice parameter uniformity of the crystals are discussed in relation to the growth conditions. Since LSAT and CLPA single crystals have excellent lattice matching with GaN, they ar promising as new substrates for the growth of high quality GaN epitaxial layers.

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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.

A study on the crystallinity of AlN single crystals by heat treatment (열처리에 따른 AlN 단결정의 결정성에 관한 연구)

  • Kang, Seung-Min
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.27 no.3
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    • pp.105-109
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    • 2017
  • AlN single crystal was thermally treated at $1200^{\circ}C$ and $1500^{\circ}C$ in the ambient gas of nitrogen. AlN single crystal was obtained by sublimation growth process using by a facility having a growth part which was heated by RF (Radio Frequency) induction heating. In this report, the optical microscopic results taken from thermally treated AlN single crystal and FWHM (Full width of half maximum) measured by DCXRD (Double crystal X-ray Diffractometry) were reported.