Journal of the Korean Crystal Growth and Crystal Technology (한국결정성장학회지)

The Korea Association of Crystal Growth (한국결정성장학회)
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Effect of VI/III ratio on properties of alpha-Ga2O3 epilayers grown by halide vapor phase epitaxy

HVPE 방법으로 성장된 alpha-Ga2O3의 특성에 대한 VI/III ratio 변화 효과

  • Son, Hoki (Korea Institute of Ceramic Engineering & Technology) ;
  • Choi, Ye-Ji (Korea Institute of Ceramic Engineering & Technology) ;
  • Lee, Young-Jin (Korea Institute of Ceramic Engineering & Technology) ;
  • Lee, Mi-Jai (Korea Institute of Ceramic Engineering & Technology) ;
  • Kim, Jin-Ho (Korea Institute of Ceramic Engineering & Technology) ;
  • Kim, Sun Woog (Korea Institute of Ceramic Engineering & Technology) ;
  • Ra, Yong-Ho (Korea Institute of Ceramic Engineering & Technology) ;
  • Lim, Tae-Young (Korea Institute of Ceramic Engineering & Technology) ;
  • Hwang, Jonghee (Korea Institute of Ceramic Engineering & Technology) ;
  • Jeon, Dae-Woo (Korea Institute of Ceramic Engineering & Technology)
  • Received : 2018.06.08
  • Accepted : 2018.06.12
  • Published : 2018.06.30
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Abstract

In this study, we report the effect of VI/III ratio on ${\alpha}-Ga_2O_3$ epilayer on sapphire substrate by halide vapor phase epitaxy. The surface of ${\alpha}-Ga_2O_3$ epilayer grown with various VI/III ratios was flat and crack-free. To analyze the optical properties of the ${\alpha}-Ga_2O_3$ epilayers, the transmittance and an optical band gap were measured. The optical band gap was shown to be around 5 eV and showed a proportional increase in VI/III ratios. To determine the crystal quality of alpha gallium oxide grown with a ratio of 23, closed to the theoretical optical band gap, the FWHM was measured by HR-XRD. The calculated dislocation density of screw and edge were $1.5{\times}10^7cm^{-2}$ and $5.4{\times}10^9cm^{-2}$, respectively.

본 연구에서는 HVPE 성장법을 이용하여 사파이어 기판 위에 알파 갈륨옥사이드를 성장시키며 VI/III 비의 변화에 따른 효과를 확인하였다. 성장된 알파 갈륨옥사이드의 표면은 평평하고 crack 없이 성장되었다. 성장된 갈륨옥사이드의 광학적 특성을 분석하기 위해 투과율을 측정하고 광학 밴드갭을 얻었다. 광학 밴드갭은 약 5.0 eV로 나타났고 VI/III 비가 증가함에 따라 비례하여 증가하는 결과를 보여주었다. 이론적 광학 밴드갭에 가장 근접한 VI/III 비가 23인 조건에서 성장된 알파 갈륨옥사이드의 결정성을 확인하기 위해 HR-XRD를 이용하여 FWHM을 측정하였고 이를 바탕으로 전위밀도를 계산하였을 때 나선형 전위밀도는 $1.5{\times}10^7cm^{-2}$, 칼날 전위 밀도는 $5.4{\times}10^9cm^{-2}$로 계산되었다.

Keywords

References

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