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

The Korea Association of Crystal Growth (한국결정성장학회)
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Microstructure analyses of aluminum nitride (AlN) using transmission electron microscopy (TEM) and electron back-scattered diffraction (EBSD)

투과전자현미경과 전자후방산란회절을 이용한 AlN의 미세구조 분석

  • Joo, Young Jun (Div. of Materials Engineering & Convergence Technology, Gyeongsang National Univ.) ;
  • Park, Cheong Ho (Div. of Materials Engineering & Convergence Technology, Gyeongsang National Univ.) ;
  • Jeong, Joo Jin (Dept. of Nano & Advanced Materials Engineering, Gyeongsang National Univ.) ;
  • Kang, Seung Min (Dept. of Advanced Science and Engineering, Hanseo, Univ.) ;
  • Ryu, Gil Yeol (Research Institute of Industrial Science and Technology, Analysis and Assessment Group) ;
  • Kang, Sung (Research Institute of Industrial Science and Technology, Analysis and Assessment Group) ;
  • Kim, Cheol Jin (Research Institute of Green Energy Convergence Technology, Gyeongsang National Univ.)
  • 주영준 (경상대학교, 나노신소재융합공학과) ;
  • 박청호 (경상대학교, 나노신소재융합공학과) ;
  • 정주진 (경상대학교, 세라믹공학과) ;
  • 강승민 (한서대학교, 신소재공학과) ;
  • 류길열 ((재)포항산업과학연구원, 분석평가그룹) ;
  • 강성 ((재)포항산업과학연구원, 분석평가그룹) ;
  • 김철진 (경상대학교, 그린에너지융합연구소)
  • Received : 2015.07.31
  • Accepted : 2015.08.07
  • Published : 2015.08.31
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Abstract

Aluminum nitride (AlN) single crystals have attracted much attention for a next-generation semiconductor application because of wide bandgap (6.2 eV), high thermal conductivity ($285W/m{\cdot}K$), high electrical resistivity (${\geq}10^{14}{\Omega}{\cdot}cm$), and high mechanical strength. The bulk AlN single crystals or thin film templates have been mainly grown by PVT (sublimation) method, flux method, solution growth method, and hydride vapor phase epitaxy (HVPE) method. Since AlN suffers difficulty in commercialization due to the defects that occur during single crystal growth, crystalline quality improvement via defects analyses is necessary. Etch pit density (EPD) analysis showed that the growth misorientations and the defects in the AlN surface exist. Transmission electron microscopy (TEM) and electron back-scattered diffraction (EBSD) analyses were employed to investigate the overall crystalline quality and various kinds of defects. TEM studies show that the morphology of the AlN is clearly influenced by stacking fault, dislocation, second phase, etc. In addition EBSD analysis also showed that the zinc blende polymorph of AlN exists as a growth defects resulting in dislocation initiator.

AlN 단결정은 넓은 밴드갭(6.2 eV), 높은 열 전도도($285W/m{\cdot}K$), 높은 비저항(${\geq}10^{14}{\Omega}{\cdot}cm$), 그리고 높은 기계적 강도와 같은 장점들 때문에 차세대 반도체 적용을 위한 많은 흥미를 끈다. 벌크 AlN 단결정 또는 박막 템플릿(template)들은 주로 PVT(Physical vapor transport)법, 플럭스(flux)법, 용액 성장(solution growth)법, 그리고 증기 액상 증착(HVPE)법에 의해 성장된다. 단결정이 성장하는 동안에 발생하는 결함들 때문에 상업적으로 어려움을 갖게 된 이후로 결함들 분석을 통한 결정 품질 향상은 필수적이다. 격자결함 밀도(EPD)분석은 AlN 표면에 입자간 방위차와 결함이 존재하고 있는 것을 보여준다. 투과전자현미경(TEM)과 전자후방산란회절(EBSD)분석은 전체적인 결정 퀄리티와 다양한 결함의 종류들을 연구하는데 사용된다. 투과전자현미경(TEM)관찰로 AlN의 형태가 적층 결함, 전위, 이차상 등에 의해 크게 영향을 받는 것을 알 수 있었다. 또한 전자후방산란회절(EBSD)분석은 전위의 생성을 유도하는 성장 결함으로서 AlN의 zinc blende 폴리모프(polymorph)가 존재하고 있는 것을 나타내고 있었다.

Keywords

References

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