HVPE법으로 성장시킨 GaN substrate 제작과 특성 평가
Fabrication and characterization of GaN substrate by HVPE
0
조회
0
다운로드
2
인용
0
참고문헌
키워드
초록
본 연구에서는 HVPE을 이용하여 sapphire(001) 기판 위에 직경 2 inch, 두께 약 1.5 mm인 bulk GaN를 성장하고,이를 mechanical polishing을 통해 10 × 10, 15 × 15 mm 크기의 free-standing GaN template을 제작하여 그 특성을 평가하였다. 성장된 GaN 단결정의 X-ray diffraction pattern 결과 (002) 및 (004) 면으로부터의 회절에 의한 peak가 나타났으며, (002) 면의 DCXRD(Double crystal X-Ray diffraction) rocking curve peak의 반치폭(FWHM)은 98 arcsec으로 나타났다. 제작한 GaN template는 363 nm 파장에서 sharp한 PL spectrum을 나타내었으며, 불순물 defect에 의한 yellow 영역에서의 broad peak은관찰되지 않았으며, 제작된 GaN template표면의 etch-pit 밀도는 5 × 106/cm 2으로 매우 낮았다. 이러한 분석결과를 통하여 성장된 GaN template는 LED 및 LD 등의 청색 발광소자 및 고온, 고출력 소자용 기판재료로 응용이 가능할 것으로 생각 된다.
Abstract
Bulk GaN single crystal with 1.5 mm thickness was successfully grown by hydride vapor phase epitaxy (HVPE)technique. Free-standing GaN substrates of 10 × 10, 15 × 15 mm size were fabricate after lift-off of sapphire substrate and their optical properties were characterized properties for device applications. X-ray diffraction patterns showed (002) and (004) peak, and the FWHM of the X-ray rocking curve (XRC) measurement in (002) was 98 arcsec. A sharp photoluminescence spectrum at 363 nm was observed and defect spectrum at visible range was not detected. The hexagonal-shaped etch-pits are formed on the GaN surface in 200oC H3PO4 at 5 minutes. The defect density calculated from observed etch-pits on surface was around 5 × 106/cm 2. This indicates that the fabricated GaN substrates can be used for applications in the field of optodevice, and high power electronics.
참고문헌 (10)
- H. Morkoc, "Large-band-gap SiC, III-V nitride, and II-VI ZnSe-based semiconductor device technologies", J. Appl. Phys., 76, pp.1363~ (1994)
- S. Yoshida, "Properties of AlxGa1 − xN films prepared by reactive molecular beam epitaxy", J. Appl. Phys., 53, pp.6844~ (1982)
- I. Grzegory, "III-V Nitridesthermodynamics and crystal growth at high N2 pressure", J. Phys. Chem. Solids, 56, pp.639~ (1995)
- O. Ambacher, "Thermal stability and desorption of Group III nitrides prepared by metal organic chemical vapor deposition", J. Vac. Sci. Techno., B14, pp.3532~ (1996)
- H.P. Maruska, "The preparation and property of vapor-deposited single-crystal-line GaN", Appl. Phys. Lett., 15, pp.327~ (1974)
- O. Madelung, "Data in Science and Technology" (1991), Springer
- T. Detchprom, "Relaxation process of the thermal strain in the GaN", a-Al2O3 heterostructure and determination of the intrinsic lattice constant of GaN free from the strain, 1992, pp.31, L1454~
- H.K. Jung, "Investigation of the Polarity in GaN Grown by HVPE", Korean J. Crystallography, 14(2), pp.93~ (2003)
- J.W. Lee, "Study on the growth characteristics of think gan on sapphire substrate using hydride vapor phase epitaxy", Korean Journal of Materials Research, 7(6) (1997)
- M. Herrera-Zaldivar, "Origin of yellow luminescence from reduced pressure grown bulk GaN crystals", Appl. Phys. A, 71, pp.55~ (2000)