AlN 단결정의 품질평가를 위한 molten KOH/NaOH eutectic alloy의 화학적 습식에칭
Wet chemical etching of molten KOH/NaOH eutectic alloy to evaluate AlN single crystal
1
조회
0
다운로드
0
인용
0
참고문헌
키워드
초록
본 연구에서는 상용화되는 AlN 웨이퍼(wafer)를 이용하여 molten KOH/NaOH 화학적 습식 에칭(Wet ChemicalEtching)에 따른 표면변화 특성 및 최적의 에칭 조건을 조사하였다. AlN 웨이퍼를 350oC에서 5분간 에칭 시 Al-face, N-face는 서로 다른 관찰되었다. 특히, Al-face는 에치핏의 형상을 파악하여 결함특성을 관찰하였고, 이로부터 결함 밀도를 계산하여 2 × 106/cm2~1010/cm2의 결과를 얻었다. N-face의 경우 육각 뿔(hexagonal pyramids) 형태의 격자결함이 형성되었다. 또한AlN 웨이퍼의 성장 시 배향을 관찰하기 위해 XRD(X-Ray Diffraction, Rigaku, JAPAN)를 이용하여 분석한 결과 육방정AlN의 C축 방향에 해당되는 (0002) 및 (0004) 면으로 배향된 상태임을 알 수 있었고, DC-XRD(Double Crystal X-rayDiffraction, bruker, Germany)를 이용하여 rocking curve의 위치에 따라 곡률 반경을 측정했을 때 1.6~17 m의 곡률을 가지고있는 것으로 나타났다. †Corresponding
Abstract
We investigated the optimal etching conditions and properties of the surface change due to molten KOH/NaOHchemical wet etching using an AlN wafer which has been put to practical use in the present study. Results were observedusing a scanning electron microscope after 5 minutes etching at 350oC, was found to have a surface form of the respectiveother Al-face, the N-face. In particular, etch-pit in the form of a hexagon, which is observed in the Al-face appeared, Itwas calculated at 2 × 106/cm2~1010/cm2dislocation density. In the case of N-face, lattice defects in the form of the hexagonalpyramids is formed. It was discovered that in order to observe the orientation of the wafer, which corresponds to the Caxisdirection of the resulting hexagonal AlN which was analyzed using XRD (0002) and is a state of being oriented inthe (0004) plane. The Radius of curvature of AlN wafer was 1.6~17 m measured by DC-XRD rocking curve position.
참고문헌 (10)
- M. Miyanaga, "Evaluation of AlN singlecrystalgrown by sublimation method", J. CrystalGrowth, 300, pp.45~ (2007)
- Yu. N. Makarov, "Experimentaland theoretical analysis of sublimation growth ofAlN bulk crystals", J. Crystal Growth, 310, pp.881~ (2008)
- 오동근, "HVPE법으로 성장시킨 GaN 단결정의 wet etching에 의한 표면 변화", 한국결정성장학회지, 22(6), pp.261~264 (2012), 한국결정성장학회
- D. Zhuang, "Defect-selective etching of bulk AlN single crystalsin molten KOH", NaOH eutectic alloy, 2004, pp.262, 89~
- M. Bickermann, "Wet KOH etchingof freestanding AlN single crystals", J. Crystal Growth, 300, pp.299~ (2007)
- A.K. Georgieva, "Sublimation epitaxy of AlN onSiC: growth morphology and structural features", J. Crystal Growth, 273, pp.161~ (2004)
- I. Nagai, "AlN bulk single crystalgrowth on 6H-SiC substrates by sublimation method", J. Crystal Growth, 312, pp.2699~ (2010)
- R.R. Sumathi, "Structural and surface topography analysis of AlN singlecrystals grown on 6H-SiC substrates", J. CrystalGrowth, 360, pp.193~ (2012)
- R. Dwilinski, "Excellent crystallinity oftruly bulk ammonothermal GaN", J. Crystal Growth, 310, pp.3911~ (2008)
- D. Peng, "Effect of surface treatmentfor sapphire substrate on gallium nitride films", J. Alloys Compd, 476, pp.629~ (2009)