JIA-EN SUI, JIAN-WEI BEN, HANG ZANG, et al. Mechanism of a-AlN Surface Morphology Evolution by High Temperature Annealing. [J]. Chinese journal of luminescence, 2021, 42(6): 810-817.
DOI:
JIA-EN SUI, JIAN-WEI BEN, HANG ZANG, et al. Mechanism of a-AlN Surface Morphology Evolution by High Temperature Annealing. [J]. Chinese journal of luminescence, 2021, 42(6): 810-817. DOI: 10.37188/CJL.20210111.
Mechanism of a-AlN Surface Morphology Evolution by High Temperature Annealing增强出版
-AlN is the fundamental method to eliminate quantum-confined Stark effect
and further improve the efficiency of AlGaN-based devices such as light-emitting diodes. However
it is hard to obtain high quality nonpolar
a
-AlN on heterogeneous substrates because the large and inhomogeneous mismatch between the heterogeneous substrate and the epitaxial layer. High temperature annealing is an effective and repeatable method to improve the quality of AlN templates. However
the physical mechanism is still not clear on how the high temperature annealing method effects the surface morphology of non-polar AlN
which affects the quality improvement of
a
-AlN. In this work
the surface evolution of the
a
-AlN with high temperature annealing has been investigated and the mechanism of how the thermal annealing effects on the surface evolution has been explored both by experiment and first-principles calculations. It is found that the Al/N atoms tend to decompose along
a
-/
m
-plane AlN and reabsorb along
c
-plane AlN
which result in the phenomenon that the area of ordered stripes along
c
-axis increases with higher annealing temperature or longer annealing time. The research will provide deeper understanding on the mechanism of the HTA effect on
a
-AlN
which will be benefit to the fabrication of
a
-AlN related devices.
关键词
a-AlN高温热处理表面形貌演变结合能
Keywords
a-AlNhigh temperature annealingsurface morphology evolutionbinding energy
references
LI D B, JIANG K, SUN X J, et al. AlGaN photonics: recent advances in materials and ultraviolet devices [J].Adv. Opt. Photonics, 2018, 10(1):43-110.
BEN J W, SUN X J, JIA Y P, et al. Defect evolution in AlN templates on PVD-AlN/sapphire substrates by thermal annealing [J].CrystEngComm, 2018, 20(32):4623-4629.
JIANG K, SUN X J, BEN J W, et al. The defect evolution in homoepitaxial AlN layers grown by high-temperature metal-organic chemical vapor deposition [J].CrystEngComm, 2018, 20(19):2720-2728.
BRYAN I, BRYAN Z, BOBEA M, et al. Homoepitaxial AlN thin films deposited on m-plane (1<math id="M1"><mover accent="true"><mn>1</mn><mo>¯</mo></mover></math>00) AlN substrates by metalorganic chemical vapor deposition [J].J. Appl. Phys., 2014, 116(13):133517.
KIM H S, LIN J Y, JIANG H X, et al. Piezoelectric effects on the optical properties of GaN/AlxGa1-xN multiple quantum wells [J].Appl. Phys. Lett., 1998, 73(23):3426-3428.
MASUI H, NAKAMURA S, DENBAARS S P, et al. Nonpolar and semipolar Ⅲ-nitride light-emitting diodes:achievements and challenges [J].IEEE Trans. Electron Devices, 2010, 57(1):88-100.
ZHANG Z H, LIU W, JU Z G, et al. Self-screening of the quantum confined Stark effect by the polarization induced bulk charges in the quantum barriers [J].Appl. Phys. Lett., 2014, 104(24):243501-1-5.
CHANG J Y, CHANG H T, SHIH Y H, et al. Efficient carrier confinement in deep-ultraviolet light-emitting diodes with composition-graded configuration [J].IEEE Trans. Electron Devices, 2017, 64(12):4980-4984.
AKASAKA T, KOBAYASHI Y, MAKIMOTO T. Growth of nonpolar AlN(11<math id="M2"><mover accent="true"><mn>2</mn><mo>¯</mo></mover></math>0) and (1<math id="M3"><mover accent="true"><mn>1</mn><mo>¯</mo></mover></math>00) films on SiC substrates by flow-rate modulation epitaxy [J].Appl. Phys. Lett., 2007, 90(12):121919.
VENNÉGUÈS P, BOUGRIOUA Z. Epitaxial orientation of Ⅲ-nitrides grown on R-plane sapphire by metal-organic-vapor-phase epitaxy [J].Appl. Phys. Lett., 2006, 89(11):111915-1-3.
FAN R, HAO Z B, CHEN Z, et al. High quality AlN with a thin interlayer grown on a sapphire substrate by plasma-assisted molecular beam epitaxy [J].Chin. Phys. Lett., 2010, 27(6):068101-1-4.
SHIBATA T, ASAI K, NAKAMURA Y, et al. AlN epitaxial growth on off-angle R-plane sapphire substrates by MOCVD [J].J. Cryst. Growth, 2001, 229(1-4):63-68.
MIYAGAWA R, MIYAKE H, HIRAMATSU K. a-plane AlN and AlGaN growth on r-plane sapphire by MOVPE [J].Phys. Status Solidi C, 2010, 7(7-8):2107-2110.
OKADA N, KATO N, SATO S, et al. Growth of high-quality and crack free AlN layers on sapphire substrate by multi-growth mode modification [J].J. Cryst. Growth, 2007, 298:349-353.
OKADA N, KATO N, SATO S, et al. Epitaxial lateral overgrowth of a-AlN layer on patterned a-AlN template by HT-MOVPE [J].J. Cryst. Growth, 2007, 300(1):141-144.
BEN J W. Defect Control and Physical Properties of AlN [D].Changchun:Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 2019. (in Chinese)
MATSUNAMI N, KAKIUCHIDA H, SATAKA M, et al. XRD characterization of AlN thin films prepared by reactive RF-sputter deposition [J].Adv. Mater. Phys. Chem., 2013, 3(1):101-107.
FOXON C T, NOVIKOV S V, STANTON N M, et al. Free-standing zinc-blende (cubic) GaN substrates grown by a molecular beam epitaxy process [J]Phys. Status Solidi B, 2008, 245(5):890-892.
MOGAMI Y, OSAWA A, OZAKI K, et al. Enhanced strain relaxation in AlGaN layers grown on sputter-based AlN templates [J].Phys. Status Solidi B, 2020, 257(4):1900590.
NAGAMATSU K, LIU X T, UESUGI K, et al. Improved emission intensity of UVC-LEDs from using strain relaxation layer on sputter-annealed AlN [J].Jpn. J. Appl. Phys., 2019, 58(SC):SCCC07-1-4.
LIN C H, YAMASHITA Y, MIYAKE H, et al. Fabrication of high-crystallinity a-plane AlN films grown on r-plane sapphire substrates by modulating buffer-layer growth temperature and thermal annealing conditions [J].J. Cryst. Growth, 2017, 468:845-850.
LIN C H, TAMAKI S, YAMASHITA Y, et al. Effects of AlN buffer layer thickness on the crystallinity and surface morphology of 10-μm-thick a-plane AlN films grown on r-plane sapphire substrates [J].Appl. Phys. Express, 2016, 9(8):081001-1-4.
JINNO D, OTSUKI S, SUGIMORI S, et al. Characterization and optimization of sputtered AlN buffer layer on r-plane sapphire substrate to improve the crystalline quality of nonpolar a-plane GaN [J].J. Cryst. Growth, 2017, 480:90-95.
AMMANN M W, BRODHOLT J P, DOBSON D P. DFT study of migration enthalpies in MgSiO3 perovskite [J].Phys. Chem. Miner., 2009, 36(3):151-158.
PERDEW J P, BURKE K, ERNZERHOF M. Generalized gradient approximation made simple [J].Phys. Rev. Lett., 1996, 77(18):3865-3868.
KRESSE G, JOUBERT D. From ultrasoft pseudopotentials to the projector augmented-wave method [J].Phys. Rev. B, 1999, 59(3):1758-1775.
JINDAL V, SHAHEDIPOUR-SANDVIK F. Density functional theoretical study of surface structure and adatom kinetics for wurtzite AlN [J].J. Appl. Phys., 2009, 105(8):084902-1-6.
YU Y P, LIN S H, HUANG C, et al. Effect of thickness homogeneity on optical transmittance spectra of a-Si∶H films [J].J. Shantou Univ. (Nat. Sci.), 2004, 19(1):50-54. (in Chinese)