AlN overgrowth of nano-pillar-patterned sapphire with different offcut angle by metalorganic vapor phase epitaxy

S. Walde, S. Hagedorn, P.-M. Coulon, A. Mogilatenko, C. Netzel, J. Weinrich, N. Susilo, E. Ziffer, L. Matiwe, C. Hartmann, G. Kusch, A. Alasmari, G. Naresh-Kumar, C. Trager-Cowan, T. Wernicke, T. Straubinger, M. Bickermann, R. W. Martin, P. A. Shields, M. KneisslM. Weyers

Research output: Contribution to journalArticle

Abstract

We present overgrowth of nano-patterned sapphire with different offcut angles by metalorganic vapor phase epitaxy. Hexagonal arrays of nano-pillars were prepared via Displacement Talbot Lithography and dry-etching. 6.6 µm crack-free and fully coalesced AlN was grown on such substrates. Extended defect analysis comparing X-ray diffraction, electron channeling contrast imaging and selective defect etching revealed a threading dislocation density of about 109 cm-2. However, for c-plane sapphire offcut of 0.2° towards m direction the AlN surface shows step bunches with a height of 10 nm. The detrimental impact of these step bunches on subsequently grown AlGaN multi-quantum-wells is investigated by cathodoluminescence and transmission electron microscopy. By reducing the sapphire offcut to 0.1° the formation of step bunches is successfully suppressed. On top of such a sample an AlGaN-based UVC LED heterostructure is realized emitting at 265 nm and showing an emission power of 0.81 mW at 20 mA (corresponds to an external quantum efficiency of 0.86 %).
Original languageEnglish
Article number125343
Number of pages6
JournalJournal of Crystal Growth
Volume531
Early online date13 Nov 2019
DOIs
Publication statusPublished - 1 Feb 2020

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Metallorganic vapor phase epitaxy
Aluminum Oxide
Sapphire
vapor phase epitaxy
sapphire
etching
Defects
Dry etching
Cathodoluminescence
defects
cathodoluminescence
Quantum efficiency
Lithography
X ray diffraction analysis
Semiconductor quantum wells
Light emitting diodes
Heterojunctions
quantum efficiency
Etching
light emitting diodes

Keywords

  • metal organic vapor phase epitaxy
  • nitrides
  • sapphire
  • light emitting diodes

Cite this

Walde, S., Hagedorn, S., Coulon, P-M., Mogilatenko, A., Netzel, C., Weinrich, J., ... Weyers, M. (2020). AlN overgrowth of nano-pillar-patterned sapphire with different offcut angle by metalorganic vapor phase epitaxy. Journal of Crystal Growth, 531, [125343]. https://doi.org/10.1016/j.jcrysgro.2019.125343
Walde, S. ; Hagedorn, S. ; Coulon, P.-M. ; Mogilatenko, A. ; Netzel, C. ; Weinrich, J. ; Susilo, N. ; Ziffer, E. ; Matiwe, L. ; Hartmann, C. ; Kusch, G. ; Alasmari, A. ; Naresh-Kumar, G. ; Trager-Cowan, C. ; Wernicke, T. ; Straubinger, T. ; Bickermann, M. ; Martin, R. W. ; Shields, P. A. ; Kneissl, M. ; Weyers, M. / AlN overgrowth of nano-pillar-patterned sapphire with different offcut angle by metalorganic vapor phase epitaxy. In: Journal of Crystal Growth. 2020 ; Vol. 531.
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abstract = "We present overgrowth of nano-patterned sapphire with different offcut angles by metalorganic vapor phase epitaxy. Hexagonal arrays of nano-pillars were prepared via Displacement Talbot Lithography and dry-etching. 6.6 µm crack-free and fully coalesced AlN was grown on such substrates. Extended defect analysis comparing X-ray diffraction, electron channeling contrast imaging and selective defect etching revealed a threading dislocation density of about 109 cm-2. However, for c-plane sapphire offcut of 0.2° towards m direction the AlN surface shows step bunches with a height of 10 nm. The detrimental impact of these step bunches on subsequently grown AlGaN multi-quantum-wells is investigated by cathodoluminescence and transmission electron microscopy. By reducing the sapphire offcut to 0.1° the formation of step bunches is successfully suppressed. On top of such a sample an AlGaN-based UVC LED heterostructure is realized emitting at 265 nm and showing an emission power of 0.81 mW at 20 mA (corresponds to an external quantum efficiency of 0.86 {\%}).",
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author = "S. Walde and S. Hagedorn and P.-M. Coulon and A. Mogilatenko and C. Netzel and J. Weinrich and N. Susilo and E. Ziffer and L. Matiwe and C. Hartmann and G. Kusch and A. Alasmari and G. Naresh-Kumar and C. Trager-Cowan and T. Wernicke and T. Straubinger and M. Bickermann and Martin, {R. W.} and Shields, {P. A.} and M. Kneissl and M. Weyers",
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Walde, S, Hagedorn, S, Coulon, P-M, Mogilatenko, A, Netzel, C, Weinrich, J, Susilo, N, Ziffer, E, Matiwe, L, Hartmann, C, Kusch, G, Alasmari, A, Naresh-Kumar, G, Trager-Cowan, C, Wernicke, T, Straubinger, T, Bickermann, M, Martin, RW, Shields, PA, Kneissl, M & Weyers, M 2020, 'AlN overgrowth of nano-pillar-patterned sapphire with different offcut angle by metalorganic vapor phase epitaxy', Journal of Crystal Growth, vol. 531, 125343. https://doi.org/10.1016/j.jcrysgro.2019.125343

AlN overgrowth of nano-pillar-patterned sapphire with different offcut angle by metalorganic vapor phase epitaxy. / Walde, S.; Hagedorn, S.; Coulon, P.-M.; Mogilatenko, A.; Netzel, C.; Weinrich, J.; Susilo, N.; Ziffer, E.; Matiwe, L.; Hartmann, C.; Kusch, G.; Alasmari, A.; Naresh-Kumar, G.; Trager-Cowan, C.; Wernicke, T.; Straubinger, T.; Bickermann, M.; Martin, R. W.; Shields, P. A.; Kneissl, M.; Weyers, M.

In: Journal of Crystal Growth, Vol. 531, 125343, 01.02.2020.

Research output: Contribution to journalArticle

TY - JOUR

T1 - AlN overgrowth of nano-pillar-patterned sapphire with different offcut angle by metalorganic vapor phase epitaxy

AU - Walde, S.

AU - Hagedorn, S.

AU - Coulon, P.-M.

AU - Mogilatenko, A.

AU - Netzel, C.

AU - Weinrich, J.

AU - Susilo, N.

AU - Ziffer, E.

AU - Matiwe, L.

AU - Hartmann, C.

AU - Kusch, G.

AU - Alasmari, A.

AU - Naresh-Kumar, G.

AU - Trager-Cowan, C.

AU - Wernicke, T.

AU - Straubinger, T.

AU - Bickermann, M.

AU - Martin, R. W.

AU - Shields, P. A.

AU - Kneissl, M.

AU - Weyers, M.

PY - 2020/2/1

Y1 - 2020/2/1

N2 - We present overgrowth of nano-patterned sapphire with different offcut angles by metalorganic vapor phase epitaxy. Hexagonal arrays of nano-pillars were prepared via Displacement Talbot Lithography and dry-etching. 6.6 µm crack-free and fully coalesced AlN was grown on such substrates. Extended defect analysis comparing X-ray diffraction, electron channeling contrast imaging and selective defect etching revealed a threading dislocation density of about 109 cm-2. However, for c-plane sapphire offcut of 0.2° towards m direction the AlN surface shows step bunches with a height of 10 nm. The detrimental impact of these step bunches on subsequently grown AlGaN multi-quantum-wells is investigated by cathodoluminescence and transmission electron microscopy. By reducing the sapphire offcut to 0.1° the formation of step bunches is successfully suppressed. On top of such a sample an AlGaN-based UVC LED heterostructure is realized emitting at 265 nm and showing an emission power of 0.81 mW at 20 mA (corresponds to an external quantum efficiency of 0.86 %).

AB - We present overgrowth of nano-patterned sapphire with different offcut angles by metalorganic vapor phase epitaxy. Hexagonal arrays of nano-pillars were prepared via Displacement Talbot Lithography and dry-etching. 6.6 µm crack-free and fully coalesced AlN was grown on such substrates. Extended defect analysis comparing X-ray diffraction, electron channeling contrast imaging and selective defect etching revealed a threading dislocation density of about 109 cm-2. However, for c-plane sapphire offcut of 0.2° towards m direction the AlN surface shows step bunches with a height of 10 nm. The detrimental impact of these step bunches on subsequently grown AlGaN multi-quantum-wells is investigated by cathodoluminescence and transmission electron microscopy. By reducing the sapphire offcut to 0.1° the formation of step bunches is successfully suppressed. On top of such a sample an AlGaN-based UVC LED heterostructure is realized emitting at 265 nm and showing an emission power of 0.81 mW at 20 mA (corresponds to an external quantum efficiency of 0.86 %).

KW - metal organic vapor phase epitaxy

KW - nitrides

KW - sapphire

KW - light emitting diodes

U2 - 10.1016/j.jcrysgro.2019.125343

DO - 10.1016/j.jcrysgro.2019.125343

M3 - Article

VL - 531

JO - Journal of Crystal Growth

JF - Journal of Crystal Growth

SN - 0022-0248

M1 - 125343

ER -