4.6 Epitaxial Technology of High Quality GaN on SiC Substrate
71
residual compressive stress in the GaN epitaxial layer is greater than the tensile stress
introduced by GaN during thermal cooling due to thermal mismatch, GaN will be
subjected to compressive stress at normal temperature and is less prone to cracking.
However, GaN grown on the surface of AlN is heteroepitaxial and tends to nucleate
where the surface of the AlN is undulating and defective. The GaN growth involves
both two-dimensional and three-dimensional mode [58, 62]. Therefore, the residual
compressive stress is largely released at the AlN/GaN interface. Since the residual
compressive stress is smaller than the tensile stress introduced by the difference in
thermal expansion coefficient, cracking occurs due to tensile stress enrichment in the
GaN epitaxial material. In summary, the stress in the SiC-based GaN epitaxial layer
ultimately depends on the superposition of the tensile stress caused by the difference
in compressive stress and thermal expansion coefficient caused by lattice mismatch.
References
1. www.bridgelux.com
2. www.cree.com
3. H. Amano, N. Sawaki, I. Akasaki et al., Metalorganic vapor-phase epitaxial-growth of a highquality GaN film using an AlN buffer layer. Appl. Phys. Lett. 48, 353 (1986)
4. H. Amano, M. Kito, K. Hiramatsu et al., p-type conduction in Mg-doped GaN treated with
low-energy electron-beam irradiation (LEEBI). Jpn. J. Appl. Phys. 28, L2112 (1989)
5. S. Nakamura, M. Senoh, T. Mukai, High-power GaN p-n-junction blue light emitting diodes.
Jpn. J. Appl. Phys. 30, L1708 (1991)
6. Z. Yu, M. Johnson, J. Brown et al., Study of the epitaxial lateral overgrowth process for GaN
on sapphire. J. Cryst. Growth 195, 333 (1998)
7. R. Davis, T. Gehrke, K. Linthicum et al., Conventional and pendeo-epitaxial growth of
GaN(0001) thin films on Si (111) substrates. J. Cryst. Growth 231, 335 (2001)
8. K. Hiramatsu, K. Nishiyama, M. Onishi et al., Fabrication and characterization of low defect
density GaN using facet controlled epitaxial lateral overgrowth. J. Cryst. Growth 221, 316
(2000)
9. http://lights.ofweek.com/2015
10. L. Wu, Proceedings of China SSL, Guangzhou, China (2014)
11. VEECO K465 MOCVD manual
12. M. Heuken, Latest MOCVD Production Technology for Solid-State Lighting (SSL, China,
2009)
13. www.veeco.com
14. K. Schmidegg, G. Neuwirt, D. Stifter et al., In situ optical analysis of low temperature MOCVD
GaN nucleation layer formation via multiple wavelength ellipsometry. J. Cryst. Growth 272,
106 (2004)
15. A. Springthorpe, T. Humphreys, A. Majeed et al., In situ growth rate measurements during
molecular beam epitaxy using an optical pyrometer. Appl. Phys. Lett. 55, 2138 (1989)
16. H. Grothe, F. Boebel, In situ control of Ga(Al)As MBE layers by pyrometric interferometry.
J. Cryst. Growth 127, 1010 (1993)
17. F.G. Bobel, H. Moller, A. Wowchak, et al., Pyrometric interferometry for real time molecular
beam epitaxy process monitoring. J. Vacuum Sci. Technol. B. 12, 1207 (1994)
18. H. Maruska, J. Tietjen, Preparation and properties of vapor-deposited single-crystalline GaN.
Appl. Phys. Lett. 15, 327 (1969)
19. V. Ban, Mass spectrometric studies of vapor-phase crystal growth 2 GaN. J. Electrochem. Soc.
119, 761 (1972)
71
residual compressive stress in the GaN epitaxial layer is greater than the tensile stress
introduced by GaN during thermal cooling due to thermal mismatch, GaN will be
subjected to compressive stress at normal temperature and is less prone to cracking.
However, GaN grown on the surface of AlN is heteroepitaxial and tends to nucleate
where the surface of the AlN is undulating and defective. The GaN growth involves
both two-dimensional and three-dimensional mode [58, 62]. Therefore, the residual
compressive stress is largely released at the AlN/GaN interface. Since the residual
compressive stress is smaller than the tensile stress introduced by the difference in
thermal expansion coefficient, cracking occurs due to tensile stress enrichment in the
GaN epitaxial material. In summary, the stress in the SiC-based GaN epitaxial layer
ultimately depends on the superposition of the tensile stress caused by the difference
in compressive stress and thermal expansion coefficient caused by lattice mismatch.
References
1. www.bridgelux.com
2. www.cree.com
3. H. Amano, N. Sawaki, I. Akasaki et al., Metalorganic vapor-phase epitaxial-growth of a highquality GaN film using an AlN buffer layer. Appl. Phys. Lett. 48, 353 (1986)
4. H. Amano, M. Kito, K. Hiramatsu et al., p-type conduction in Mg-doped GaN treated with
low-energy electron-beam irradiation (LEEBI). Jpn. J. Appl. Phys. 28, L2112 (1989)
5. S. Nakamura, M. Senoh, T. Mukai, High-power GaN p-n-junction blue light emitting diodes.
Jpn. J. Appl. Phys. 30, L1708 (1991)
6. Z. Yu, M. Johnson, J. Brown et al., Study of the epitaxial lateral overgrowth process for GaN
on sapphire. J. Cryst. Growth 195, 333 (1998)
7. R. Davis, T. Gehrke, K. Linthicum et al., Conventional and pendeo-epitaxial growth of
GaN(0001) thin films on Si (111) substrates. J. Cryst. Growth 231, 335 (2001)
8. K. Hiramatsu, K. Nishiyama, M. Onishi et al., Fabrication and characterization of low defect
density GaN using facet controlled epitaxial lateral overgrowth. J. Cryst. Growth 221, 316
(2000)
9. http://lights.ofweek.com/2015
10. L. Wu, Proceedings of China SSL, Guangzhou, China (2014)
11. VEECO K465 MOCVD manual
12. M. Heuken, Latest MOCVD Production Technology for Solid-State Lighting (SSL, China,
2009)
13. www.veeco.com
14. K. Schmidegg, G. Neuwirt, D. Stifter et al., In situ optical analysis of low temperature MOCVD
GaN nucleation layer formation via multiple wavelength ellipsometry. J. Cryst. Growth 272,
106 (2004)
15. A. Springthorpe, T. Humphreys, A. Majeed et al., In situ growth rate measurements during
molecular beam epitaxy using an optical pyrometer. Appl. Phys. Lett. 55, 2138 (1989)
16. H. Grothe, F. Boebel, In situ control of Ga(Al)As MBE layers by pyrometric interferometry.
J. Cryst. Growth 127, 1010 (1993)
17. F.G. Bobel, H. Moller, A. Wowchak, et al., Pyrometric interferometry for real time molecular
beam epitaxy process monitoring. J. Vacuum Sci. Technol. B. 12, 1207 (1994)
18. H. Maruska, J. Tietjen, Preparation and properties of vapor-deposited single-crystalline GaN.
Appl. Phys. Lett. 15, 327 (1969)
19. V. Ban, Mass spectrometric studies of vapor-phase crystal growth 2 GaN. J. Electrochem. Soc.
119, 761 (1972)