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Microstructural Characterization of GaN Grown on SiC

  • Sabyasachi Saha (a1), Deepak Kumar (a1), Chandan K. Sharma (a1), Vikash K. Singh (a2), Samartha Channagiri (a3) and Duggi V. Sridhara Rao (a1)...


GaN films have been grown on SiC substrates with an AlN nucleation layer by using a metal organic chemical vapor deposition technique. Micro-cracking of the GaN films has been observed in some of the grown samples. In order to investigate the micro-cracking and microstructure, the samples have been studied using various characterization techniques such as optical microscopy, atomic force microscopy, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy (TEM). The surface morphology of the AlN nucleation layer is related to the stress evolution in subsequent overgrown GaN epilayers. It is determined via TEM evidence that, if the AlN nucleation layer has a rough surface morphology, this leads to tensile stresses in the GaN films, which finally results in cracking. Raman spectroscopy results also suggest this, by showing the existence of considerable tensile residual stress in the AlN nucleation layer. Based on these various observations and results, conclusions or propositions relating to the microstructure are presented.


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*Author for correspondence: Sabyasachi Saha, E-mail:


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Al Balushi, ZY & Redwing, JM (2015). In situ stress measurements during direct MOCVD growth of GaN on SiC. J Mater Res 30, 29002909.
Amano, H, Baines, Y, Beam, E, Borga, M, Bouchet, T, Chalker, PR, Charles, M, Chen, KJ, Chowdhury, N, Chu, R, De Santi, C, De Souza, MM, Decoutere, S, Di Cioccio, L, Eckardt, B, Egawa, T, Fay, P, Freedsman, JJ, Guido, L, Häberlen, O, Haynes, G, Heckel, T, Hemakumara, D, Houston, P, Hu, J, Hua, M, Huang, Q, Huang, A, Jiang, S, Kawai, H, Kinzer, D, Kuball, M, Kumar, A, Lee, KB, Li, X, Marcon, D, März, M, McCarthy, R, Meneghesso, G, Meneghini, M, Morvan, E, Nakajima, A, Narayanan, EMS, Oliver, S, Palacios, T, Piedra, D, Plissonnier, M, Reddy, R, Sun, M, Thayne, I, Torres, A, Trivellin, N, Unni, V, Uren, MJ, Van Hove, M, Wallis, DJ, Wang, J, Xie, J, Yagi, S, Yang, S, Youtsey, C, Yu, R, Zanoni, E, Zeltner, S & Zhang, Y (2018). The 2018 GaN power electronics roadmap. J Phys D: Appl Phys 51, 163001.
Barghout, K & Chaudhuri, J (2004). Calculation of residual thermal stress in GaN epitaxial layers grown on technologically important substrates. J Mater Sci 39, 58175823.
Boeykens, S, Leys, MR, Germain, M, Belmans, R & Borghs, G (2004). Influence of AlGaN nucleation layers on structural and electrical properties of GaN on 4H-SiC. J Cryst Growth 272, 312317.
Chien, FR, Ning, XJ, Stemmer, S, Pirouz, P, Bremser, MD, Davis, RF, Chien, FR, Ning, XJ, Stemmer, S & Pirouz, P (1996). Growth defects in GaN films on 6H-SiC substrates. Appl Phys Lett 68, 26782680.
Chierchia, R, Böttcher, T, Heinke, H, Einfeldt, S, Figge, S & Hommel, D (2003). Microstructure of heteroepitaxial GaN revealed by x-ray diffraction. J Appl Phys 93, 89188925.
Cho, J, Park, JH, Kim, JK & Schubert, EF (2017). White light-emitting diodes: History, progress, and future. Laser Photonics Rev 11, 1600147.
Dadgar, A (2015). Sixteen years GaN on Si. Phys. Status Solidi B 252, 10631068.
Deng, G, Zhang, Y, Yu, Y, Huang, Z, Han, X & Chen, L (2018). Significantly reduced in-plane tensile stress of GaN films grown on SiC substrates by using graded AlGaN buffer and SiN x interlayer. Superlattice Microstruc 122, 7479.
Edwards, NV, Bremser, MD, Davis, RF, Batchelor, AD, Yoo, SD, Karan, CF & Aspnes, DE (1998). Trends in residual stress for GaN/AlN/6H-SiC heterostructures. Appl Phys Lett 73, 28082810.
Etzkorn, EV & Clarke, DR (2001). Cracking of GaN films. J Appl Phys 89, 10251034.
Faleev, N & Levin, I (2010). Strain and crystal defects in thin AlN/GaN structures on (0001) SiC. J Appl Phys 107, 113529.
Guojian, D, Liwei, G, Zhigang, X, Yao, C & Hong, C (2010). Characteristics of GaN grown on 6H-SiC with different AlN buffers. J Semicond 31, 15.
Harima, H (2002). Properties of GaN and related compounds studied by means of Raman scattering. J Phys Condens Matter 14, R967R993.
Horie, M, Ishihara, Y, Yamamoto, J, Kurimoto, M, Takano, T & Kawanishi, H (2002). Optical characteristic of the strain-controlled GaN epitaxial layer grown on 6H-SiC substrate by an adapting (GaN/AlN) multibuffer layer. Phys Status Solidi A 192, 151156.
Kakanakova-Georgieva, A, Persson, POÅ, Forsberg, U, Birch, J, Hultman, L & Janzén, E (2002). Epitaxial growth of AlN layers on SiC substrates in a hot-wall MOCVD system. Phys Status Solidi C 0, 205208.
Koleske, DD, Henry, RL, Twigg, ME, Culbertson, JC, Binari, SC, Wickenden, AE & Fatemi, M (2002). Influence of AlN nucleation layer temperature on GaN electronic properties grown on SiC. Appl Phys Lett 80, 43724374.
Kuball, M (2001). Raman spectroscopy of GaN, AlGaN and AlN for process and growth monitoring/control. Surf Interface Anal 31, 987999.
Kung, P & Razeghi, M (2000). III-Nitride wide bandgap semiconductors: a survey of the current status and future trends of the material and device technology. Opto-Electron Rev 8, 201239.
Li, Z & Bradt, RC (1986). Thermal expansion of the hexagonal (6H) polytype of silicon carbide. J Am Ceram Soc 69, 863866.
Liu, BT, Guo, SK, Ma, P, Wang, JX & Li, JM (2017). High-quality and strain-relaxation GaN epilayer grown on SiC substrates using AlN buffer and AlGaN interlayer. Chin Phys Lett 34, 048101.
Liu, L & Edgar, JH (2002). Substrates for gallium nitride epitaxy. Mater Sci Eng R Rep 37, 61128.
Morkoç, H (2009). Handbook of Nitride Semiconductors and Devices, Volume 3: GaN - based Optical and Electronic Devices. Weinheim: WILEY-VCHVerlag GmbH & Co. KGaA, ISBN: 978-3-527-40839-9.
Ozturk, MK, Arslan, E, Kars, I, Ozcelik, S & Ozbay, E (2013). Strain analysis of the GaN epitaxial layers grown on nitridated Si (111) substrate by metal organic chemical vapor deposition. Mater Sci Semicond Process 16, 8388.
Pernot, J, Bustarret, E, Rudziński, M, Hageman, PR & Larsen, PK (2007). Strain relaxation in GaN grown on vicinal 4H-SiC (0001) substrates. J Appl Phys 101, 033536.
Picard, YN, Liu, M, Lammatao, J, Kamaladasa, R & De Graef, M (2014). Theory of dynamical electron channeling contrast images of near-surface crystal defects. Ultramicroscopy 146, 7178.
Poblenz, C, Waltereit, P, Rajan, S, Mishra, UK, Speck, JS, Chin, P, Smorchkova, I & Heying, B (2005). Effect of AlN nucleation layer growth conditions on buffer leakage in AlGaN∕GaN high electron mobility transistors grown by molecular beam epitaxy (MBE). J Vac Sci Technol B Microelectron Nanometer Struct Process Meas Phenom 23, 15621567.
Ponce, FA, Krusor, BS, Major, JS, Plano, WE & Welch, DF (1995). Microstructure of GaN epitaxy on SiC using AlN buffer layers. Appl Phys Lett 67, 410412.
Qu, S, Li, S, Peng, Y, Zhu, X, Hu, X, Wang, C, Chen, X, Gao, Y & Xu, X (2010). Influence of the growth temperature of AlN buffer on the quality and stress of GaN films grown on 6H-SiC substrate by MOVPE. J Alloys Compd 502, 417422.
Quay, R (2008). Gallium Nitride Electronics, vol. 96. Berlin, Heidelberg: Springer-Verlag.
Rao, DVS, Muraleedharan, K & Humphreys, CJ (2010). TEM specimen preparation techniques. In Microscopy: Science, Technology, Applications and Education, Méndez-Vilas, A & Díaz, J (Eds.), pp. 12321244. FORMATEX.
Reeber, RR & Wang, K (2000). Lattice parameters and thermal expansion of GaN. J Mater Res 15, 4044.
Röder, C, Lipski, F, Habel, F, Leibiger, G, Abendroth, M, Himcinschi, C & Kortus, J (2013). Raman spectroscopic characterization of epitaxially grown GaN on sapphire. J Phys D: Appl Phys 46, 285302.
Ruterana, P, Albrecht, M & Neugebauer, J (2003). Nitride Semiconductors: Handbook on Materials and Devices. Weinheim: WILEY-VCH Verlag GmbH & Co. KGaA.
Ruvimov, S, Liliental-Weber, Z, Dieker, C, Washburn, J, Koike, M, Amano, H & Akasaki, I (1997). TEM/HREM analysis of defects in GaN epitaxial layers grown by MOVPE on SiC and sapphire. In Materials Research Society Symposium Proceedings, vol. 468, pp. 287–292.
Song, S, Liu, Y, Liang, H, Yang, D, Zhang, K, Xia, X, Shen, R & Du, G (2013). Improvement of quality and strain relaxation of GaN epilayer grown on SiC substrate by in situ SiNx interlayer. J Mater Sci: Mater Electron 24, 29232927.
Waltereit, P, Brandt, O, Trampert, A, Ramsteiner, M, Reiche, M & Qi, M (1999). Influence of AlN nucleation layers on growth mode and strain relief of GaN grown on 6H-SiC(0001). Appl Phys Lett 74, 36603662.
Yaddanapudi, K, Saha, S, Raghavan, S, Muraleedharan, K & Banerjee, D (2018). The nitridation of sapphire as a precursor to GaN growth: Structure and chemistry. Cryst Growth Des 18, 49784986.
Zhao, DG, Xu, SJ, Xie, MH, Tong, SY & Yang, H (2003). Stress and its effect on optical properties of GaN epilayers grown on Si(111), 6H-SiC(0001), and c-plane sapphire. Appl Phys Lett 83, 677679.


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Microstructural Characterization of GaN Grown on SiC

  • Sabyasachi Saha (a1), Deepak Kumar (a1), Chandan K. Sharma (a1), Vikash K. Singh (a2), Samartha Channagiri (a3) and Duggi V. Sridhara Rao (a1)...


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