Advertisement

Dislocation-Based Thermodynamic Models of V-Pits Formation and Strain Relaxation in InGaN/GaN Epilayers on Si Substrates

  • Khaled H. Khafagy
  • Tarek M. HatemEmail author
  • Salah M. Bedair
Conference paper
  • 114 Downloads
Part of the The Minerals, Metals & Materials Series book series (MMMS)

Abstract

The strain relaxation mechanism in III-N materials is occurred through the motion of dislocations that generated at III-N/Si interface as a result of large mismatch in lattice and thermal expansion coefficients. As a result of the large lattice mismatch between different layers, the upper layer gets strained and with thicker layers, the strain energy increases until a thickness limit called the critical material thickness. Most of such dislocations (threading dislocations) penetrate the top surface forming V-pits defects at the top surface that relax the material. These V-pits directly affect the device efficiency, performance, and reliability. Therefore, in this paper, a thermodynamics-based model will be used to study the V-pits formulation and growth in the III-N (especially, InGaN-based materials). In this model, three types of energies are used under a balanced system to model the V-pit formation and growth. These energies are the strain energy in the InGaN epilayer, the destruction energy as a result of dislocation to form the V-pit, and the strain energy of the V-pits facets that generated during the facet nucleation.

Keywords

Threading dislocations III-Nitride relaxation V-pits defects Thermodynamics modeling 

Notes

Acknowledgements

The support from the Young Investigators Research Grant (No. YIRG05) at the British University in Egypt and Research Grant from the Academy of Scientific Research and Technology (ASRT) are greatly appreciated.

References

  1. 1.
    Cheng J, Yang X, Sang L, Guo L, Zhang J, Wang J, He C, Zhang L, Wang M, Xu F, Tang N (2016) Growth of high quality and uniformity AlGaN/GaN heterostructures on Si substrates using a single AlGaN layer with low Al composition. Sci Rep 6:23020CrossRefGoogle Scholar
  2. 2.
    Kukushkin SA, Osipov AV, Bessolov VN, Medvedev BK, Nevolin VK, Tcarik KA (2008) Substrates for epitaxy of gallium nitride: new materials and techniques. Rev Adv Mater Sci 17(1/2):1–32Google Scholar
  3. 3.
    Khafagy KH, Hatem TM, Bedair SM (2018) Impact of embedded voids on thin-films with high thermal expansion coefficients mismatch. Appl Phys Lett 112(4):042109CrossRefGoogle Scholar
  4. 4.
    Khafagy KH, Hatem TM, Bedair SM (2018) Three-dimensional crystal-plasticity based model for intrinsic stresses in multi-junction photovoltaic. In: TMS annual meeting & exhibition. Springer, Cham, pp 453–461Google Scholar
  5. 5.
    Khafagy KH, Hatem TM, Bedair SM (2019) Modelling of III-Nitride epitaxial layers grown on silicon substrates with low dislocation-densities. MRS Adv 4(13):755–760CrossRefGoogle Scholar
  6. 6.
    Salah SI, Hatem TM, Khalil EE, Bedair SM (2019) Embedded void approach effects on intrinsic stresses in laterally grown GaN-on-Si substrate. Mater Sci Eng B 242:104–110Google Scholar
  7. 7.
    Hatem TM, Zikry MA (2011) A model for determining initial dislocation-densities associated with martensitic transformations. Mater Sci Eng 27(10):1570–1573Google Scholar
  8. 8.
    El-Etriby AE, Abdel-Meguid ME, Shalan KM, Hatem TM, Bahei-El-Din YA (2015) A multi-scale based model for composite materials with embedded PZT filaments for energy harvesting. In: TMS middle east—mediterranean materials congress on energy and infrastructure systems (MEMA 2015). Springer, Cham, pp 361–379Google Scholar
  9. 9.
    Hatem TM, Zikry MA (2010) Deformation and failure of single-packets in martensitic steels. Comput Mater Continua 17(2):127–147Google Scholar
  10. 10.
    Hatem TM (2009) Microstructural modeling of heterogeneous failure modes in martensitic steels. North Carolina State University, North CarolinaGoogle Scholar
  11. 11.
    Northrup JE, Romano LT, Neugebauer J (1999) Surface energetics, pit formation, and chemical ordering in InGaN alloys. Appl Phys Lett 74(16):2319–2321CrossRefGoogle Scholar
  12. 12.
    Northrup JE, Neugebauer J (1999) Indium-induced changes in GaN (0001) surface morphology. Phys Rev B 60(12):R8473CrossRefGoogle Scholar
  13. 13.
    Lobanova AV, Kolesnikova AL, Romanov AE, Karpov SY, Rudinsky ME, Yakovlev EV (2013) Mechanism of stress relaxation in (0001) InGaN/GaN via formation of V-shaped dislocation half-loops. Appl Phys Lett 103(15):152106CrossRefGoogle Scholar
  14. 14.
    Qi W, Zhang J, Mo C, Wang X, Wu X, Quan Z, Wang G, Pan S, Fang F, Liu J, Jiang F (2017) Effects of thickness ratio of InGaN to GaN in superlattice strain relief layer on the optoelectrical properties of InGaN-based green LEDs grown on Si substrates. J Appl Phys 122(8):084504CrossRefGoogle Scholar
  15. 15.
    Wu XH, Elsass CR, Abare A, Mack M, Keller S, Petroff PM, DenBaars SP, Speck JS, Rosner SJ (1998) Structural origin of V-defects and correlation with localized excitonic centers in InGaN/GaN multiple quantum wells. Appl Phys Lett 72(6):692–694CrossRefGoogle Scholar
  16. 16.
    Kim J, Cho YH, Ko DS, Li XS, Won JY, Lee E, Park SH, Kim JY, Kim S (2014) Influence of V-pits on the efficiency droop in InGaN/GaN quantum wells. Opt Express 22(103):A857–A866CrossRefGoogle Scholar
  17. 17.
    Frank FC (1951) LXXXIII. Crystal dislocations—elementary concepts and definitions. Lond Edinb Dublin Philos Mag J Sci 42(331):809–819Google Scholar
  18. 18.
    Van der Merwe JH, Ball CAB, Matthews JW (1975) Epitaxial growth. In: Matthews JW (ed) Part B. Academic, New York, p 493Google Scholar
  19. 19.
    Song TL (2005) Strain relaxation due to V-pit formation in In x Ga 1–x N/GaN epilayers grown on sapphire. J Appl Phys 98(8):084906CrossRefGoogle Scholar
  20. 20.
    Suhir E (1997) Predicted thermal mismatch stresses in a cylindrical bi-material assembly adhesively bonded at its ends. J Appl Mech 64(1):15–22CrossRefGoogle Scholar

Copyright information

© The Minerals, Metals & Materials Society 2020

Authors and Affiliations

  • Khaled H. Khafagy
    • 1
    • 2
  • Tarek M. Hatem
    • 2
    • 3
    Email author
  • Salah M. Bedair
    • 1
  1. 1.Department of Electrical and Computer EngineeringNorth Carolina State UniversityRaleighUSA
  2. 2.Faculty of Energy and Environmental Engineering, Centre for Simulation Innovation and Advanced ManufacturingThe British University in EgyptEl-Sherouk City, CairoEgypt
  3. 3.Faculty of Energy and Environmental EngineeringThe British University in EgyptEl-Sherouk City, CairoEgypt

Personalised recommendations