Highly Reflective Low Resistance Pt/Ag/Ni/Au Based Ohmic Contacts on p-GaN

  • A. ChauhanEmail author
  • Kuldip Singh
  • Manish Mathew
  • Rajender Singh Kundu
  • Rajesh Punia
Conference paper
Part of the Springer Proceedings in Physics book series (SPPHY, volume 215)


A metallization scheme of Pt/Ag/Ni/Au (0.6/120/20/40 nm) metal layers with high reflectance and good surface morphology has been developed for obtaining low resistance ohmic contact on p-GaN. These metal layers were deposited by electron beam evaporation system on p-GaN. The metal contacts were annealed in different ambient conditions (N2, air and N2 + O2). The as-deposited contacts exhibit nonlinear current-voltage behaviour with reflectivity of ~95% at 470 nm wavelength. The air annealed Pt/Ag/Ni/Au contacts at 500 °C exhibit linear current-voltage behaviour with low specific contact resistance of 2.4 × 10−2 Ω-cm2. The reflectivity of air annealed contact at 500 °C was decreased to ~88.4% at ~470 nm compared to as-deposited contacts (~95%).


p-GaN Highly reflective ohmic contacts Rapid thermal annealing Surface morphology 



This work was supported by council of scientific and industrial research (CSIR) under network programme (NWP-55).


  1. 1.
    M. Koike, N. Shibata, H. Kato, Y. Takahashi. Development of high efficiency GaN-based multiquantum-well light-emitting diodes and their applications. IEEE J. Sel. Top. Quantum Electron. 8(2), 271–277 (2002)ADSCrossRefGoogle Scholar
  2. 2.
    S.P. DenBaars, D. Feezell, K. Kelchner, S. Pimputkar, C.-C. Pan, C.-C. Yen, S. Tanaka, Y. Zhao, N. Pfaff, R. Farrell, M. Iza, S. Keller, U. Mishra, J.S. Speck, S. Nakamura, Development of gallium-nitride-based light-emitting diodes (LEDs) and laser diodes for energy-efficient lighting and displays. Acta Mater. 61, 945–951 (2013)CrossRefGoogle Scholar
  3. 3.
    H.W. Jang, J.H. Son, J.-L. Lee, Highly reflective low resistance Ag-based ohmic contacts on p-type GaN using Mg overlayer. Appl. Phys. Lett. 90, 012106-1–012106-3 (2007)ADSCrossRefGoogle Scholar
  4. 4.
    H.W. Jang, J.H. Son, J.-L. Lee, Formation of high-quality Ag-based ohmic contacts to p- type GaN. J. Electrochem. Soc. 155(8), H563–H568 (2008)CrossRefGoogle Scholar
  5. 5.
    F. Jiang, L.-E. Cai, J.-Y. Zhang, B.-P. Zhang, Formation of high reflective Ni/Ag/Ti/Au contact on p-GaN. Phys. E 42, 2420–2423 (2010)CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  • A. Chauhan
    • 1
    Email author
  • Kuldip Singh
    • 1
  • Manish Mathew
    • 1
  • Rajender Singh Kundu
    • 2
  • Rajesh Punia
    • 2
  1. 1.Optoelectronics Devices GroupCSIR-Central Electronics Engineering Research InstitutePilaniIndia
  2. 2.Department of Applied PhysicsGuru Jambheshwar University of Science and TechnologyHisarIndia

Personalised recommendations