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Journal of Electrical Engineering

The Journal of Slovak University of Technology

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Improving the ohmic properties of contacts to P–GaN by adding p–type dopants into the metallization layer

1 / Peter Vogrinčič1 / Andrej Vincze2 / Juraj Breza1 / Ivan Hotový1

1Slovak University of Technology, Faculty of Electrical Engineering and Information Technology, Ilkoviˇcova 3, 812 19 Bratislava

2International Laser Centre, Ilkoviˇcova 3, 812 19 Bratislava, Slovakia

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Citation Information: Journal of Electrical Engineering. Volume 63, Issue 6, Pages 397–401, ISSN (Online) , ISSN (Print) 1335-3632, DOI: 10.2478/v10187-012-0059-x, December 2012

Publication History

Published Online:
2012-12-29

The work investigates an increase of the density of free charge carriers in the sub-surface region of p-GaN by adding p-type dopants into the Ni-O layer of an Au/Ni-O metallization structure. We have examined electrical properties and concentration depth profiles of contact structures Au/Ni-Mg-O/p-GaN and Au/Ni-Zn-O/p-GaN, thus with magnesium and zinc as p-type dopants. The metallization layers were deposited on p-GaN by DC reactive magnetron sputtering in an atmosphere with a low concentration of oxygen (0.2 at%). The contacts were annealed in N2 . We have found that the structures containing magnesium or zinc exhibit lower values of contact resistivity in comparison with otherwise identical contacts without Mg or Zn dopants. In our opinion, the lower values of contact resistivity of the structures containing of Mg or Zn are caused by an increased density of holes in the sub-surface region of p-GaN due to diffusion of Mg or Zn from the deposited doped contact layers.

Keywords: p-GaN; ohmic contact; contact resistivity; Au/Ni-Mg(Zn)-O/p-GaN contact structure; annealing; Auger electron spectra; secondary ion mass spectra

  • [1] MURAKAMI,M. et al : Ohmic contacts for compound semiconductors, Crit. Rev. in Sol. State and Mat. Sci. 23 No. 1 (1998).

  • [2] CHEN, L. C. et al : GaN-based light-emitting diodes with Ni/AuBe transparent conductive layers, Solid State Electron. 47 (2003), 1843.

  • [3] YOUN, D. H. et al : Ohmic contacts to p-type GaN, Jpn. J. Appl. Phys. Part 1, 37 (1998)), 1768.

  • [4] SONG, J. O. et al : Formation of low resistance and transparent ohmic contacts to p-type GaN using Ni-Mg solid solution, Appl. Phys. Lett. 83 (2004), 3513.

  • [5] SONG, J. O. et al : Low-resistance Ni-Zn solid solution /Pd ohmic contacts to p-type GaN, Semicond. Sci. Technol. 19 (2004), 669.

  • [6] HO, J. K. et al : Low-resistance ohmic contacts to p-type GaN, Appl. Phys. Lett. 74 (1999), 1275.

  • [7] SONG, J. O. et al : Low-resistance and transparent ohmic contacts to p-type GaN using Ni-Zn solid solution /Au scheme, Appl. Phys. Lett. 84 (2004), 4663.

  • [8] HO, J. K. et al : Low-resistance ohmic contacts to p-type GaN achieved by the oxidation of Ni/Au films, J. Appl. Phys. 86 (1999), 4491.

  • [9] KOIDE, Y. et al : Effects of annealing in an oxygen ambient on electrical properties of ohmic contacts to p-type GaN, J. Electron. Mater. 28 (1999), 341.

  • [10] LIDAY, J. et al : ., Auger electron spectroscopy of Au/NiOx contacts on p-GaN annealed in N2 and O2 + N2 ambients, Appl. Surf. Sci. 253 (2007), 3174.

  • [11] LIDAY, J. et al : Ohmic contacts to p-GaN using Au/Ni-Mg-O metallization, J. Electrical Engn. 61 (2010), 374.

Bionotes

Jozef Liday

Jozef Liday (Assoc Prof, PhD) graduated in solid state physics in 1968 and received his PhD in electronics and vacuum technology, both from STU, in 1985. His teaching and research activities include materials analysis, thin films and surface science.

Peter Vogrinčič

Peter Vogrinˇciˇc (Ing), graduated in radio-electronics from the Slovak University of Technology in 1992. He is engaged in research, particularly in Auger analysis and depth profiling.

Andrej Vincze

Andrej Vincze (PhD), graduated in Microelectronics from the Slovak University of Technology in Bratislava in 1999 and received his PhD degree from the STU at 2006. His work is focused to semiconductor and material analysis using SIMS at the International Laser Centre in Bratislava

Juraj Breza

Juraj Breza (Prof, PhD) born in Bratislava in 1951, graduated in solid state physics in 1974 and received his PhD in electronics and vacuum technology, both from STU, in 1982. Professor in electronics. His research and teaching activities include materials analysis, thin films, surface science and superconductor electronics

Ivan Hotový

Ivan Hotov´y (Prof, DrSc) received his MSc in Electronics from the Slovak University of Technology in Bratislava in 1982 and his PhD in Electronics from the Slovak University of Technology in 1994. He is a scientific worker and lecturer at Department of Microelectronics, FEIT STU. His current research interests include the development of gas sensors, magnetron sputtering of metal oxide films and plasma etching of compound semiconductors.

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