Abstract

In search of a better transparent contact to p-GaN, we analyze various metal/indium-tin-oxide (ITO) (Ag/ITO, AgCu/ITO, Ni/ITO, and NiZn/ITO) contact schemes and compare to Ni/Au, NiZn/Ag, and ITO. The metal layer boosts conductivity while the ITO thickness can be adjusted to constructive transmission interference on GaN that exceeds extraction from bare GaN. We find a best compromise for an Ag/ITO (3nm/67nm) ohmic contact with a relative transmittance of 97% of the bare GaN near 530 nm and a specific contact resistance of 0.03Ω·cm2. The contact proves suitable for green light-emitting diodes in epi-up geometry.

© 2012 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. I. Akasaki and H. Amano, “Crystal growth and conductivity control of group III nitride semiconductors and their application to short wavelength light emitters,” Jpn. J. Appl. Phys. 36, 5393–5408 (1997).
    [CrossRef]
  2. I. Akasaki and C. Wetzel, “Future challenges and directions for nitride materials and light emitters,” Proc. IEEE 85, 1750–1751 (1997).
    [CrossRef]
  3. Y. Kuwahara, T. Fujii, T. Sugiyama, D. Iida, Y. Isobe, Y. Fujiyama, Y. Morita, M. Iwaya, T. Takeuchi, S. Kamiyama, I. Akasaki, and H. Amano, “GaInN-based solar cells using strained-layer GaInN/GaInN superlattice active layer on a freestanding GaN substrate,” Appl. Phys. Express 4, 021001(2011).
    [CrossRef]
  4. S. Nakamura, M. Senoh, and T. Mukai, “Highly p-typed Mg-doped GaN films grown with GaN buffer layers,” Jpn. J. Appl. Phys. 30, L1708 (1991).
    [CrossRef]
  5. W. Götz, N. M. Johnson, J. Walker, D. P. Bour, and R. A. Street, “Activation of acceptors in Mg-doped GaN grown by metalorganic chemical vapor deposition,” Appl. Phys. Lett. 68, 667–669 (1996).
    [CrossRef]
  6. A. Mao, J. Cho, E. F. Schubert, J. K. Son, C. Sone, W. J. Ha, S. Hwang, and J. K. Kim, “Reduction of efficiency droop in GaInN/GaN light-emitting diodes with thick AlGaN cladding layers,” Electron. Mater. Lett. 8, 1–4 (2012).
    [CrossRef]
  7. J. W. Orton, “Acceptor binding energy in GaN and related alloys,” Semicond. Sci. Technol. 10, 101–104 (1995).
    [CrossRef]
  8. Y. Koide, H. Ishikawa, S. Kobayashi, S. Yamasaki, S. Nagai, J. Umezaki, M. Koike, and M. Murakami, “Dependence of electrical properties on work functions of metals contacting to p-type GaN,” Appl. Surf. Sci. 117/118, 373–379 (1997).
    [CrossRef]
  9. J. K. Sheu, Y. K. Su, G. C. Chi, P. L. Koh, M. J. Jou, C. M. Chang, C. C. Liu, and W. C. Hung, “High-transparency Ni/Au ohmic contact to p-type GaN,” Appl. Phys. Lett. 74, 2340–2342 (1999).
    [CrossRef]
  10. Y. C. Lin, S. J. Chang, Y. K. Su, T. Y. Tsai, C. S. Chang, S. C. Shei, C. W. Kuo, and S. C. Chen, “InGaN/GaN light emitting diodes with Ni/Au, Ni/ITO and ITO p-type contacts,” Solid-State Electron. 47, 849–853 (2003).
    [CrossRef]
  11. J. K. Ho, C. S. Jong, C. C. Chiu, C. N. Huang, K. K. Shih, L. C. Chen, F. R. Chen, and J. J. Kai, “Low-resistance ohmic contacts to p-type GaN achieved by the oxidation of Ni/Au films,” J. Appl. Phys. 86, 4491–4497 (1999).
    [CrossRef]
  12. T. Margalith, O. Buchinsky, D. A. Cohen, A. C. Abare, M. Hansen, S. P. DenBaars, and L. A. Coldren, “Indium tin oxide contacts to gallium nitride optoelectronic devices,” Appl. Phys. Lett. 74, 3930–3932 (1999).
    [CrossRef]
  13. D. W. Kim, Y. J. Sung, J. W. Park, and G. Y. Yeom, “A study of transparent indium tin oxide (ITO) contact to p-GaN,” Thin Solid Films 398/399, 87–92 (2001).
    [CrossRef]
  14. H. H. Berger, “Models for contacts to planar devices,” Solid-State Electron. 15, 145–158 (1972).
    [CrossRef]
  15. A. Weimar, A. Lell, G. Brüderl, S. Bader, and V. Härle, “Investigation of low-resistance metal contacts on p-type GaN using the linear and circular transmission line method,” Phys. Stat. Sol. (a) 183, 169–175 (2001).
    [CrossRef]
  16. L. Lewis, P. P. Maaskant, and B. Corbett, “On the specific contact resistance of metal contacts to p-type GaN,” Semicond. Sci. Technol. 21, 1738–1742 (2006).
    [CrossRef]
  17. Deepak and H. Krishna, “Measurement of small specific contact resistance of metals with resistive semiconductors,” J. Electron. Mater. 36, 598–605 (2007).
    [CrossRef]
  18. J. O. Song, D. S. Leem, J. S. Kwak, O. H. Nam, Y. Park, and T. Y. Seong, “Low-resistance and highly-reflective Zn–Ni solid solution/Ag ohmic contacts for flip-chip light-emitting diodes,” Appl. Phys. Lett. 83, 4990–4992 (2003).
    [CrossRef]
  19. T. Margalith, O. Buchinsky, D. A. Cohen, A. C. Abare, M. Hansen, S. P. DenBaars, and L. A. Coldren, “Indium tin oxide contacts to gallium nitride optoelectronic devices,” Appl. Phys. Lett. 74, 3930–3932 (1999).
    [CrossRef]
  20. D. W. Kim, Y. J. Sung, J. W. Park, and G. Y. Yeom, “A study of transparent indium tin oxide (ITO) contact to p-GaN,” Thin Solid Films 398/399, 87–92 (2001).
    [CrossRef]
  21. R.-H. Horng, D.-S. Wuu, Y.-C. Lien, and W.-H. Lan, “Low-resistance and high-transparency Ni/indium tin oxide ohmic contacts to p-type GaN,” Appl. Phys. Lett. 79, 2925–2927 (2001).
    [CrossRef]
  22. S.-M. Pan, R.-C. Tu, Y.-M. Fan, R.-C. Yeh, and J.-T. Hsu, “Enhanced output power of InGaN-GaN light-emitting diodes with high-transparency nickel-oxide-indium-tin-oxide ohmic contacts,” IEEE Photon. Technol. Lett. 15, 646–648 (2003).
  23. S. W. Chae, K. C. Kim, D. H. Kim, T. G. Kim, S. K. Yoon, B. W. Oh, D. S. Kim, H. K. Kim, and Y. M. Sung, “Highly transparent and low-resistant ZnNi/indium tin oxide ohmic contact on p-type GaN,” Appl. Phys. Lett. 90, 181101 (2007).
    [CrossRef]
  24. J.-O. Song, D.-S. Leem, J. S. Kwak, Y. Park, S. W. Chae, and T.-Y. Seong, “Improvement of the luminous intensity of light-emitting diodes by using highly transparent Ag-indium tin oxide p-type ohmic contacts,” IEEE Photon. Technol. Lett. 17, 291–293 (2005).
    [CrossRef]
  25. I. Hambergend and C. G. Granquist, “Evaporated Sn-doped In2O3 films: Basic optical properties and applications to energy-efficient windows,” J. Appl. Phys. 60, R123–R160 (1986).
    [CrossRef]
  26. M. J. Alam and D. C. Cameron, “Optical and electrical properties of transparent conductive ITO thin films deposited by sol–gel process,” Thin Solid Films 377/378, 455–459 (2000).
    [CrossRef]
  27. S. Boycheva, A. K. Sytchkovab, and A. Piegari, “Optical and electrical characterization of r.f. sputtered ITO films developed as art protection coatings,” Thin Solid Films 515, 8474–8478 (2007).
    [CrossRef]
  28. J. Szczyrbowski, A. Dietrich, and H. Hoffmann, “Optical and electrical properties of RF-sputtered indium–tin oxide films,” Phys. Status Solidi A 78, 243–252 (1983).
    [CrossRef]
  29. As determined by spectroscopic ellipsometry on a 67 nm ITO layer on Si.

2012 (1)

A. Mao, J. Cho, E. F. Schubert, J. K. Son, C. Sone, W. J. Ha, S. Hwang, and J. K. Kim, “Reduction of efficiency droop in GaInN/GaN light-emitting diodes with thick AlGaN cladding layers,” Electron. Mater. Lett. 8, 1–4 (2012).
[CrossRef]

2011 (1)

Y. Kuwahara, T. Fujii, T. Sugiyama, D. Iida, Y. Isobe, Y. Fujiyama, Y. Morita, M. Iwaya, T. Takeuchi, S. Kamiyama, I. Akasaki, and H. Amano, “GaInN-based solar cells using strained-layer GaInN/GaInN superlattice active layer on a freestanding GaN substrate,” Appl. Phys. Express 4, 021001(2011).
[CrossRef]

2007 (3)

Deepak and H. Krishna, “Measurement of small specific contact resistance of metals with resistive semiconductors,” J. Electron. Mater. 36, 598–605 (2007).
[CrossRef]

S. W. Chae, K. C. Kim, D. H. Kim, T. G. Kim, S. K. Yoon, B. W. Oh, D. S. Kim, H. K. Kim, and Y. M. Sung, “Highly transparent and low-resistant ZnNi/indium tin oxide ohmic contact on p-type GaN,” Appl. Phys. Lett. 90, 181101 (2007).
[CrossRef]

S. Boycheva, A. K. Sytchkovab, and A. Piegari, “Optical and electrical characterization of r.f. sputtered ITO films developed as art protection coatings,” Thin Solid Films 515, 8474–8478 (2007).
[CrossRef]

2006 (1)

L. Lewis, P. P. Maaskant, and B. Corbett, “On the specific contact resistance of metal contacts to p-type GaN,” Semicond. Sci. Technol. 21, 1738–1742 (2006).
[CrossRef]

2005 (1)

J.-O. Song, D.-S. Leem, J. S. Kwak, Y. Park, S. W. Chae, and T.-Y. Seong, “Improvement of the luminous intensity of light-emitting diodes by using highly transparent Ag-indium tin oxide p-type ohmic contacts,” IEEE Photon. Technol. Lett. 17, 291–293 (2005).
[CrossRef]

2003 (3)

S.-M. Pan, R.-C. Tu, Y.-M. Fan, R.-C. Yeh, and J.-T. Hsu, “Enhanced output power of InGaN-GaN light-emitting diodes with high-transparency nickel-oxide-indium-tin-oxide ohmic contacts,” IEEE Photon. Technol. Lett. 15, 646–648 (2003).

J. O. Song, D. S. Leem, J. S. Kwak, O. H. Nam, Y. Park, and T. Y. Seong, “Low-resistance and highly-reflective Zn–Ni solid solution/Ag ohmic contacts for flip-chip light-emitting diodes,” Appl. Phys. Lett. 83, 4990–4992 (2003).
[CrossRef]

Y. C. Lin, S. J. Chang, Y. K. Su, T. Y. Tsai, C. S. Chang, S. C. Shei, C. W. Kuo, and S. C. Chen, “InGaN/GaN light emitting diodes with Ni/Au, Ni/ITO and ITO p-type contacts,” Solid-State Electron. 47, 849–853 (2003).
[CrossRef]

2001 (4)

D. W. Kim, Y. J. Sung, J. W. Park, and G. Y. Yeom, “A study of transparent indium tin oxide (ITO) contact to p-GaN,” Thin Solid Films 398/399, 87–92 (2001).
[CrossRef]

A. Weimar, A. Lell, G. Brüderl, S. Bader, and V. Härle, “Investigation of low-resistance metal contacts on p-type GaN using the linear and circular transmission line method,” Phys. Stat. Sol. (a) 183, 169–175 (2001).
[CrossRef]

D. W. Kim, Y. J. Sung, J. W. Park, and G. Y. Yeom, “A study of transparent indium tin oxide (ITO) contact to p-GaN,” Thin Solid Films 398/399, 87–92 (2001).
[CrossRef]

R.-H. Horng, D.-S. Wuu, Y.-C. Lien, and W.-H. Lan, “Low-resistance and high-transparency Ni/indium tin oxide ohmic contacts to p-type GaN,” Appl. Phys. Lett. 79, 2925–2927 (2001).
[CrossRef]

2000 (1)

M. J. Alam and D. C. Cameron, “Optical and electrical properties of transparent conductive ITO thin films deposited by sol–gel process,” Thin Solid Films 377/378, 455–459 (2000).
[CrossRef]

1999 (4)

J. K. Sheu, Y. K. Su, G. C. Chi, P. L. Koh, M. J. Jou, C. M. Chang, C. C. Liu, and W. C. Hung, “High-transparency Ni/Au ohmic contact to p-type GaN,” Appl. Phys. Lett. 74, 2340–2342 (1999).
[CrossRef]

T. Margalith, O. Buchinsky, D. A. Cohen, A. C. Abare, M. Hansen, S. P. DenBaars, and L. A. Coldren, “Indium tin oxide contacts to gallium nitride optoelectronic devices,” Appl. Phys. Lett. 74, 3930–3932 (1999).
[CrossRef]

J. K. Ho, C. S. Jong, C. C. Chiu, C. N. Huang, K. K. Shih, L. C. Chen, F. R. Chen, and J. J. Kai, “Low-resistance ohmic contacts to p-type GaN achieved by the oxidation of Ni/Au films,” J. Appl. Phys. 86, 4491–4497 (1999).
[CrossRef]

T. Margalith, O. Buchinsky, D. A. Cohen, A. C. Abare, M. Hansen, S. P. DenBaars, and L. A. Coldren, “Indium tin oxide contacts to gallium nitride optoelectronic devices,” Appl. Phys. Lett. 74, 3930–3932 (1999).
[CrossRef]

1997 (3)

I. Akasaki and H. Amano, “Crystal growth and conductivity control of group III nitride semiconductors and their application to short wavelength light emitters,” Jpn. J. Appl. Phys. 36, 5393–5408 (1997).
[CrossRef]

I. Akasaki and C. Wetzel, “Future challenges and directions for nitride materials and light emitters,” Proc. IEEE 85, 1750–1751 (1997).
[CrossRef]

Y. Koide, H. Ishikawa, S. Kobayashi, S. Yamasaki, S. Nagai, J. Umezaki, M. Koike, and M. Murakami, “Dependence of electrical properties on work functions of metals contacting to p-type GaN,” Appl. Surf. Sci. 117/118, 373–379 (1997).
[CrossRef]

1996 (1)

W. Götz, N. M. Johnson, J. Walker, D. P. Bour, and R. A. Street, “Activation of acceptors in Mg-doped GaN grown by metalorganic chemical vapor deposition,” Appl. Phys. Lett. 68, 667–669 (1996).
[CrossRef]

1995 (1)

J. W. Orton, “Acceptor binding energy in GaN and related alloys,” Semicond. Sci. Technol. 10, 101–104 (1995).
[CrossRef]

1991 (1)

S. Nakamura, M. Senoh, and T. Mukai, “Highly p-typed Mg-doped GaN films grown with GaN buffer layers,” Jpn. J. Appl. Phys. 30, L1708 (1991).
[CrossRef]

1986 (1)

I. Hambergend and C. G. Granquist, “Evaporated Sn-doped In2O3 films: Basic optical properties and applications to energy-efficient windows,” J. Appl. Phys. 60, R123–R160 (1986).
[CrossRef]

1983 (1)

J. Szczyrbowski, A. Dietrich, and H. Hoffmann, “Optical and electrical properties of RF-sputtered indium–tin oxide films,” Phys. Status Solidi A 78, 243–252 (1983).
[CrossRef]

1972 (1)

H. H. Berger, “Models for contacts to planar devices,” Solid-State Electron. 15, 145–158 (1972).
[CrossRef]

Abare, A. C.

T. Margalith, O. Buchinsky, D. A. Cohen, A. C. Abare, M. Hansen, S. P. DenBaars, and L. A. Coldren, “Indium tin oxide contacts to gallium nitride optoelectronic devices,” Appl. Phys. Lett. 74, 3930–3932 (1999).
[CrossRef]

T. Margalith, O. Buchinsky, D. A. Cohen, A. C. Abare, M. Hansen, S. P. DenBaars, and L. A. Coldren, “Indium tin oxide contacts to gallium nitride optoelectronic devices,” Appl. Phys. Lett. 74, 3930–3932 (1999).
[CrossRef]

Akasaki, I.

Y. Kuwahara, T. Fujii, T. Sugiyama, D. Iida, Y. Isobe, Y. Fujiyama, Y. Morita, M. Iwaya, T. Takeuchi, S. Kamiyama, I. Akasaki, and H. Amano, “GaInN-based solar cells using strained-layer GaInN/GaInN superlattice active layer on a freestanding GaN substrate,” Appl. Phys. Express 4, 021001(2011).
[CrossRef]

I. Akasaki and H. Amano, “Crystal growth and conductivity control of group III nitride semiconductors and their application to short wavelength light emitters,” Jpn. J. Appl. Phys. 36, 5393–5408 (1997).
[CrossRef]

I. Akasaki and C. Wetzel, “Future challenges and directions for nitride materials and light emitters,” Proc. IEEE 85, 1750–1751 (1997).
[CrossRef]

Alam, M. J.

M. J. Alam and D. C. Cameron, “Optical and electrical properties of transparent conductive ITO thin films deposited by sol–gel process,” Thin Solid Films 377/378, 455–459 (2000).
[CrossRef]

Amano, H.

Y. Kuwahara, T. Fujii, T. Sugiyama, D. Iida, Y. Isobe, Y. Fujiyama, Y. Morita, M. Iwaya, T. Takeuchi, S. Kamiyama, I. Akasaki, and H. Amano, “GaInN-based solar cells using strained-layer GaInN/GaInN superlattice active layer on a freestanding GaN substrate,” Appl. Phys. Express 4, 021001(2011).
[CrossRef]

I. Akasaki and H. Amano, “Crystal growth and conductivity control of group III nitride semiconductors and their application to short wavelength light emitters,” Jpn. J. Appl. Phys. 36, 5393–5408 (1997).
[CrossRef]

Bader, S.

A. Weimar, A. Lell, G. Brüderl, S. Bader, and V. Härle, “Investigation of low-resistance metal contacts on p-type GaN using the linear and circular transmission line method,” Phys. Stat. Sol. (a) 183, 169–175 (2001).
[CrossRef]

Berger, H. H.

H. H. Berger, “Models for contacts to planar devices,” Solid-State Electron. 15, 145–158 (1972).
[CrossRef]

Bour, D. P.

W. Götz, N. M. Johnson, J. Walker, D. P. Bour, and R. A. Street, “Activation of acceptors in Mg-doped GaN grown by metalorganic chemical vapor deposition,” Appl. Phys. Lett. 68, 667–669 (1996).
[CrossRef]

Boycheva, S.

S. Boycheva, A. K. Sytchkovab, and A. Piegari, “Optical and electrical characterization of r.f. sputtered ITO films developed as art protection coatings,” Thin Solid Films 515, 8474–8478 (2007).
[CrossRef]

Brüderl, G.

A. Weimar, A. Lell, G. Brüderl, S. Bader, and V. Härle, “Investigation of low-resistance metal contacts on p-type GaN using the linear and circular transmission line method,” Phys. Stat. Sol. (a) 183, 169–175 (2001).
[CrossRef]

Buchinsky, O.

T. Margalith, O. Buchinsky, D. A. Cohen, A. C. Abare, M. Hansen, S. P. DenBaars, and L. A. Coldren, “Indium tin oxide contacts to gallium nitride optoelectronic devices,” Appl. Phys. Lett. 74, 3930–3932 (1999).
[CrossRef]

T. Margalith, O. Buchinsky, D. A. Cohen, A. C. Abare, M. Hansen, S. P. DenBaars, and L. A. Coldren, “Indium tin oxide contacts to gallium nitride optoelectronic devices,” Appl. Phys. Lett. 74, 3930–3932 (1999).
[CrossRef]

Cameron, D. C.

M. J. Alam and D. C. Cameron, “Optical and electrical properties of transparent conductive ITO thin films deposited by sol–gel process,” Thin Solid Films 377/378, 455–459 (2000).
[CrossRef]

Chae, S. W.

S. W. Chae, K. C. Kim, D. H. Kim, T. G. Kim, S. K. Yoon, B. W. Oh, D. S. Kim, H. K. Kim, and Y. M. Sung, “Highly transparent and low-resistant ZnNi/indium tin oxide ohmic contact on p-type GaN,” Appl. Phys. Lett. 90, 181101 (2007).
[CrossRef]

J.-O. Song, D.-S. Leem, J. S. Kwak, Y. Park, S. W. Chae, and T.-Y. Seong, “Improvement of the luminous intensity of light-emitting diodes by using highly transparent Ag-indium tin oxide p-type ohmic contacts,” IEEE Photon. Technol. Lett. 17, 291–293 (2005).
[CrossRef]

Chang, C. M.

J. K. Sheu, Y. K. Su, G. C. Chi, P. L. Koh, M. J. Jou, C. M. Chang, C. C. Liu, and W. C. Hung, “High-transparency Ni/Au ohmic contact to p-type GaN,” Appl. Phys. Lett. 74, 2340–2342 (1999).
[CrossRef]

Chang, C. S.

Y. C. Lin, S. J. Chang, Y. K. Su, T. Y. Tsai, C. S. Chang, S. C. Shei, C. W. Kuo, and S. C. Chen, “InGaN/GaN light emitting diodes with Ni/Au, Ni/ITO and ITO p-type contacts,” Solid-State Electron. 47, 849–853 (2003).
[CrossRef]

Chang, S. J.

Y. C. Lin, S. J. Chang, Y. K. Su, T. Y. Tsai, C. S. Chang, S. C. Shei, C. W. Kuo, and S. C. Chen, “InGaN/GaN light emitting diodes with Ni/Au, Ni/ITO and ITO p-type contacts,” Solid-State Electron. 47, 849–853 (2003).
[CrossRef]

Chen, F. R.

J. K. Ho, C. S. Jong, C. C. Chiu, C. N. Huang, K. K. Shih, L. C. Chen, F. R. Chen, and J. J. Kai, “Low-resistance ohmic contacts to p-type GaN achieved by the oxidation of Ni/Au films,” J. Appl. Phys. 86, 4491–4497 (1999).
[CrossRef]

Chen, L. C.

J. K. Ho, C. S. Jong, C. C. Chiu, C. N. Huang, K. K. Shih, L. C. Chen, F. R. Chen, and J. J. Kai, “Low-resistance ohmic contacts to p-type GaN achieved by the oxidation of Ni/Au films,” J. Appl. Phys. 86, 4491–4497 (1999).
[CrossRef]

Chen, S. C.

Y. C. Lin, S. J. Chang, Y. K. Su, T. Y. Tsai, C. S. Chang, S. C. Shei, C. W. Kuo, and S. C. Chen, “InGaN/GaN light emitting diodes with Ni/Au, Ni/ITO and ITO p-type contacts,” Solid-State Electron. 47, 849–853 (2003).
[CrossRef]

Chi, G. C.

J. K. Sheu, Y. K. Su, G. C. Chi, P. L. Koh, M. J. Jou, C. M. Chang, C. C. Liu, and W. C. Hung, “High-transparency Ni/Au ohmic contact to p-type GaN,” Appl. Phys. Lett. 74, 2340–2342 (1999).
[CrossRef]

Chiu, C. C.

J. K. Ho, C. S. Jong, C. C. Chiu, C. N. Huang, K. K. Shih, L. C. Chen, F. R. Chen, and J. J. Kai, “Low-resistance ohmic contacts to p-type GaN achieved by the oxidation of Ni/Au films,” J. Appl. Phys. 86, 4491–4497 (1999).
[CrossRef]

Cho, J.

A. Mao, J. Cho, E. F. Schubert, J. K. Son, C. Sone, W. J. Ha, S. Hwang, and J. K. Kim, “Reduction of efficiency droop in GaInN/GaN light-emitting diodes with thick AlGaN cladding layers,” Electron. Mater. Lett. 8, 1–4 (2012).
[CrossRef]

Cohen, D. A.

T. Margalith, O. Buchinsky, D. A. Cohen, A. C. Abare, M. Hansen, S. P. DenBaars, and L. A. Coldren, “Indium tin oxide contacts to gallium nitride optoelectronic devices,” Appl. Phys. Lett. 74, 3930–3932 (1999).
[CrossRef]

T. Margalith, O. Buchinsky, D. A. Cohen, A. C. Abare, M. Hansen, S. P. DenBaars, and L. A. Coldren, “Indium tin oxide contacts to gallium nitride optoelectronic devices,” Appl. Phys. Lett. 74, 3930–3932 (1999).
[CrossRef]

Coldren, L. A.

T. Margalith, O. Buchinsky, D. A. Cohen, A. C. Abare, M. Hansen, S. P. DenBaars, and L. A. Coldren, “Indium tin oxide contacts to gallium nitride optoelectronic devices,” Appl. Phys. Lett. 74, 3930–3932 (1999).
[CrossRef]

T. Margalith, O. Buchinsky, D. A. Cohen, A. C. Abare, M. Hansen, S. P. DenBaars, and L. A. Coldren, “Indium tin oxide contacts to gallium nitride optoelectronic devices,” Appl. Phys. Lett. 74, 3930–3932 (1999).
[CrossRef]

Corbett, B.

L. Lewis, P. P. Maaskant, and B. Corbett, “On the specific contact resistance of metal contacts to p-type GaN,” Semicond. Sci. Technol. 21, 1738–1742 (2006).
[CrossRef]

Deepak,

Deepak and H. Krishna, “Measurement of small specific contact resistance of metals with resistive semiconductors,” J. Electron. Mater. 36, 598–605 (2007).
[CrossRef]

DenBaars, S. P.

T. Margalith, O. Buchinsky, D. A. Cohen, A. C. Abare, M. Hansen, S. P. DenBaars, and L. A. Coldren, “Indium tin oxide contacts to gallium nitride optoelectronic devices,” Appl. Phys. Lett. 74, 3930–3932 (1999).
[CrossRef]

T. Margalith, O. Buchinsky, D. A. Cohen, A. C. Abare, M. Hansen, S. P. DenBaars, and L. A. Coldren, “Indium tin oxide contacts to gallium nitride optoelectronic devices,” Appl. Phys. Lett. 74, 3930–3932 (1999).
[CrossRef]

Dietrich, A.

J. Szczyrbowski, A. Dietrich, and H. Hoffmann, “Optical and electrical properties of RF-sputtered indium–tin oxide films,” Phys. Status Solidi A 78, 243–252 (1983).
[CrossRef]

Fan, Y.-M.

S.-M. Pan, R.-C. Tu, Y.-M. Fan, R.-C. Yeh, and J.-T. Hsu, “Enhanced output power of InGaN-GaN light-emitting diodes with high-transparency nickel-oxide-indium-tin-oxide ohmic contacts,” IEEE Photon. Technol. Lett. 15, 646–648 (2003).

Fujii, T.

Y. Kuwahara, T. Fujii, T. Sugiyama, D. Iida, Y. Isobe, Y. Fujiyama, Y. Morita, M. Iwaya, T. Takeuchi, S. Kamiyama, I. Akasaki, and H. Amano, “GaInN-based solar cells using strained-layer GaInN/GaInN superlattice active layer on a freestanding GaN substrate,” Appl. Phys. Express 4, 021001(2011).
[CrossRef]

Fujiyama, Y.

Y. Kuwahara, T. Fujii, T. Sugiyama, D. Iida, Y. Isobe, Y. Fujiyama, Y. Morita, M. Iwaya, T. Takeuchi, S. Kamiyama, I. Akasaki, and H. Amano, “GaInN-based solar cells using strained-layer GaInN/GaInN superlattice active layer on a freestanding GaN substrate,” Appl. Phys. Express 4, 021001(2011).
[CrossRef]

Götz, W.

W. Götz, N. M. Johnson, J. Walker, D. P. Bour, and R. A. Street, “Activation of acceptors in Mg-doped GaN grown by metalorganic chemical vapor deposition,” Appl. Phys. Lett. 68, 667–669 (1996).
[CrossRef]

Granquist, C. G.

I. Hambergend and C. G. Granquist, “Evaporated Sn-doped In2O3 films: Basic optical properties and applications to energy-efficient windows,” J. Appl. Phys. 60, R123–R160 (1986).
[CrossRef]

Ha, W. J.

A. Mao, J. Cho, E. F. Schubert, J. K. Son, C. Sone, W. J. Ha, S. Hwang, and J. K. Kim, “Reduction of efficiency droop in GaInN/GaN light-emitting diodes with thick AlGaN cladding layers,” Electron. Mater. Lett. 8, 1–4 (2012).
[CrossRef]

Hambergend, I.

I. Hambergend and C. G. Granquist, “Evaporated Sn-doped In2O3 films: Basic optical properties and applications to energy-efficient windows,” J. Appl. Phys. 60, R123–R160 (1986).
[CrossRef]

Hansen, M.

T. Margalith, O. Buchinsky, D. A. Cohen, A. C. Abare, M. Hansen, S. P. DenBaars, and L. A. Coldren, “Indium tin oxide contacts to gallium nitride optoelectronic devices,” Appl. Phys. Lett. 74, 3930–3932 (1999).
[CrossRef]

T. Margalith, O. Buchinsky, D. A. Cohen, A. C. Abare, M. Hansen, S. P. DenBaars, and L. A. Coldren, “Indium tin oxide contacts to gallium nitride optoelectronic devices,” Appl. Phys. Lett. 74, 3930–3932 (1999).
[CrossRef]

Härle, V.

A. Weimar, A. Lell, G. Brüderl, S. Bader, and V. Härle, “Investigation of low-resistance metal contacts on p-type GaN using the linear and circular transmission line method,” Phys. Stat. Sol. (a) 183, 169–175 (2001).
[CrossRef]

Ho, J. K.

J. K. Ho, C. S. Jong, C. C. Chiu, C. N. Huang, K. K. Shih, L. C. Chen, F. R. Chen, and J. J. Kai, “Low-resistance ohmic contacts to p-type GaN achieved by the oxidation of Ni/Au films,” J. Appl. Phys. 86, 4491–4497 (1999).
[CrossRef]

Hoffmann, H.

J. Szczyrbowski, A. Dietrich, and H. Hoffmann, “Optical and electrical properties of RF-sputtered indium–tin oxide films,” Phys. Status Solidi A 78, 243–252 (1983).
[CrossRef]

Horng, R.-H.

R.-H. Horng, D.-S. Wuu, Y.-C. Lien, and W.-H. Lan, “Low-resistance and high-transparency Ni/indium tin oxide ohmic contacts to p-type GaN,” Appl. Phys. Lett. 79, 2925–2927 (2001).
[CrossRef]

Hsu, J.-T.

S.-M. Pan, R.-C. Tu, Y.-M. Fan, R.-C. Yeh, and J.-T. Hsu, “Enhanced output power of InGaN-GaN light-emitting diodes with high-transparency nickel-oxide-indium-tin-oxide ohmic contacts,” IEEE Photon. Technol. Lett. 15, 646–648 (2003).

Huang, C. N.

J. K. Ho, C. S. Jong, C. C. Chiu, C. N. Huang, K. K. Shih, L. C. Chen, F. R. Chen, and J. J. Kai, “Low-resistance ohmic contacts to p-type GaN achieved by the oxidation of Ni/Au films,” J. Appl. Phys. 86, 4491–4497 (1999).
[CrossRef]

Hung, W. C.

J. K. Sheu, Y. K. Su, G. C. Chi, P. L. Koh, M. J. Jou, C. M. Chang, C. C. Liu, and W. C. Hung, “High-transparency Ni/Au ohmic contact to p-type GaN,” Appl. Phys. Lett. 74, 2340–2342 (1999).
[CrossRef]

Hwang, S.

A. Mao, J. Cho, E. F. Schubert, J. K. Son, C. Sone, W. J. Ha, S. Hwang, and J. K. Kim, “Reduction of efficiency droop in GaInN/GaN light-emitting diodes with thick AlGaN cladding layers,” Electron. Mater. Lett. 8, 1–4 (2012).
[CrossRef]

Iida, D.

Y. Kuwahara, T. Fujii, T. Sugiyama, D. Iida, Y. Isobe, Y. Fujiyama, Y. Morita, M. Iwaya, T. Takeuchi, S. Kamiyama, I. Akasaki, and H. Amano, “GaInN-based solar cells using strained-layer GaInN/GaInN superlattice active layer on a freestanding GaN substrate,” Appl. Phys. Express 4, 021001(2011).
[CrossRef]

Ishikawa, H.

Y. Koide, H. Ishikawa, S. Kobayashi, S. Yamasaki, S. Nagai, J. Umezaki, M. Koike, and M. Murakami, “Dependence of electrical properties on work functions of metals contacting to p-type GaN,” Appl. Surf. Sci. 117/118, 373–379 (1997).
[CrossRef]

Isobe, Y.

Y. Kuwahara, T. Fujii, T. Sugiyama, D. Iida, Y. Isobe, Y. Fujiyama, Y. Morita, M. Iwaya, T. Takeuchi, S. Kamiyama, I. Akasaki, and H. Amano, “GaInN-based solar cells using strained-layer GaInN/GaInN superlattice active layer on a freestanding GaN substrate,” Appl. Phys. Express 4, 021001(2011).
[CrossRef]

Iwaya, M.

Y. Kuwahara, T. Fujii, T. Sugiyama, D. Iida, Y. Isobe, Y. Fujiyama, Y. Morita, M. Iwaya, T. Takeuchi, S. Kamiyama, I. Akasaki, and H. Amano, “GaInN-based solar cells using strained-layer GaInN/GaInN superlattice active layer on a freestanding GaN substrate,” Appl. Phys. Express 4, 021001(2011).
[CrossRef]

Johnson, N. M.

W. Götz, N. M. Johnson, J. Walker, D. P. Bour, and R. A. Street, “Activation of acceptors in Mg-doped GaN grown by metalorganic chemical vapor deposition,” Appl. Phys. Lett. 68, 667–669 (1996).
[CrossRef]

Jong, C. S.

J. K. Ho, C. S. Jong, C. C. Chiu, C. N. Huang, K. K. Shih, L. C. Chen, F. R. Chen, and J. J. Kai, “Low-resistance ohmic contacts to p-type GaN achieved by the oxidation of Ni/Au films,” J. Appl. Phys. 86, 4491–4497 (1999).
[CrossRef]

Jou, M. J.

J. K. Sheu, Y. K. Su, G. C. Chi, P. L. Koh, M. J. Jou, C. M. Chang, C. C. Liu, and W. C. Hung, “High-transparency Ni/Au ohmic contact to p-type GaN,” Appl. Phys. Lett. 74, 2340–2342 (1999).
[CrossRef]

Kai, J. J.

J. K. Ho, C. S. Jong, C. C. Chiu, C. N. Huang, K. K. Shih, L. C. Chen, F. R. Chen, and J. J. Kai, “Low-resistance ohmic contacts to p-type GaN achieved by the oxidation of Ni/Au films,” J. Appl. Phys. 86, 4491–4497 (1999).
[CrossRef]

Kamiyama, S.

Y. Kuwahara, T. Fujii, T. Sugiyama, D. Iida, Y. Isobe, Y. Fujiyama, Y. Morita, M. Iwaya, T. Takeuchi, S. Kamiyama, I. Akasaki, and H. Amano, “GaInN-based solar cells using strained-layer GaInN/GaInN superlattice active layer on a freestanding GaN substrate,” Appl. Phys. Express 4, 021001(2011).
[CrossRef]

Kim, D. H.

S. W. Chae, K. C. Kim, D. H. Kim, T. G. Kim, S. K. Yoon, B. W. Oh, D. S. Kim, H. K. Kim, and Y. M. Sung, “Highly transparent and low-resistant ZnNi/indium tin oxide ohmic contact on p-type GaN,” Appl. Phys. Lett. 90, 181101 (2007).
[CrossRef]

Kim, D. S.

S. W. Chae, K. C. Kim, D. H. Kim, T. G. Kim, S. K. Yoon, B. W. Oh, D. S. Kim, H. K. Kim, and Y. M. Sung, “Highly transparent and low-resistant ZnNi/indium tin oxide ohmic contact on p-type GaN,” Appl. Phys. Lett. 90, 181101 (2007).
[CrossRef]

Kim, D. W.

D. W. Kim, Y. J. Sung, J. W. Park, and G. Y. Yeom, “A study of transparent indium tin oxide (ITO) contact to p-GaN,” Thin Solid Films 398/399, 87–92 (2001).
[CrossRef]

D. W. Kim, Y. J. Sung, J. W. Park, and G. Y. Yeom, “A study of transparent indium tin oxide (ITO) contact to p-GaN,” Thin Solid Films 398/399, 87–92 (2001).
[CrossRef]

Kim, H. K.

S. W. Chae, K. C. Kim, D. H. Kim, T. G. Kim, S. K. Yoon, B. W. Oh, D. S. Kim, H. K. Kim, and Y. M. Sung, “Highly transparent and low-resistant ZnNi/indium tin oxide ohmic contact on p-type GaN,” Appl. Phys. Lett. 90, 181101 (2007).
[CrossRef]

Kim, J. K.

A. Mao, J. Cho, E. F. Schubert, J. K. Son, C. Sone, W. J. Ha, S. Hwang, and J. K. Kim, “Reduction of efficiency droop in GaInN/GaN light-emitting diodes with thick AlGaN cladding layers,” Electron. Mater. Lett. 8, 1–4 (2012).
[CrossRef]

Kim, K. C.

S. W. Chae, K. C. Kim, D. H. Kim, T. G. Kim, S. K. Yoon, B. W. Oh, D. S. Kim, H. K. Kim, and Y. M. Sung, “Highly transparent and low-resistant ZnNi/indium tin oxide ohmic contact on p-type GaN,” Appl. Phys. Lett. 90, 181101 (2007).
[CrossRef]

Kim, T. G.

S. W. Chae, K. C. Kim, D. H. Kim, T. G. Kim, S. K. Yoon, B. W. Oh, D. S. Kim, H. K. Kim, and Y. M. Sung, “Highly transparent and low-resistant ZnNi/indium tin oxide ohmic contact on p-type GaN,” Appl. Phys. Lett. 90, 181101 (2007).
[CrossRef]

Kobayashi, S.

Y. Koide, H. Ishikawa, S. Kobayashi, S. Yamasaki, S. Nagai, J. Umezaki, M. Koike, and M. Murakami, “Dependence of electrical properties on work functions of metals contacting to p-type GaN,” Appl. Surf. Sci. 117/118, 373–379 (1997).
[CrossRef]

Koh, P. L.

J. K. Sheu, Y. K. Su, G. C. Chi, P. L. Koh, M. J. Jou, C. M. Chang, C. C. Liu, and W. C. Hung, “High-transparency Ni/Au ohmic contact to p-type GaN,” Appl. Phys. Lett. 74, 2340–2342 (1999).
[CrossRef]

Koide, Y.

Y. Koide, H. Ishikawa, S. Kobayashi, S. Yamasaki, S. Nagai, J. Umezaki, M. Koike, and M. Murakami, “Dependence of electrical properties on work functions of metals contacting to p-type GaN,” Appl. Surf. Sci. 117/118, 373–379 (1997).
[CrossRef]

Koike, M.

Y. Koide, H. Ishikawa, S. Kobayashi, S. Yamasaki, S. Nagai, J. Umezaki, M. Koike, and M. Murakami, “Dependence of electrical properties on work functions of metals contacting to p-type GaN,” Appl. Surf. Sci. 117/118, 373–379 (1997).
[CrossRef]

Krishna, H.

Deepak and H. Krishna, “Measurement of small specific contact resistance of metals with resistive semiconductors,” J. Electron. Mater. 36, 598–605 (2007).
[CrossRef]

Kuo, C. W.

Y. C. Lin, S. J. Chang, Y. K. Su, T. Y. Tsai, C. S. Chang, S. C. Shei, C. W. Kuo, and S. C. Chen, “InGaN/GaN light emitting diodes with Ni/Au, Ni/ITO and ITO p-type contacts,” Solid-State Electron. 47, 849–853 (2003).
[CrossRef]

Kuwahara, Y.

Y. Kuwahara, T. Fujii, T. Sugiyama, D. Iida, Y. Isobe, Y. Fujiyama, Y. Morita, M. Iwaya, T. Takeuchi, S. Kamiyama, I. Akasaki, and H. Amano, “GaInN-based solar cells using strained-layer GaInN/GaInN superlattice active layer on a freestanding GaN substrate,” Appl. Phys. Express 4, 021001(2011).
[CrossRef]

Kwak, J. S.

J.-O. Song, D.-S. Leem, J. S. Kwak, Y. Park, S. W. Chae, and T.-Y. Seong, “Improvement of the luminous intensity of light-emitting diodes by using highly transparent Ag-indium tin oxide p-type ohmic contacts,” IEEE Photon. Technol. Lett. 17, 291–293 (2005).
[CrossRef]

J. O. Song, D. S. Leem, J. S. Kwak, O. H. Nam, Y. Park, and T. Y. Seong, “Low-resistance and highly-reflective Zn–Ni solid solution/Ag ohmic contacts for flip-chip light-emitting diodes,” Appl. Phys. Lett. 83, 4990–4992 (2003).
[CrossRef]

Lan, W.-H.

R.-H. Horng, D.-S. Wuu, Y.-C. Lien, and W.-H. Lan, “Low-resistance and high-transparency Ni/indium tin oxide ohmic contacts to p-type GaN,” Appl. Phys. Lett. 79, 2925–2927 (2001).
[CrossRef]

Leem, D. S.

J. O. Song, D. S. Leem, J. S. Kwak, O. H. Nam, Y. Park, and T. Y. Seong, “Low-resistance and highly-reflective Zn–Ni solid solution/Ag ohmic contacts for flip-chip light-emitting diodes,” Appl. Phys. Lett. 83, 4990–4992 (2003).
[CrossRef]

Leem, D.-S.

J.-O. Song, D.-S. Leem, J. S. Kwak, Y. Park, S. W. Chae, and T.-Y. Seong, “Improvement of the luminous intensity of light-emitting diodes by using highly transparent Ag-indium tin oxide p-type ohmic contacts,” IEEE Photon. Technol. Lett. 17, 291–293 (2005).
[CrossRef]

Lell, A.

A. Weimar, A. Lell, G. Brüderl, S. Bader, and V. Härle, “Investigation of low-resistance metal contacts on p-type GaN using the linear and circular transmission line method,” Phys. Stat. Sol. (a) 183, 169–175 (2001).
[CrossRef]

Lewis, L.

L. Lewis, P. P. Maaskant, and B. Corbett, “On the specific contact resistance of metal contacts to p-type GaN,” Semicond. Sci. Technol. 21, 1738–1742 (2006).
[CrossRef]

Lien, Y.-C.

R.-H. Horng, D.-S. Wuu, Y.-C. Lien, and W.-H. Lan, “Low-resistance and high-transparency Ni/indium tin oxide ohmic contacts to p-type GaN,” Appl. Phys. Lett. 79, 2925–2927 (2001).
[CrossRef]

Lin, Y. C.

Y. C. Lin, S. J. Chang, Y. K. Su, T. Y. Tsai, C. S. Chang, S. C. Shei, C. W. Kuo, and S. C. Chen, “InGaN/GaN light emitting diodes with Ni/Au, Ni/ITO and ITO p-type contacts,” Solid-State Electron. 47, 849–853 (2003).
[CrossRef]

Liu, C. C.

J. K. Sheu, Y. K. Su, G. C. Chi, P. L. Koh, M. J. Jou, C. M. Chang, C. C. Liu, and W. C. Hung, “High-transparency Ni/Au ohmic contact to p-type GaN,” Appl. Phys. Lett. 74, 2340–2342 (1999).
[CrossRef]

Maaskant, P. P.

L. Lewis, P. P. Maaskant, and B. Corbett, “On the specific contact resistance of metal contacts to p-type GaN,” Semicond. Sci. Technol. 21, 1738–1742 (2006).
[CrossRef]

Mao, A.

A. Mao, J. Cho, E. F. Schubert, J. K. Son, C. Sone, W. J. Ha, S. Hwang, and J. K. Kim, “Reduction of efficiency droop in GaInN/GaN light-emitting diodes with thick AlGaN cladding layers,” Electron. Mater. Lett. 8, 1–4 (2012).
[CrossRef]

Margalith, T.

T. Margalith, O. Buchinsky, D. A. Cohen, A. C. Abare, M. Hansen, S. P. DenBaars, and L. A. Coldren, “Indium tin oxide contacts to gallium nitride optoelectronic devices,” Appl. Phys. Lett. 74, 3930–3932 (1999).
[CrossRef]

T. Margalith, O. Buchinsky, D. A. Cohen, A. C. Abare, M. Hansen, S. P. DenBaars, and L. A. Coldren, “Indium tin oxide contacts to gallium nitride optoelectronic devices,” Appl. Phys. Lett. 74, 3930–3932 (1999).
[CrossRef]

Morita, Y.

Y. Kuwahara, T. Fujii, T. Sugiyama, D. Iida, Y. Isobe, Y. Fujiyama, Y. Morita, M. Iwaya, T. Takeuchi, S. Kamiyama, I. Akasaki, and H. Amano, “GaInN-based solar cells using strained-layer GaInN/GaInN superlattice active layer on a freestanding GaN substrate,” Appl. Phys. Express 4, 021001(2011).
[CrossRef]

Mukai, T.

S. Nakamura, M. Senoh, and T. Mukai, “Highly p-typed Mg-doped GaN films grown with GaN buffer layers,” Jpn. J. Appl. Phys. 30, L1708 (1991).
[CrossRef]

Murakami, M.

Y. Koide, H. Ishikawa, S. Kobayashi, S. Yamasaki, S. Nagai, J. Umezaki, M. Koike, and M. Murakami, “Dependence of electrical properties on work functions of metals contacting to p-type GaN,” Appl. Surf. Sci. 117/118, 373–379 (1997).
[CrossRef]

Nagai, S.

Y. Koide, H. Ishikawa, S. Kobayashi, S. Yamasaki, S. Nagai, J. Umezaki, M. Koike, and M. Murakami, “Dependence of electrical properties on work functions of metals contacting to p-type GaN,” Appl. Surf. Sci. 117/118, 373–379 (1997).
[CrossRef]

Nakamura, S.

S. Nakamura, M. Senoh, and T. Mukai, “Highly p-typed Mg-doped GaN films grown with GaN buffer layers,” Jpn. J. Appl. Phys. 30, L1708 (1991).
[CrossRef]

Nam, O. H.

J. O. Song, D. S. Leem, J. S. Kwak, O. H. Nam, Y. Park, and T. Y. Seong, “Low-resistance and highly-reflective Zn–Ni solid solution/Ag ohmic contacts for flip-chip light-emitting diodes,” Appl. Phys. Lett. 83, 4990–4992 (2003).
[CrossRef]

Oh, B. W.

S. W. Chae, K. C. Kim, D. H. Kim, T. G. Kim, S. K. Yoon, B. W. Oh, D. S. Kim, H. K. Kim, and Y. M. Sung, “Highly transparent and low-resistant ZnNi/indium tin oxide ohmic contact on p-type GaN,” Appl. Phys. Lett. 90, 181101 (2007).
[CrossRef]

Orton, J. W.

J. W. Orton, “Acceptor binding energy in GaN and related alloys,” Semicond. Sci. Technol. 10, 101–104 (1995).
[CrossRef]

Pan, S.-M.

S.-M. Pan, R.-C. Tu, Y.-M. Fan, R.-C. Yeh, and J.-T. Hsu, “Enhanced output power of InGaN-GaN light-emitting diodes with high-transparency nickel-oxide-indium-tin-oxide ohmic contacts,” IEEE Photon. Technol. Lett. 15, 646–648 (2003).

Park, J. W.

D. W. Kim, Y. J. Sung, J. W. Park, and G. Y. Yeom, “A study of transparent indium tin oxide (ITO) contact to p-GaN,” Thin Solid Films 398/399, 87–92 (2001).
[CrossRef]

D. W. Kim, Y. J. Sung, J. W. Park, and G. Y. Yeom, “A study of transparent indium tin oxide (ITO) contact to p-GaN,” Thin Solid Films 398/399, 87–92 (2001).
[CrossRef]

Park, Y.

J.-O. Song, D.-S. Leem, J. S. Kwak, Y. Park, S. W. Chae, and T.-Y. Seong, “Improvement of the luminous intensity of light-emitting diodes by using highly transparent Ag-indium tin oxide p-type ohmic contacts,” IEEE Photon. Technol. Lett. 17, 291–293 (2005).
[CrossRef]

J. O. Song, D. S. Leem, J. S. Kwak, O. H. Nam, Y. Park, and T. Y. Seong, “Low-resistance and highly-reflective Zn–Ni solid solution/Ag ohmic contacts for flip-chip light-emitting diodes,” Appl. Phys. Lett. 83, 4990–4992 (2003).
[CrossRef]

Piegari, A.

S. Boycheva, A. K. Sytchkovab, and A. Piegari, “Optical and electrical characterization of r.f. sputtered ITO films developed as art protection coatings,” Thin Solid Films 515, 8474–8478 (2007).
[CrossRef]

Schubert, E. F.

A. Mao, J. Cho, E. F. Schubert, J. K. Son, C. Sone, W. J. Ha, S. Hwang, and J. K. Kim, “Reduction of efficiency droop in GaInN/GaN light-emitting diodes with thick AlGaN cladding layers,” Electron. Mater. Lett. 8, 1–4 (2012).
[CrossRef]

Senoh, M.

S. Nakamura, M. Senoh, and T. Mukai, “Highly p-typed Mg-doped GaN films grown with GaN buffer layers,” Jpn. J. Appl. Phys. 30, L1708 (1991).
[CrossRef]

Seong, T. Y.

J. O. Song, D. S. Leem, J. S. Kwak, O. H. Nam, Y. Park, and T. Y. Seong, “Low-resistance and highly-reflective Zn–Ni solid solution/Ag ohmic contacts for flip-chip light-emitting diodes,” Appl. Phys. Lett. 83, 4990–4992 (2003).
[CrossRef]

Seong, T.-Y.

J.-O. Song, D.-S. Leem, J. S. Kwak, Y. Park, S. W. Chae, and T.-Y. Seong, “Improvement of the luminous intensity of light-emitting diodes by using highly transparent Ag-indium tin oxide p-type ohmic contacts,” IEEE Photon. Technol. Lett. 17, 291–293 (2005).
[CrossRef]

Shei, S. C.

Y. C. Lin, S. J. Chang, Y. K. Su, T. Y. Tsai, C. S. Chang, S. C. Shei, C. W. Kuo, and S. C. Chen, “InGaN/GaN light emitting diodes with Ni/Au, Ni/ITO and ITO p-type contacts,” Solid-State Electron. 47, 849–853 (2003).
[CrossRef]

Sheu, J. K.

J. K. Sheu, Y. K. Su, G. C. Chi, P. L. Koh, M. J. Jou, C. M. Chang, C. C. Liu, and W. C. Hung, “High-transparency Ni/Au ohmic contact to p-type GaN,” Appl. Phys. Lett. 74, 2340–2342 (1999).
[CrossRef]

Shih, K. K.

J. K. Ho, C. S. Jong, C. C. Chiu, C. N. Huang, K. K. Shih, L. C. Chen, F. R. Chen, and J. J. Kai, “Low-resistance ohmic contacts to p-type GaN achieved by the oxidation of Ni/Au films,” J. Appl. Phys. 86, 4491–4497 (1999).
[CrossRef]

Son, J. K.

A. Mao, J. Cho, E. F. Schubert, J. K. Son, C. Sone, W. J. Ha, S. Hwang, and J. K. Kim, “Reduction of efficiency droop in GaInN/GaN light-emitting diodes with thick AlGaN cladding layers,” Electron. Mater. Lett. 8, 1–4 (2012).
[CrossRef]

Sone, C.

A. Mao, J. Cho, E. F. Schubert, J. K. Son, C. Sone, W. J. Ha, S. Hwang, and J. K. Kim, “Reduction of efficiency droop in GaInN/GaN light-emitting diodes with thick AlGaN cladding layers,” Electron. Mater. Lett. 8, 1–4 (2012).
[CrossRef]

Song, J. O.

J. O. Song, D. S. Leem, J. S. Kwak, O. H. Nam, Y. Park, and T. Y. Seong, “Low-resistance and highly-reflective Zn–Ni solid solution/Ag ohmic contacts for flip-chip light-emitting diodes,” Appl. Phys. Lett. 83, 4990–4992 (2003).
[CrossRef]

Song, J.-O.

J.-O. Song, D.-S. Leem, J. S. Kwak, Y. Park, S. W. Chae, and T.-Y. Seong, “Improvement of the luminous intensity of light-emitting diodes by using highly transparent Ag-indium tin oxide p-type ohmic contacts,” IEEE Photon. Technol. Lett. 17, 291–293 (2005).
[CrossRef]

Street, R. A.

W. Götz, N. M. Johnson, J. Walker, D. P. Bour, and R. A. Street, “Activation of acceptors in Mg-doped GaN grown by metalorganic chemical vapor deposition,” Appl. Phys. Lett. 68, 667–669 (1996).
[CrossRef]

Su, Y. K.

Y. C. Lin, S. J. Chang, Y. K. Su, T. Y. Tsai, C. S. Chang, S. C. Shei, C. W. Kuo, and S. C. Chen, “InGaN/GaN light emitting diodes with Ni/Au, Ni/ITO and ITO p-type contacts,” Solid-State Electron. 47, 849–853 (2003).
[CrossRef]

J. K. Sheu, Y. K. Su, G. C. Chi, P. L. Koh, M. J. Jou, C. M. Chang, C. C. Liu, and W. C. Hung, “High-transparency Ni/Au ohmic contact to p-type GaN,” Appl. Phys. Lett. 74, 2340–2342 (1999).
[CrossRef]

Sugiyama, T.

Y. Kuwahara, T. Fujii, T. Sugiyama, D. Iida, Y. Isobe, Y. Fujiyama, Y. Morita, M. Iwaya, T. Takeuchi, S. Kamiyama, I. Akasaki, and H. Amano, “GaInN-based solar cells using strained-layer GaInN/GaInN superlattice active layer on a freestanding GaN substrate,” Appl. Phys. Express 4, 021001(2011).
[CrossRef]

Sung, Y. J.

D. W. Kim, Y. J. Sung, J. W. Park, and G. Y. Yeom, “A study of transparent indium tin oxide (ITO) contact to p-GaN,” Thin Solid Films 398/399, 87–92 (2001).
[CrossRef]

D. W. Kim, Y. J. Sung, J. W. Park, and G. Y. Yeom, “A study of transparent indium tin oxide (ITO) contact to p-GaN,” Thin Solid Films 398/399, 87–92 (2001).
[CrossRef]

Sung, Y. M.

S. W. Chae, K. C. Kim, D. H. Kim, T. G. Kim, S. K. Yoon, B. W. Oh, D. S. Kim, H. K. Kim, and Y. M. Sung, “Highly transparent and low-resistant ZnNi/indium tin oxide ohmic contact on p-type GaN,” Appl. Phys. Lett. 90, 181101 (2007).
[CrossRef]

Sytchkovab, A. K.

S. Boycheva, A. K. Sytchkovab, and A. Piegari, “Optical and electrical characterization of r.f. sputtered ITO films developed as art protection coatings,” Thin Solid Films 515, 8474–8478 (2007).
[CrossRef]

Szczyrbowski, J.

J. Szczyrbowski, A. Dietrich, and H. Hoffmann, “Optical and electrical properties of RF-sputtered indium–tin oxide films,” Phys. Status Solidi A 78, 243–252 (1983).
[CrossRef]

Takeuchi, T.

Y. Kuwahara, T. Fujii, T. Sugiyama, D. Iida, Y. Isobe, Y. Fujiyama, Y. Morita, M. Iwaya, T. Takeuchi, S. Kamiyama, I. Akasaki, and H. Amano, “GaInN-based solar cells using strained-layer GaInN/GaInN superlattice active layer on a freestanding GaN substrate,” Appl. Phys. Express 4, 021001(2011).
[CrossRef]

Tsai, T. Y.

Y. C. Lin, S. J. Chang, Y. K. Su, T. Y. Tsai, C. S. Chang, S. C. Shei, C. W. Kuo, and S. C. Chen, “InGaN/GaN light emitting diodes with Ni/Au, Ni/ITO and ITO p-type contacts,” Solid-State Electron. 47, 849–853 (2003).
[CrossRef]

Tu, R.-C.

S.-M. Pan, R.-C. Tu, Y.-M. Fan, R.-C. Yeh, and J.-T. Hsu, “Enhanced output power of InGaN-GaN light-emitting diodes with high-transparency nickel-oxide-indium-tin-oxide ohmic contacts,” IEEE Photon. Technol. Lett. 15, 646–648 (2003).

Umezaki, J.

Y. Koide, H. Ishikawa, S. Kobayashi, S. Yamasaki, S. Nagai, J. Umezaki, M. Koike, and M. Murakami, “Dependence of electrical properties on work functions of metals contacting to p-type GaN,” Appl. Surf. Sci. 117/118, 373–379 (1997).
[CrossRef]

Walker, J.

W. Götz, N. M. Johnson, J. Walker, D. P. Bour, and R. A. Street, “Activation of acceptors in Mg-doped GaN grown by metalorganic chemical vapor deposition,” Appl. Phys. Lett. 68, 667–669 (1996).
[CrossRef]

Weimar, A.

A. Weimar, A. Lell, G. Brüderl, S. Bader, and V. Härle, “Investigation of low-resistance metal contacts on p-type GaN using the linear and circular transmission line method,” Phys. Stat. Sol. (a) 183, 169–175 (2001).
[CrossRef]

Wetzel, C.

I. Akasaki and C. Wetzel, “Future challenges and directions for nitride materials and light emitters,” Proc. IEEE 85, 1750–1751 (1997).
[CrossRef]

Wuu, D.-S.

R.-H. Horng, D.-S. Wuu, Y.-C. Lien, and W.-H. Lan, “Low-resistance and high-transparency Ni/indium tin oxide ohmic contacts to p-type GaN,” Appl. Phys. Lett. 79, 2925–2927 (2001).
[CrossRef]

Yamasaki, S.

Y. Koide, H. Ishikawa, S. Kobayashi, S. Yamasaki, S. Nagai, J. Umezaki, M. Koike, and M. Murakami, “Dependence of electrical properties on work functions of metals contacting to p-type GaN,” Appl. Surf. Sci. 117/118, 373–379 (1997).
[CrossRef]

Yeh, R.-C.

S.-M. Pan, R.-C. Tu, Y.-M. Fan, R.-C. Yeh, and J.-T. Hsu, “Enhanced output power of InGaN-GaN light-emitting diodes with high-transparency nickel-oxide-indium-tin-oxide ohmic contacts,” IEEE Photon. Technol. Lett. 15, 646–648 (2003).

Yeom, G. Y.

D. W. Kim, Y. J. Sung, J. W. Park, and G. Y. Yeom, “A study of transparent indium tin oxide (ITO) contact to p-GaN,” Thin Solid Films 398/399, 87–92 (2001).
[CrossRef]

D. W. Kim, Y. J. Sung, J. W. Park, and G. Y. Yeom, “A study of transparent indium tin oxide (ITO) contact to p-GaN,” Thin Solid Films 398/399, 87–92 (2001).
[CrossRef]

Yoon, S. K.

S. W. Chae, K. C. Kim, D. H. Kim, T. G. Kim, S. K. Yoon, B. W. Oh, D. S. Kim, H. K. Kim, and Y. M. Sung, “Highly transparent and low-resistant ZnNi/indium tin oxide ohmic contact on p-type GaN,” Appl. Phys. Lett. 90, 181101 (2007).
[CrossRef]

Appl. Phys. Express (1)

Y. Kuwahara, T. Fujii, T. Sugiyama, D. Iida, Y. Isobe, Y. Fujiyama, Y. Morita, M. Iwaya, T. Takeuchi, S. Kamiyama, I. Akasaki, and H. Amano, “GaInN-based solar cells using strained-layer GaInN/GaInN superlattice active layer on a freestanding GaN substrate,” Appl. Phys. Express 4, 021001(2011).
[CrossRef]

Appl. Phys. Lett. (7)

W. Götz, N. M. Johnson, J. Walker, D. P. Bour, and R. A. Street, “Activation of acceptors in Mg-doped GaN grown by metalorganic chemical vapor deposition,” Appl. Phys. Lett. 68, 667–669 (1996).
[CrossRef]

J. K. Sheu, Y. K. Su, G. C. Chi, P. L. Koh, M. J. Jou, C. M. Chang, C. C. Liu, and W. C. Hung, “High-transparency Ni/Au ohmic contact to p-type GaN,” Appl. Phys. Lett. 74, 2340–2342 (1999).
[CrossRef]

T. Margalith, O. Buchinsky, D. A. Cohen, A. C. Abare, M. Hansen, S. P. DenBaars, and L. A. Coldren, “Indium tin oxide contacts to gallium nitride optoelectronic devices,” Appl. Phys. Lett. 74, 3930–3932 (1999).
[CrossRef]

J. O. Song, D. S. Leem, J. S. Kwak, O. H. Nam, Y. Park, and T. Y. Seong, “Low-resistance and highly-reflective Zn–Ni solid solution/Ag ohmic contacts for flip-chip light-emitting diodes,” Appl. Phys. Lett. 83, 4990–4992 (2003).
[CrossRef]

T. Margalith, O. Buchinsky, D. A. Cohen, A. C. Abare, M. Hansen, S. P. DenBaars, and L. A. Coldren, “Indium tin oxide contacts to gallium nitride optoelectronic devices,” Appl. Phys. Lett. 74, 3930–3932 (1999).
[CrossRef]

R.-H. Horng, D.-S. Wuu, Y.-C. Lien, and W.-H. Lan, “Low-resistance and high-transparency Ni/indium tin oxide ohmic contacts to p-type GaN,” Appl. Phys. Lett. 79, 2925–2927 (2001).
[CrossRef]

S. W. Chae, K. C. Kim, D. H. Kim, T. G. Kim, S. K. Yoon, B. W. Oh, D. S. Kim, H. K. Kim, and Y. M. Sung, “Highly transparent and low-resistant ZnNi/indium tin oxide ohmic contact on p-type GaN,” Appl. Phys. Lett. 90, 181101 (2007).
[CrossRef]

Appl. Surf. Sci. (1)

Y. Koide, H. Ishikawa, S. Kobayashi, S. Yamasaki, S. Nagai, J. Umezaki, M. Koike, and M. Murakami, “Dependence of electrical properties on work functions of metals contacting to p-type GaN,” Appl. Surf. Sci. 117/118, 373–379 (1997).
[CrossRef]

Electron. Mater. Lett. (1)

A. Mao, J. Cho, E. F. Schubert, J. K. Son, C. Sone, W. J. Ha, S. Hwang, and J. K. Kim, “Reduction of efficiency droop in GaInN/GaN light-emitting diodes with thick AlGaN cladding layers,” Electron. Mater. Lett. 8, 1–4 (2012).
[CrossRef]

IEEE Photon. Technol. Lett. (2)

J.-O. Song, D.-S. Leem, J. S. Kwak, Y. Park, S. W. Chae, and T.-Y. Seong, “Improvement of the luminous intensity of light-emitting diodes by using highly transparent Ag-indium tin oxide p-type ohmic contacts,” IEEE Photon. Technol. Lett. 17, 291–293 (2005).
[CrossRef]

S.-M. Pan, R.-C. Tu, Y.-M. Fan, R.-C. Yeh, and J.-T. Hsu, “Enhanced output power of InGaN-GaN light-emitting diodes with high-transparency nickel-oxide-indium-tin-oxide ohmic contacts,” IEEE Photon. Technol. Lett. 15, 646–648 (2003).

J. Appl. Phys. (2)

I. Hambergend and C. G. Granquist, “Evaporated Sn-doped In2O3 films: Basic optical properties and applications to energy-efficient windows,” J. Appl. Phys. 60, R123–R160 (1986).
[CrossRef]

J. K. Ho, C. S. Jong, C. C. Chiu, C. N. Huang, K. K. Shih, L. C. Chen, F. R. Chen, and J. J. Kai, “Low-resistance ohmic contacts to p-type GaN achieved by the oxidation of Ni/Au films,” J. Appl. Phys. 86, 4491–4497 (1999).
[CrossRef]

J. Electron. Mater. (1)

Deepak and H. Krishna, “Measurement of small specific contact resistance of metals with resistive semiconductors,” J. Electron. Mater. 36, 598–605 (2007).
[CrossRef]

Jpn. J. Appl. Phys. (2)

S. Nakamura, M. Senoh, and T. Mukai, “Highly p-typed Mg-doped GaN films grown with GaN buffer layers,” Jpn. J. Appl. Phys. 30, L1708 (1991).
[CrossRef]

I. Akasaki and H. Amano, “Crystal growth and conductivity control of group III nitride semiconductors and their application to short wavelength light emitters,” Jpn. J. Appl. Phys. 36, 5393–5408 (1997).
[CrossRef]

Phys. Stat. Sol. (a) (1)

A. Weimar, A. Lell, G. Brüderl, S. Bader, and V. Härle, “Investigation of low-resistance metal contacts on p-type GaN using the linear and circular transmission line method,” Phys. Stat. Sol. (a) 183, 169–175 (2001).
[CrossRef]

Phys. Status Solidi A (1)

J. Szczyrbowski, A. Dietrich, and H. Hoffmann, “Optical and electrical properties of RF-sputtered indium–tin oxide films,” Phys. Status Solidi A 78, 243–252 (1983).
[CrossRef]

Proc. IEEE (1)

I. Akasaki and C. Wetzel, “Future challenges and directions for nitride materials and light emitters,” Proc. IEEE 85, 1750–1751 (1997).
[CrossRef]

Semicond. Sci. Technol. (2)

J. W. Orton, “Acceptor binding energy in GaN and related alloys,” Semicond. Sci. Technol. 10, 101–104 (1995).
[CrossRef]

L. Lewis, P. P. Maaskant, and B. Corbett, “On the specific contact resistance of metal contacts to p-type GaN,” Semicond. Sci. Technol. 21, 1738–1742 (2006).
[CrossRef]

Solid-State Electron. (2)

H. H. Berger, “Models for contacts to planar devices,” Solid-State Electron. 15, 145–158 (1972).
[CrossRef]

Y. C. Lin, S. J. Chang, Y. K. Su, T. Y. Tsai, C. S. Chang, S. C. Shei, C. W. Kuo, and S. C. Chen, “InGaN/GaN light emitting diodes with Ni/Au, Ni/ITO and ITO p-type contacts,” Solid-State Electron. 47, 849–853 (2003).
[CrossRef]

Thin Solid Films (4)

D. W. Kim, Y. J. Sung, J. W. Park, and G. Y. Yeom, “A study of transparent indium tin oxide (ITO) contact to p-GaN,” Thin Solid Films 398/399, 87–92 (2001).
[CrossRef]

M. J. Alam and D. C. Cameron, “Optical and electrical properties of transparent conductive ITO thin films deposited by sol–gel process,” Thin Solid Films 377/378, 455–459 (2000).
[CrossRef]

S. Boycheva, A. K. Sytchkovab, and A. Piegari, “Optical and electrical characterization of r.f. sputtered ITO films developed as art protection coatings,” Thin Solid Films 515, 8474–8478 (2007).
[CrossRef]

D. W. Kim, Y. J. Sung, J. W. Park, and G. Y. Yeom, “A study of transparent indium tin oxide (ITO) contact to p-GaN,” Thin Solid Films 398/399, 87–92 (2001).
[CrossRef]

Other (1)

As determined by spectroscopic ellipsometry on a 67 nm ITO layer on Si.

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (4)

Fig. 1.
Fig. 1.

Current-voltage characteristics of different contact schemes on p-GaN.

Fig. 2.
Fig. 2.

Transmittance of contact films on 0.2 mm glass slides for various film stacks.

Fig. 3.
Fig. 3.

Transmittance of contact films on 0.2 mm glass slides for ITO film with and without a thin Ni or Ag layer.

Fig. 4.
Fig. 4.

Relative transmittance of ITO (67 nm), Ni/ITO (3nm/67nm), Ag/ITO (3nm/67nm) on GaN and glass.

Equations (1)

Equations on this page are rendered with MathJax. Learn more.

d=(m12)λ2nITO,

Metrics