TY - JOUR
T1 - High temperature Ohmic contacts to p-type GaN for use in light emitting applications
AU - Voss, L. F.
AU - Stafford, L.
AU - Hlad, M.
AU - Gila, B. P.
AU - Abernathy, C. R.
AU - Pearton, S. J.
AU - Ren, F.
AU - Kravchenko, I.
PY - 2008
Y1 - 2008
N2 - Achieving low resistance contacts to p-type Gallium Nitride is a critical requirement for the fabrication of reliable Al-GaN/InGaN laser diodes and nitride-based light-emitting diodes (LEDs). Three separate groups of materials are examined. The first is a family of borides, including W2B, W 2B5, CrB2, TiB2, and ZrB 2; the second is a group of nitrides, TaN, TiN, and ZrN; and the third is the refractory metal Ir. Using these materials both directly on the surface of p-GaN as well as a diffusion barrier for Ni/Au-based Ohmic contacts, specific contact resistances as low as ∼1x10-4 Ω.cm 2 have been achieved. In addition, the boride and iridium based contacts display superior aging characteristics with minimal degradation of the contact resistance and of the turn on voltage of light emitting diodes after extended periods at 350°C. The reasons for the discrepancies in performance of different materials is examined through the use of IV curves as well as Auger Electron Spectroscopy (AES) depth profiles.
AB - Achieving low resistance contacts to p-type Gallium Nitride is a critical requirement for the fabrication of reliable Al-GaN/InGaN laser diodes and nitride-based light-emitting diodes (LEDs). Three separate groups of materials are examined. The first is a family of borides, including W2B, W 2B5, CrB2, TiB2, and ZrB 2; the second is a group of nitrides, TaN, TiN, and ZrN; and the third is the refractory metal Ir. Using these materials both directly on the surface of p-GaN as well as a diffusion barrier for Ni/Au-based Ohmic contacts, specific contact resistances as low as ∼1x10-4 Ω.cm 2 have been achieved. In addition, the boride and iridium based contacts display superior aging characteristics with minimal degradation of the contact resistance and of the turn on voltage of light emitting diodes after extended periods at 350°C. The reasons for the discrepancies in performance of different materials is examined through the use of IV curves as well as Auger Electron Spectroscopy (AES) depth profiles.
UR - http://www.scopus.com/inward/record.url?scp=77951240374&partnerID=8YFLogxK
U2 - 10.1002/pssc.200778644
DO - 10.1002/pssc.200778644
M3 - Conference article
AN - SCOPUS:77951240374
SN - 1862-6351
VL - 5
SP - 2241
EP - 2243
JO - Physica Status Solidi (C) Current Topics in Solid State Physics
JF - Physica Status Solidi (C) Current Topics in Solid State Physics
IS - 6
T2 - 7th International Conference of Nitride Semiconductors, ICNS-7
Y2 - 16 September 2007 through 21 September 2007
ER -