TY - JOUR
T1 - Graphene diffusion barrier for forming ohmic contact on N-polar n-type GaN for high-power vertical-geometry light-emitting diodes
AU - Kim, Dae Hyun
AU - Park, Jae Seong
AU - Seong, Tae Yeon
PY - 2014/1/1
Y1 - 2014/1/1
N2 - Graphene sheets were employed as a diffusion barrier to form highly reliable ohmic contacts to N-polar n-GaN for high-power vertical-configuration LEDs (VLEDs). Before annealing, both Ti/Al and Ti/graphene/Al contacts exhibit ohmic behavior. After annealing at 250 °C, unlike the Ti/Al contact, the Ti/graphene/Al contacts remain ohmic with a contact resistivity of 7.5 × 10-4Ωcm2. Secondary ion mass spectroscopy (SIMS) results show that the graphene sheets serve as a barrier to the outdiffusion of Ga atoms into the electrode. On the basis of SIMS and X-ray photoemission spectroscopy results, the ohmic and degradation behaviors of the Ti-based contacts are described and discussed.
AB - Graphene sheets were employed as a diffusion barrier to form highly reliable ohmic contacts to N-polar n-GaN for high-power vertical-configuration LEDs (VLEDs). Before annealing, both Ti/Al and Ti/graphene/Al contacts exhibit ohmic behavior. After annealing at 250 °C, unlike the Ti/Al contact, the Ti/graphene/Al contacts remain ohmic with a contact resistivity of 7.5 × 10-4Ωcm2. Secondary ion mass spectroscopy (SIMS) results show that the graphene sheets serve as a barrier to the outdiffusion of Ga atoms into the electrode. On the basis of SIMS and X-ray photoemission spectroscopy results, the ohmic and degradation behaviors of the Ti-based contacts are described and discussed.
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U2 - 10.7567/APEX.7.046501
DO - 10.7567/APEX.7.046501
M3 - Article
AN - SCOPUS:84904624732
VL - 7
JO - Applied Physics Express
JF - Applied Physics Express
SN - 1882-0778
IS - 4
M1 - 046501
ER -