title: Evaluation of metal/indium-tin-oxide for transparent low-resistance contacts to p-type GaN.
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 (3 nm/67 nm) ohmic contact with a relative transmittance of 97% of the bare GaN near 530 nm and a specific contact resistance of 0.03 Ω·cm2. The contact proves suitable for green light-emitting diodes in epi-up geometry.
authors.affiliation: Future Chips Constellation and Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.
authors.forename: Wenting
authors.initials: W
authors.lastname: Hou
authors.forename: Christoph
authors.initials: C
authors.lastname: Stark
authors.forename: Shi
authors.initials: S
authors.lastname: You
authors.forename: Liang
authors.initials: L
authors.lastname: Zhao
authors.forename: Theeradetch
authors.initials: T
authors.lastname: Detchprohm
authors.forename: Christian
authors.initials: C
authors.lastname: Wetzel