摘要
Ohmic contact formation on p -type Mg-doped CuCr O2 layers grown by pulsed-laser deposition was investigated. While the current-voltage characteristics from TiAu contacts showed back-to-back Schottky behavior, a specific contact resistance of ∼1× 10-4 Ω cm2 was achieved by using Ni instead of Ti. The contact resistivity was fairly independent of measurement temperature, suggesting that tunneling is the dominant transport mechanism. The contact resistance remained practically constant upon annealing in the 100-400 °C range. Above 500 °C, the morphology became rough and the contact showed rectifying behavior. This degradation resulted from both the out-diffusion of oxygen and the in-diffusion of Ni and Au in CuCr O2. © 2007 American Institute of Physics.