Rf-sputtered Crb_2 Diffusion Barrier For Ni/au Ohmic Contacts On P - Cucro_2

摘要

Ohmic contacts to p-type CuCrO_2 using Ni/Au/CrB_2/Ti/Au contact metallurgy are reported. The samples were annealed in the 200-700 ℃ range for 60 s in flowing oxygen ambient. A minimum specific contact resistance of ～2 × 10~(-5) Ω cm~2 was obtained after annealing at 400 ℃. Further increase in the annealing temperature (>400 ℃) resulted in the degradation of contact resistance. Auger Electron Spectroscopy (AES) depth profiling showed that out-diffusion of Ti to the surface of the contact stacks was evident by 400 ℃, followed by Cr at higher temperature. The CrB_2 diffusion barrier decreases the specific contact resistance by almost two orders of magnitude relative to Ni/Au alone.