Highly reliable Pd-based ohmic contacts of p-type InP

摘要

Low resistance and highly reliable Sb/Zn/Pd Ohmic contacts to p-type InP were developed. PdZn contacts with a few nm thick Sb first layer provided excellent reproducibility and a wide annealing temperature range to produce low resistances. The minimum contact resistivity of 7×10{sup}(-5) Ωcm{sup}2 was obtained for the Sb(3 nm)/Zn(20 nm)/Pd(20 nm) contacts after annealing at temperature ranging from 375°C to 400°C for 2 mm. The diffusion depth of the contact metals into the InP substrate was less than 50 nm, which was about 10 times shallower than that of the conventional AuZn contacts.