The effect of a thin antimony layer addition on PdZn ohmic contacts for p-type InP

Abstract

The effects of addition of thin Sb layers to PdZn ohmic contacts for p-type InP were investigated. The Sb layers reduced significantly the contact resistivity of the PdZn contacts, and provided excellent reproducibility and a wide annealing temperature range to produce low resistances. The minimum contact resistivity of 7×10 −5 Ω cm 2 was obtained for the Sb (3 nm)/Zn (20 nm)/Pd (20 nm) contacts, annealed at temperature ranging from 375°C to 400°C for 2 min, where a slash (/) sign indicates the deposition sequence. Since this annealing temperature is close to that used for preparation of typical AuGeNi ohmic contacts to n-InP, simultaneous annealing for p- and n-InP ohmic contacts can be achieved by using the Sb/Zn/Pd and AuGeNi ohmic contacts for p- and n-InP, respectively.