The temperature dependence of the resistivity of ohmic contacts based on gallium arsenide and indium phosphide in the 4.2–300 K range

Resumo

Resistivity ρ_c of InP- and GaAs-based ohmic contacts has been measured in a temperature range of 4.2–300 K. Both temperature dependences are nonmonotonic and exhibit minima at T = 50 K for InP and T = 150 K for GaAs. The nonmonotonic ρ_c(T) curves for GaAs contacts have been observed for the first time. The obtained experimental temperature dependences of ρ_c can be explained in the framework of the mechanism of current passage via metal shunts incorporated into semiconductor with allowance for electrons freezing out at liquid-helium temperatures. The ohmic character of contacts is ensured due to limitation of the electron current by diffusion supply in the presence of band bending at the semiconductor–metal interface near the shunt edge.