The temperature dependence of the contact resistivity of the Si/Ni(Mg) nonspiking contact scheme on p‐GaAs

The temperature dependence of the contact resistivity of the Si/Ni(Mg) nonspiking contact scheme on p‐GaAs has been investigated. This contact scheme has been shown to form planar contact interfaces with contact resistivities less than 1 × 10−6 Ω cm2. This investigation demonstrates that the contact resistivity can be modeled by a sum of two components in series: (i) a contact resistivity due to the metal‐GaAs interface and (ii) a contact resistivity due to the high‐low junction formed between the highly doped regrown GaAs layer and the substrate. For degenerately doped samples (4.5 × 1019 cm−3), the contact resistivity is nearly independent of the temperature from 300 to about 30 K, indicating that the dominant resistivity is that across the metal‐semiconductor tunneling barrier. For samples with lower doping concentrations (≤ 1.5 × 1018 cm−3), the contact resistivity increases with decreasing temperature, suggesting the dominance of the contact resistivity due to the high‐low junction.