Temperature dependence of the contact resistance of ohmic contacts to III–V compounds with a high dislocation density

A new mechanism describing the rise in the contact resistance $\rho_c$ of ohmic contacts to $n$–$n^+$–$n^{++}$-GaAs (GaP, GaN, InP) structures with increasing measurement temperature $T$, experimentally observed in the temperature range 100–400 K, is suggested on the basis of a theoretical analysis of the temperature dependence of $\rho_c$. Good agreement between the experimental and theoretical $\rho_c(T)$ dependences is obtained and explained for a case where there is a high density of dislocations (on which metallic shunts are localized) in the near-contact region of the semiconductor.