Ohmic contacts with palladium diffusion barrier on III–V semiconductors

Ohmic contacts with a palladium (Pd) diffusion barrier were formed on GaAs substrates. The metal-contact structure consists of a gold-based-alloy/Pd/semiconductor-substrate. Characteristics of the deposited Pd films by “electroless” deposition on semiconductor-substrates are reported. SIMS analysis realized on the metal-semiconductor structures demonstrates the capability of the Pd films to act as a diffusion barrier. Contact resistance of the ohmic contacts was measured by the transmission line method (TLM).