Secondary ion mass spectroscopy study of Zn or Cd implanted and rapid thermally annealed Pd/Ge contacts to p‐In0.53Ga0.47As

Backside secondary ion mass spectroscopy is used to examine elemental redistribution in Zn or Cd implanted Pd/Ge contacts to p‐InGaAs. A quaternary Pd‐In‐Ga‐As layer is observed at annealing temperatures of 200–250 °C. At temperatures ≳250 °C, this layer disappears due to PdGe formation and InGaAs regrowth. Excess Ge diffuses to the contact interface. Cd and Zn accumulate inside the regrown InGaAs creating a thin, highly doped layer. Due to its abrupt interface and the formation of a highly doped layer beneath the contact, this implanted Pd/Ge contact scheme is a promising candidate for shallow ohmic contacts to p‐InGaAs.