Nonalloyed InGaAs/GaAs ohmic contacts for self‐aligned ion implanted GaAs heterostructure field effect transistors

Nonalloyed indium gallium arsenide (InGaAs) ohmic contacts were investigated and successfully applied to both n‐ and p‐type self‐aligned ion implanted heterostructure field effect transistors (HFETs). The key factor was to preserve the doping concentration and structure integrity of the InGaAs layer during implant activation. Specific contact resistances in the range of 5×10−6–2×10−5 Ω cm for n and p HFETs were realized with this structure and process.