This study investigates electrical characteristics and the formation mechanism of the Cu/Ge/Pd Ohmic contact to n-type InGaAs. After annealing the contact at 250°C for 20 min, Cu 3Ge and Pd 12Ga 5As 2 compounds formed and Ge diffused into the InGaAs layer, achieving a heavily doped InGaAs layer with a low contact resistivity of 1 × 10 -6 Ω cm 2. Thermal stability tests were performed on the Cu/Ge/Pd Ohmic contact to InGaAs after Ohmic contact formation, showing no obvious degradation after a 72 h reliability test at 250°C. The results indicate excellent electrical characteristics and thermal stability using Cu/Ge/Pd as an Ohmic contact metal to an n-InGaAs layer.
- Copper metalization
- Cu/Ge/Pd Ohmic contact