N-type doping of BaSi2 epitaxial films by phosphorus ion implantation and thermal annealing

Phosphorus doping by P implantation and thermal annealing of the BaSi2 epitaxial film grown on the Si(111) substrate has been studied. Raman spectroscopy results show that the structural damage due to P implantation can be almost removed by annealing within 30 and 1 s at 500 and 700 °C, respectively. The depth profile of P is investigated by secondary ion mass spectroscopy, which reveals considerably slower diffusion kinetics of P at 500 °C than 700 °C. The activation energy of the diffusion is roughly estimated to be 2 eV from the temperature dependence. The Hall measurement of the P-doped films clarifies that the P impurity is an electron donor in BaSi2. The average electron density up to the order of 1018 cm− 3 is observed.