Lattice location of phosphorus in n-type homoepitaxial diamond films grown by chemical-vapor deposition

The lattice location of phosphorus dopant atoms in n-type homoepitaxial diamond {111} films grown by chemical-vapor deposition has been investigated by Rutherford backscattering spectrometry and particle-induced x-ray emission under ion-channeling conditions. It is found that phosphorus dopant atoms occupy the substitutional sites almost completely in the host diamond lattice. The substitutional fraction of phosphorus was more than 0.9 for 〈011〉 and 〈111〉 directions. Present observation implies that the deep ground-state energy level of phosphorus in diamond, which is at 0.6 eV below the bottom of the conduction band, is attributed to the relaxation of surrounding carbon atoms.