Electrical and optical properties of carbon- and phosphorus-implanted ultrananocrystalline diamond films

Carbon or phosphorus ions with doses 1012 cm-2 and 1014 cm-2 were implanted into ultrananocrystalline diamond (UNCD) films in order to produce low resistivity n-type diamond structures. The effects of carbon (phosphorus) ion dose and annealing at temperatures from 800 to 1000 °C on the electrical and optical properties of UNCD films have been investigated by Hall effect, Raman and Charge-based Deep Level Transient Spectroscopy (Q-DLTS) measurements. The capacitance characteristics and kinetics of the photoresponse were studied also. Q-DLTS spectra of the ion-implanted UNCD films show a continuous energy spectrum of electron traps with two peaks. The first with Eact ≈ 0.08 eV corresponds to point defects which are determine the n-type conductivity of ion-implanted UNCD films and another peak is induced by the surface absorption of predominantly hydrogen groups on the active surface of diamond