Thermally stimulated properties of CVD diamond films

Thermally stimulated luminescence (TL), current (TSC) and exoelectronic emi ssion (TSEE) of different CVD diamond films grown on silicon substrates hav e been studied in order to obtain information on defects created during the growth and which induce levels within the gap. TL and TSC have been perfor med between 100 and 600 K, whereas TSEE has been measured from 300 to 700 K . Several TL peaks located between 275 and 540 K are observed, with differe nt relative intensities depending on the samples. A single TL peak located at about 515-540 K is associated with a trap level 0.8 eV deep. This level gives rise to TSC, whereas the peak located at 275 K, and which may be attr ibuted to the presence of boron, does not give a TSC signal. A TSEE peak lo cated at 595 K is measured for all the samples but cannot be correlated wit h TL and TSC peaks. This is probably due to the presence of defects that ar e present only near the surface of the films. (C) 2000 Elsevier Science S.A . All rights reserved.