Deep levels in homoepitaxial boron‐doped diamond films studied by capacitance and current transient spectroscopies

Deep level transient spectroscopies (DLTS) applied to Schottky junctions made on homoepitaxial boron‐doped diamond films show the existence of two traps. A deep acceptor, negatively charged and strongly attractive for holes, 1.57 eV above the valence band edge displays the characteristic features of a complex defect due to interacting centers and impurities, also displaying some evolutions after thermal cycles, possibly due to hydrogen effusion or diffusion. It is tentatively ascribed to association of a boron atom, a vacancy and several hydrogen atoms. A deep donor, 1.13 eV above the valence band edge, able to compensate the boron acceptors, is attributed to a defect correlated with dislocations. It could be due to the positively charged carbon vacancy. These conclusions are drawn from the Fourier transform‐DLTS results coupled with isothermal time domain algorithms allowing the discrimination of multiple emission rates with high resolution. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)