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

Abstract

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 transfonn-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.