Deep levels of vanadium and vanadium-hydrogen complex in silicon

Abstract

Deep levels in vanadium-doped n- and p-type silicon have been investigated using deep level transient spectroscopy (DLTS) and concentration profile measurements. The DLTS measurement reveals two electron traps of EC−0.20 eV and EC−0.45 eV, and a hole trap of EV+0.34 eV. These three levels correspond to the transitions between four charge states of interstitial vanadium. Furthermore, an electron trap of EC−0.49 eV is observed near the surface region of n-type samples etched with an acid mixture containing HF and HNO3. The origin of the trap has precisely been investigated by isochronal anneals and various chemical treatments. From these investigations, it is found that the trap is due to a complex of interstitial vanadium with hydrogen introduced by chemical etching.