Deactivation of the boron acceptor in silicon by hydrogen

Abstract

Two new experiments are presented which suggest that the ‘‘bulk-compensating donor’’ phenomenon observed in p-Si is probably a deactivation process of the boron acceptor by hydrogen with the formation of a B−H+ pair. The two experiments are (i) avalanche hole injection in Al-gate metal-oxide-silicon capacitor from boron-diffused n-Si substrate and (ii) 5-keV electron irradiation of Al/p-Si Schottky diodes. Atomic hydrogen may be released by the avalanche injected energetic electrons or holes or keV electrons from the Al–H, AlO–H, Si–H, and SiO–H sites in the Al gate and the SiO2 film as well as at the Al/SiO2 and SiO2/Si interfaces, which may then migrate to the boron acceptor sites to form the B−H+ pair. Observed hydrogen bond breaking rate by holes is as much as two orders of magnitude larger than by electrons, which is consistent with the thermal hole capture and energetic electron impact bond-breaking models.