Hydrogen passivation of the selenium double donor in silicon: A study by magnetic resonance

The passivation by hydrogen of selenium double donors in silicon has been i nvestigated by magnetic resonance. Hydrogen was introduced by heat treatmen t at high temperatures in an atmosphere of water vapor. Two spectra were ob served, labeled Si-NL60 and Si-NL61 for further reference, both showing tri gonal symmetry for the paramagnetic center. By using isotopically enriched selenium and heavy (deuterated) water, the participation of selenium and hy drogen in the structure of the centers was conclusively established. By ana lysis of the experimental data, microscopic models for the centers were dev eloped. It is concluded that spectrum Si-NL60 corresponds to a SeH pair in a neutral charge state. An unambiguous interpretation of the Si-NL61 spectr um cannot yet be presented. According to the spectroscopic information from the experiment, Si-NL61 is the spectrum of a selenium center with two hydr ogen atoms on nonequivalent sites, which is observed in an ionized state. A lternatively, it could correspond to two neutral one-selenium-one-hydrogen pairs which resemble each other so much that they are indistinguishable by electron paramagnetic resonance.