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 investigated by magnetic resonance. Hydrogen was introduced by heat treatment at high temperatures in an atmosphere of water vapor. Two spectra were observed, labeled Si-NL60 and Si-NL61 for further reference, both showing trigonal symmetry for the paramagnetic center. By using isotopically enriched selenium and heavy (deuterated) water, the participation of selenium and hydrogen in the structure of the centers was conclusively established. By analysis of the experimental data, microscopic models for the centers were developed. It is concluded that spectrum Si-NL60 corresponds to a SeH pair in a neutral charge state. An unambiguous interpretation of the Si-NL61 spectrum cannot yet be presented. According to the spectroscopic information from the experiment, Si-NL61 is the spectrum of a selenium center with two hydrogen atoms on nonequivalent sites, which is observed in an ionized state. Alternatively, 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. ©2000 The American Physical Society.