TRAPPING OF ATOMIC-HYDROGEN IN SILICON BY DISORDERED REGIONS

This paper addresses issues related to migration and acceptor neutralization of hydrogen (H) in crystalline Si. From spreading resistance measurements, it is shown that disordered regions, both surface and subsurface, directly inhibit the penetration of H. Further, these effects are shown to be independent of the kind of disorder and the method of hydrogenation. Secondary-ion mass spectrometry profiles of deuterated samples confirm the suppression of deuterium movement through the disordered regions. We observe that annealing of these hydrogenated damage regions results in generation of an acceptor deactivation profile which is persistent for temperatures up to 800-degrees-C and durations up to 1 min. This sustained deactivation phenomenon results in up to four decade change in free-carrier concentration. Our results unequivocally suggests that H-soaked damage region acts as a source of atomic hydrogen under rapid thermal annealing.