Materials science and engineering b-solid state materials for advanced technology vol:58 issue:1-2 pages:71-75
The process of interface degradation induced in (111)Si/SiO2 by postoxidation annealing (POA) in vacuum, previously identified by electron spin resonance (ESR) as creation of persistent P-b, (Si/Si-3) interface defects, is found to be strongly enhanced (approximate to 6 times) when performed in H-2 ambient, and additionally, as sensed by ESR, the treshold temperature for creation is lowered from approximate to 640 degrees C for vacuum to approximate to 550 degrees C. It thus appears that POA in H-2 rich ambient, such as routinely applied to passivate interface states (preexisting P(b)s) naturally introduced during oxidation, effectively creates extra defect entities, which then have to be passivated additionally. The results point to the key role of the POA ambient in interface degradation. The data reveal the atomic nature of one of the mechanisms of the electrically long known H-induced POA generation of detrimental interface states. (C) 1999 Elsevier Science S.A. All rights reserved.