Kinetics of accumulation and annealing of surface states at interfaces in irradiated silicon-silicon dioxide structures

The method of recording subthreshold current-voltage characteristics yielded information on the kinetics of accumulation and annealing of surface states at the interface between silicon and silicon dioxide in transistors MOS structures after irradiation with 6-MeV electrons in doses of 5 x 1014-1017 cm-2. The distribution of the surface state density had two maxima: the first was located near Ev + 0.35 eV, whereas the second was near Ec - 0.34 eV. The dose dependences of the surface state density had a maximum near a dose of 5 x 1015 cm-2. The kinetics of isothermal annealing of the density of the surface states at 200C in air consisted of two stages: during the first 20 min there was a steep reduction in the density of the surface states and this was followed by slow decay. The time dependence of the density of these states was approximated by a sum of two exponential functions. Potential models which could account qualitatively for the observed dose dependences and kinetics were considered