Vv. Afanasev et al., DEGRADATION OF THE THERMAL OXIDE OF THE SI SIO2AL SYSTEM DUE TO VACUUM-ULTRAVIOLET IRRADIATION/, Journal of applied physics, 78(11), 1995, pp. 6481-6490
The generation of point defects in Si/SiO2/Al capacitors due to exposu
re to vacuum ultraviolet (VUV) (10 eV) radiation has been investigated
by studying the electron and hole trapping properties and electron-sp
in-resonance spectroscopy for exposures ranging from 10(14) up to 10(1
9) photons cm(-2) absorbed in the oxide. At low VUV exposures, the gen
eration of hydroxyl groups and electron traps with cross section great
er than or equal to 10(-16) cm(2) is observed; however, for exposures
larger than 10(17) cm(-2) these centers are subsequently eliminated. F
or exposures larger than 10(18) cm(-2) the oxide network is gradually
destroyed; oxygen atoms are removed from their network positions and d
ecorated with hydrogen atoms, thus producing water molecules and triva
lent silicon centers in comparable numbers. At an exposure of 10(19) c
m(-2), of the order of 10(14) cm(-2) of oxygen atoms are removed, with
out any indication that the process would saturate. A tentative model
is presented in which the degeneration process takes place at regular
network sites; a defect precursor is not invoked. It is proposed that
neutralization of self-trapped hydrogen/hole pairs at the oxygen atoms
plays a crucial role in this process. (C) 1995 American Institute of
Physics.