Electron and hole traps in SiO/sub 2/ films thermally grown on Si substrates in ultra-dry oxygen

The densities of electron and hole traps in SiO/sub 2/ films, thermally grown on Si substrates in ultra-dry oxygen, were compared with those in SiO/sub 2/ films grown in pyrogenic steam (wet-oxide films). The results show that ultra-dry-oxide films have an undetectable density of electron traps that is less that 10/sup 11//cm/sup 2/, and little interface-states generation during carrier injection. However, hole traps in ultra-dry-oxide films are high, (2.6+or-0.1)*10/sup 12//cm/sup 2/ compared with (1.3+or-0.2)*10/sup 12//cm/sup 2/ in wet-oxide films, and these increase by a factor of two with post-oxidation anneal in ultra-dry Ar. The results of electron spin resonance measurements of E' centers in SiO/sub 2/ films are consistent with the results of electrical measurements. These suggest that there is a tradeoff correlation between the density of electron traps and hole traps, with respect to the amount of water- or hydrogen-related defects in SiO/sub 2/.<
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