Dielectric constant of ultrathin SiO2 film estimated from the Auger parameter -: art. no. 195313

The dielectric constant epsilon of ultrathin (0.55-7.96 nm) SiO2 films formed on a Si(001) substrate was characterized in terms of the modified Auger parameter of Si atoms, alpha(Si)('). The alpha(Si)(') was found to be as much as 0.7 eV higher for an ultrathin (0.68 nm) SiO2 film than for thick SiO2 films. From the observed oxide thickness dependence of alpha(Si)('), the epsilon of ultrathin SiO2 films was estimated by calculating the change in the polarization energy and the change in the electrostatic screening energy originating from dielectric discontinuity at the SiO2/Si interface. The epsilon of ultrathin (0.68-2.13 nm) SiO2 films was identical to that of bulk SiO2 within +/-1%.