Charge state of the O-2 molecule during silicon oxidation through hybrid functional calculations

Article

关键词: AB-INITIO CALCULATIONS;    SIO2/SI INTERFACE;    LAYER;    1ST-PRINCIPLES;    DYNAMICS;    SURFACES;    KINETICS;    EXCHANGE;   

DOI  :  10.1103/PhysRevB.78.161305

来源: SCIE

【 摘 要 】

We study the charge state of the diffusing O-2 molecule during silicon oxidation through hybrid functional calculations. We calculate charge-transition levels of O-2 in bulk SiO2 and use theoretical band offsets to align these levels with respect to the Si band edges. To overcome the band-gap problem of semilocal density functionals, we employ hybrid functionals with both predefined and empirically adjusted mixing coefficients. We find that the charge-transition level epsilon(0/-) in bulk SiO2 occurs at similar to 1.1 eV above the silicon conduction-band edge, implying that the O-2 molecule diffuses through the oxide in the neutral charge state. While interfacial effects concur to lower the charge-transition level, our estimates suggest that the neutral charge state persists until silicon oxidation.

【 授权许可】

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