Carrier capture at the SiO2–Si interface: A physical model

Abstract

The carrier (electron and hole) capture cross section of defects at the SiO2–Si interface is measured using trap-fill time in gigahertz charge-pumping experiment. The ability to use a highly asymmetric rectangular wave with very fast rise and fall times in our charge-pumping experiment greatly simplified data interpretation. Trap-fill times of less than or equal to 0.7ns are found for both electrons and holes. The corresponding capture cross section of 10−15cm2 or larger for both electron and hole cannot be explained by the usual multiphonon emission mechanism. A modified cascade capture model involving the strained Si–Si bonds around the Pb center is proposed to explain the large capture cross sections.