Electron-trapping characteristics of W in SiO2

Abstract

The electron‐trapping characteristics of W in SiO₂ have been studied using evaporated and ion‐implanted W. The evaporated W results indicate a trapping cross section varying from 1.56×10⁻¹⁴ to 4.62×10⁻¹⁴ cm² depending on the evaporation time. The cross section of the implanted W is 1.06×10⁻¹⁵ cm². Thermal‐detrapping measurements indicate an activation energy of 0.9 eV, whereas optical detrapping is not observed for light energies up to 6 eV. It is not understood why there is this large discrepancy of results. It is also interesting to note that Powell and Beairsto measured a barrier height of 3.6 eV for the W‐SiO₂ interface.