Measurements of deep penetration of low-energy electrons into metal-oxide-semiconductor structure

Abstract

A polycrystalline Si‐SiO₂‐Si metal‐oxide‐semiconductor (MOS) transistor covered with thick insulation and passivation layers of SiO₂ was examined to measure the threshold voltage shifts as a function of electron energy over the range of from 5 to 18 keV. The electron‐beam fluence was varied over six orders of magnitude from 2×10⁻⁹ to 2×10⁻³ C/cm². From the experimental data, the fraction of the incident electron energy deposited in the gate oxide was determined. The result shows a deep penetration of low‐energy electrons beyond the electron range.