Direct observation of the threshold for electron heating in silicon dioxide

Vacuum-emission and carrier-separation techniques, together with novel metal-oxide-semiconductor structures, have been used to observe the threshold field for the onset of electron heating in silicon dioxide. The magnitude of this electric field is 1.5-2.0 MV/cm, independent of oxide thickness and composition. This value is consistent with all of the current theoretical calculations. A minimum average electronic energy of 1.0 eV is shown to be necessary to observe emission of the electrons into vacuum. © 1986 The American Physical Society.