Charge motion in silicon MOS structures

The thermally stimulated current method was applied to MOS capacitors to verify the motion of hydrogen well separated from alkaline species in the Al/SiO 2/Si system. The current peak at around 260 K in both wet and dry untreated oxide was significantly increased by the effect of water vapour, while vacuum heat treatment and treatment with diethyl ether vapour diminished it. The charge motion is characterized by an activation energy of 0.35±0.06 eV, which increased to 0.45±0.06 eV after 3.5 h of vacuum heat treatment at 420 K. A possible explanation of this rise is given.