Gate-oxide grown on the sidewalls and base of a U-shaped Si trench: effects of the oxide and oxide/Si interface condition on the properties of vertical MOS devices
We report on the SiO2/Si interface condition and on its high electric field stress reliability in U-shaped trench gated metal-oxide-silicon (MOS) structures. The interface state density measured is ?1011 eV?1 cm?2, and using deep level transient spectroscopy the Pb center is found to be the dominant interface defect. The degradation induced by electrical stressing is examined using changes in the charge pumping current in a U-trench-gated transistor. It is shown that the SiO2/Si interface at the bottom corners of the trench is the weakest region in the MOS structure.
interface states charge pumping umosfet mos capacitor gate oxide oxide/silicon interface rie etching cv dlts p-center oxide charge