FAILURE OF AL-SIO2-SI MOS CAPACITORS AT HIGH-TEMPERATURES

Failure of Al-SiO2Si MOS capacitors operated at elevated temperatures was studied. The time required for the devices to develop conducting p aths through the oxide was found to vary with oxide thickness, tempera ture, and electrical bias. A thermally activated, electric-field-assis ted Si-O bond-breaking process appears to be responsible for the oxide failure. A model is discussed in which the time to failure is express ed as an exponential function of the temperature and of the electric f ield within the silicon dioxide.