Hot-carrier stress damage in the gate `off´ state in n-channel transistors

Hot-carrier damage in the `of´ state (V_g⩽ V_t while V_d is high, V _g(off)) in silicon n-MOS transistors is examined. This condition commonly occurs due to capacitively coupled noise at the input of a CMOS inverter. It is shown that damage can occur under these conditions in the form of oxide trapped charge. Contrary to interface state creation, V_g(off) damage increases with increasing temperature, resulting in this type of damage dominating over interface state creation at high temperatures. It is concluded that care must be taken to ensure that the gate voltage at the input of an inverterlike circuit stays well below the threshold voltage when the output is high