New hot carrier failure criterion for p-channel transistors based on transistor leakage currents

Abstract

Although hot carrier failure in very short channel (<0.35 μm) p-MOS transistors is often described in terms of threshold voltage ( V t) shifts, a more meaningful hot carrier indicator for dynamic logic is the leakage current, I d.off (measured at V d = −3.6V, V g = −0.1V). A new method for determining the hot carrier failure time based on the leakage current is proposed here. This method has the advantage of being independent of the initial threshold voltage. A relationship is proposed that links the leakage current to the effective length of the transistor. With this relationship, it is possible to quickly screen for whether devices meet the hot carrier criterion, by simply measuring the leakage current and the effective channel length.