Increased Deep-Level Hole Trapping by Combined Negative-Bias Temperature and Channel Hot-Hole Stress

Trapping of holes at deep energy states under negative-bias-temperature instability (NBTI) is examined in the presence of a nonzero drain bias [i.e., channel hot-hole (CHH) effect]. While the total density of switching hole traps is unchanged after the combined NBTI and CHH stress (implying no additional creation of such traps for the conditions studied), evidence shows that the density of deep-level switching hole traps is increased. Enhanced carrier-lattice interaction under hot-hole injection is believed to induce the greater structural relaxation inherent to specific precursor sites for these deep-level hole traps. Implications of this observation are briefly discussed.