ENERGY-DISTRIBUTION OF SLOW TRAPPING STATES IN METAL-OXIDE-SEMICONDUCTOR DEVICES AFTER FOWLER-NORDHEIM INJECTION

Slow trapping charges in metal-oxide-semiconductor capacitors resultin g from Fowler-Nordheim injection are investigated by an improved stati c capacitance method which PrOvides direct experimental evidence for s low charging traps and their energy distribution. After the initial cl earing of charges directly caused by the stress condition, a significa nt amount of slow traps are left which can be charged and discharged b y alternating the gate bias. The number of trap sites is found to slig htly decrease during repeated charging and discharging. The prominent peak of slow traps is energetically located around that of conventiona l interface traps, indicating a close correlation of both types of tra ps.