ON THE POSITIVE CHARGE AND INTERFACE STATES IN METAL-OXIDE-SEMICONDUCTOR CAPACITORS

We have studied the defects created in p-metal-oxide-semiconductor cap acitors by Fowler-Nordheim injection. This injection has been performe d either from the gate or from the substrate. We have shown that the o xide keeps no memory of the trapped holes created by an injection from the gate, once they have been neutralized. Nevertheless, we think tha t the corresponding traps are stress created by a mechanism similar to that which creates the slow states. The trapped hole annihilation has no influence on the number of interface states or slow states present after stress in the oxide. The increase of the interface state densit y with injected charge depends on whether the injection is from the ga te or from the substrate. In both cases, the increase of the interface density differs from that of the trapped holes and slow states which suggests that the formation mechanisms of trapped holes and slow state s are not the same as those of interface states. (C) 1996 American Ins titute of Physics.