Interface state generation mechanism in n-MOSFET's

Abstract

Uniform carrier injection into the channel of n-MOSFETs generates two types of interface states, depending on the oxide electric field: One is linearly proportional to the injected electron density (Type I), while the other shows a half-power dependence (Type II). Charge-pumping measurements in the temperature range of 77K and 263K show that the type I interface states are located in the mid-gap, while the type II interface states are uniformly distributed in wide energy range. Holes generated at the gate/SiO 2 interface or in the oxide are found to be responsible for the type I interface states, while hydrogen or hydrogen compounds diffusing from the interface cause the type II interface states.