Low voltage substrate current: a monitor for interface states generation in ultra-thin oxide n-MOSFETs under constant voltage stresses
The low voltage substrate current (Ib) has been studied based on generation kinetics and used as a monitor of interface states (Nit) generation for ultra-thin oxide n-MOSFETs under constant voltage stress. It is found that the low voltage Ib is formed by electrons tunnelling through interface states, and the variations of Ib(∆Ib) are proportional to variations of Nit (∆Nit). The Nit energy distributions were determined by differentiating Nit(Vg). The results have been compared with that measured by using gate diode technique.