Unsteady silicon nitride conductivity in high electric fields

Unsteady currents are experimentally investigated in silicon nitride. The experiments made to separate the direct current from the capturing current show that the unsteady current at t > 3 s is a direct current. The carrier injection from the silicon-insulator is found to be affected by a tunnelling mechanism. Separation of the electron and hole components of the unsteady current shows that the current flowing near the silicon-insulator interface in a tunnelling thin oxide structure is transported by the carriers injected from silicon to the insulator. The current of the charges from the insulator to silicon is rather low. The high electric fields possess some unsteadiness displaying the current rise with time. The current rise is a accompanied by appropriate field increase at the silicon-insulator interface resulting in the breakdown of the MNOS-structure. (author)