Stress-induced leakage currents in thin Ta/sub 2/O/sub 5/ films

Abstract

Stress-induced leakage currents in thin Ta/sub 2/O/sub 5/ films were investigated after short term (6 s) and long term (2720 s) constant current stress at both gate polarities for different levels of injected current. Leakage currents were increasing and decreasing depending of the amount of injected charge, i.e. whether the U-t curve was at first, second or third stage of evaluation. The conduction mechanism was also investigated and the conclusion is that conductivity obeys Poole-Frenkel mechanism for fresh structures and modified Poole-Frenkel for stressed ones.