Forming process of unipolar resistance switching in Ta2O5−x thin films

We investigated the film-thickness and ambient oxygen-pressure dependence of the electric field, EF, required to initiate unipolar resistance switching (URS) in Ta2O5−x thin films. We measured the dependence of EF by applying a triangular-waveform voltage signal to the film over a wide sweep-rate range (v = 20 mV s−1 to 5 MV s−1). Our results showed that the URS-EF was not influenced by the Ta2O5−x film thickness nor ambient oxygen-pressure. This suggested that the URS-forming process in Ta2O5−x thin films should be governed by thermally assisted dielectric breakdown in our measurement range.