Self-Limited and Forming-Free CBRAM Device With Double Al 2 O 3 ALD Layers

Self-limited and forming-free Cu-based CBRAM devices with a double Al 2 O 3 atomic layer deposition layer (D-ALD) structure were developed. The proposed structure offers desirable properties such as forming free ( ${V}_{\textsf {forming}}={V}_{\textsf {SET}}$ ), self-limited resistive switching with very low programming current ~10 nA), high ON/ OFF ratio (> 100), and nonlinear ${I}$ – ${V}$ (NL $_{\textsf {read}}$ and NL $_{\textsf {SET}}$ ~ 10) at low resistance state. The outstanding performance of D-ALD devices was due to the HT-ALD layer that operates as both a diffusion barrier preventing over injection of Cu ions and a tunneling barrier enabling self-limited programming.