Self-Limited and Forming-Free CBRAM Device With Double Al2O3 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.