Engineering of Hf1−xAlxOy amorphous dielectrics for high-performance RRAM applications

We propose for the first time a systematic evaluation of the performance and underlying trade-off of the use of ternary Hf
_1-x
Al
_x
O
_y
oxides for RRAM application. We show that intermixing HfO
₂
and Al
₂
O
₃
deposition cycles in a standard ALD process not only prevents crystallization of active layer but also significantly improve intrinsic retention and disturb-immunity properties at the expense of a small increase of programming voltage. We attribute this beneficial effect to the reduced V
_o
diffusivity caused by stronger Al-O bonds as suggested by ab-initio simulations.