To be compatible with 3-D vertical crossbar arrays, a TiO 2HfO2 bilayer resistive-switching memory (RRAM) cell sandwiched between Ni electrodes is developed. The proposed device has numerous highly desired features for the implementation of 3-D vertical RRAM, including: 1) stable bipolar resistive switching; 2) forming free; 3) self-compliance; 4) self-rectification; 5) multiple resistance states; and 6) room-temperature process. The resistive switching and current rectification are attributed to oxygen vacancy migration in HfO2 and potential barrier modulation of the asymmetric TiO2HfO2 tunnel barrier. The rectification ratio up to 103 is capable of realizing a single-crossbar array up to 16 Mb for future high-density storage class memory applications.
- 3-D memory
- crossbar array
- resistive-switching memory (RRAM)