Reliable multilevel memristive neuromorphic devices based on amorphous matrix via quasi-1D filament confinement and buffer layer

Abstract

Conductive-bridging random access memory (CBRAM) has garnered attention as a building block of non–von Neumann architectures because of scalability and parallel processing on the crossbar array. To integrate CBRAM into the back-end-of-line (BEOL) process, amorphous switching materials have been investigated for practical usage. However, both the inherent randomness of filaments and disorders of amorphous material lead to poor reliability. In this study, a highly reliable nanoporous–defective bottom layer (NP–DBL) structure based on amorphous TiO 2 is demonstrated (Ag/a-TiO 2 /a-TiO x /p-Si). The stoichiometries of DBL and the pore size can be manipulated to achieve the analog conductance updates and multilevel conductance by 300 states with 1.3% variation, and 10 levels, respectively. Compared with nonporous TiO 2 CBRAM, endurance, retention, and uniformity can be improved by 10 6 pulses, 28 days at 85°C, and 6.7 times, respectively. These results suggest even amorphous-based systems, elaborately tuned structural variables, can help design more reliable CBRAMs.

Conductive Bridge Random Access Memory (CBRAM): Challenges and Opportunities for Memory and Neuromorphic Computing Applications

“…To address this issue, a number of approaches have been implemented. One of the most efficient approaches is to limit the formation of the CF to a specific predefined path in the switching layer [ 59 , 60 ]. Abbas et al used a solution-processed rutile TiO 2 (r-TiO 2 ) to create the predefined channels in the r-TiO 2 switching layer [ 61 ].…”

A high linearity and multilevel polymer-based conductive-bridging memristor for artificial synapses

“…Constructing a single ion transport and filament growth channel in the resistive switching layer, such as growing dislocation pipes in the resistive switching layer and growing pores connecting the top and bottom electrodes by electrochemical corrosion technology, can enhance switching uniformity and long retention/high endurance. 32,33 Silver (Ag) alloyed with copper (Cu) can form alloying conductive channels to realize uniform gradual switching and great retention. 34 The introduction of metal ion diffusion barrier layers can realize precise atomic-level control and improve device uniformity and conductance control.…”

A non-volatile bipolar optical fiber memory based on phase change materials

“…[5] Characterized by exceptional programmability and non-volatility, PCMs offer computing speeds of up to 200 ns for allphoton computing. [6] Leveraging the optical properties of these materials, the integration of memory with computation, [7] featuring autonomous learning abilities and information recognition functions, has been achieved, thus surmounting the constraints imposed by the von Neumann bottleneck. [8] b hanyang_li@qq.com Operation principle of the all-fiber memory operation.…”