Maxwell Giammona, Vidushi Sharma, et al.
ACS Fall 2023
Ferroelectric Tunnel Junctions (FTJs) are a candidate for the hardware realization of synapses in artificial neural networks. The fabrication process for a 784 × 100 crossbar array of 500 nm large FTJs, exhibiting effective On/Off currents ratio in the range 50–100, is presented. First, the epitaxial 4 nm-BiFeO3/Ca0.96Ce0.04MnO3//YAlO3 is combined with Ni electrodes. The oxidation of Ni during the processing affects the polarity of the FTJ and the On/Off ratio, which becomes comparable to that of CMOS-compatible HfZrO4 junctions. The latter have a wider coercive field distribution: consequently, in test crossbar arrays, BiFeO3 exhibits a smaller cross-talk than HfZrO4. Furthermore, the relatively larger threshold for ferroelectric switching in BiFeO3 allows the use application of half-programming schemes for supervised and unsupervised learning. Second, the heterostructure is combined with W and Pt electrodes. The design is optimized for the controlled collapse chip connection to neuromorphic circuits. Graphical abstract: [Figure not available: see fulltext.]
Maxwell Giammona, Vidushi Sharma, et al.
ACS Fall 2023
Sara Capponi
ACS Fall 2023
Craig Mahlasi, Sibusisiwe Makhanya, et al.
AGU Fall 2023
Daiki Kimura, Tatsuya Ishikawa, et al.
IPSJ 2024