Hybrid Analog-Digital Learning with Differential RRAM Synapses

T. Hirtzlin (1) , Marc Bocquet (2) , M. Ernoult (1) , J.-O Klein (1) , E. Nowak (3) , E. Vianello (3) , J.-M Portal (2) , D. Querlioz (1)

1 C2N (UMR_9001) - Centre de Nanosciences et Nanotechnologies
2 IM2NP - Institut des Matériaux, de Microélectronique et des Nanosciences de Provence
3 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information

Exploiting the analog properties of RRAM cells for learning is a compelling approach, but which raises important challenges in terms of CMOS overhead, impact of device imperfections and device endurance. In this work, we investigate a learning-capable architecture, based on the concept of Binarized Neural Networks, which addresses these three issues. It exploits the analog properties of the weak RESET in hafnium-oxide RRAM cells, but uses exclusively compact and low power digital CMOS. This approach requires no refresh process, is more robust to device imperfections than more conventional analog approaches, and we show that due to the reliance on weak RESETs, the devices show outstanding endurance that can withstand multiple learning processes.

Domaines: Micro et nanotechnologies/Microélectronique

T. Hirtzlin, Marc Bocquet, M. Ernoult, J.-O Klein, E. Nowak, et al.. Hybrid Analog-Digital Learning with Differential RRAM Synapses. 2019 IEEE International Electron Devices Meeting (IEDM), Dec 2019, San Francisco, United States. ⟨10.1109/IEDM19573.2019.8993555⟩. ⟨hal-02399624⟩