Programmable Ferroelectric HZO NEMS Mechanical Multiplier for in-Memory Computing

This work presents the first-ever NEMS-based in-memory computing device that uses ultra-thin ferroelectric hafnium zirconium oxide (HZO) as the weight storage unit. The HZO unimorph’s piezoelectric properties can be tuned by applying a poling voltage (Vp) from -8V to 8V across a 20-nm HZO film. The unimorph displacement, both at resonance and off-resonance, is found to be proportional to the product of Vp and Vin, where Vin is the input drive voltage when operating in compute mode. The NEMS device demonstrates analog multiplication, without electrical contacts, and consumes attoJoules of energy. The HZO-based unimorphs are scalable to nano-scale dimensions owing to the ultrathin HZO layer. This device provides the possibility of arraying of the unimorphs with capacitive readout for massively parallel MAC (Multiply and Accumulate) units.