Khalid Abdulla, Andrew Wirth, et al.
ICIAfS 2014
Two-terminal ferroelectric synaptic weights are fabricated on silicon. The active layers consist of a 2 nm thick WOx film and a 2.7 nm thick HfZrO4 (HZO) film grown by atomic layer deposition. The ultra-thin HZO layer is crystallized in the ferroelectric phase using a millisecond flash at a temperature of only 500 °C, evidenced by x-rays diffraction and electron microscopy. The current density is increased by four orders of magnitude compared to weights based on a 5 nm thick HZO film. Potentiation and depression (analog resistive switching) is demonstrated using either pulses of constant duration (as short as 20 nanoseconds) and increasing amplitude, or pulses of constant amplitude (+/−1 V) and increasing duration. The cycle-to-cycle variation is below 1%. Temperature dependent electrical characterisation is performed on a series of device cycled up to 108 times: they reveal that HZO possess semiconducting properties. The fatigue leads to a decrease, in the high resistive state only, of the conductivity and of the activation energy.
Khalid Abdulla, Andrew Wirth, et al.
ICIAfS 2014
Ken C.L. Wong, Satyananda Kashyap, et al.
Pattern Recognition Letters
Ryan Johnson, Ippokratis Pandis
CIDR 2013
Svenja Mauthe, Philipp Staudinger, et al.
CLEO 2019