We present a study on a weight-update characteristics which is dependent on a Hf doping concentration in a Hf-doped ZnO (Hf-ZnO) channel layer of synaptic thin-film transistors (Syn-TFTs). Here, when Hf doping concentration is increased, it is known t...
We present a study on a weight-update characteristics which is dependent on a Hf doping concentration in a Hf-doped ZnO (Hf-ZnO) channel layer of synaptic thin-film transistors (Syn-TFTs). Here, when Hf doping concentration is increased, it is known that the disorders (e.g. dangling bond) in Hf-ZnO channel layer are suppressed due to an addition of Hf cation. This can be expected that an electron mobility is improved while reducing sub-threshold slope (SS) because of the decreased parasitic capacitance. With the decreased SS, it can be expected that a weightupdate characteristics (e.g. a dynamic ratio, dr<SUB>w</SUB>) is also more improved due to a relatively high sensitivity. To check these, static and pulsed characteristics are monitored with two cases of the fabricated Syn-TFTs, based on a high doped Hf-ZnO (Hf-ZnO(H)) and low doped Hf-ZnO (Hf-
ZnO(L)).