InGaZnO Synaptic Transistor Using Metal-Hydroxyl Traps at Back Channel for Weight Modulation

Synaptic devices are essential for constructing neuromorphic computing. For the current synaptic transistors, their gate dielectrics are always required to possess special functions (e.g., ion migration and charge trapping) for realizing weight modulation, which degrades the carrier mobility and thus the device performance due to the Coulomb scattering. A new synaptic transistor is presented to address this issue. This device uses the metal-hydroxyl (M-OH) defect at the back channel rather than the gate dielectric for weight modulation. Driven by the gate voltage, electron trapping, and detrapping occur in the M-OH defect, which changes the channel carrier density to result in a delicate weight modulation. This transistor displays relatively high carrier mobility by suppressing the Coulomb scattering existing in the current synaptic transistors. Typical synaptic functions are also well demonstrated for this device. Moreover, simulation results prove that this synaptic transistor can provide high recognition accuracy for neuromorphic computing.