Impact of total ionizing dose irradiation on electrical property of ferroelectric-gate field-effect transistor

P-type channel metal-ferroelectric-insulator-silicon field-effect transistors (FETs) with a 300 nm thick SrBi2Ta2O9 ferroelectric film and a 10 nm thick HfTaO layer on silicon substrate were fabricated and characterized. The prepared FeFETs were then subjected to 60Co gamma irradiation in steps of three dose levels. Irradiation-induced degradation on electrical characteristics of the fabricated FeFETs was observed after 1 week annealing at room temperature. The possible irradiation-induced degradation mechanisms were discussed and simulated. All the irradiation experiment results indicated that the stability and reliability of the fabricated FeFETs for nonvolatile memory applications will become uncontrollable under strong irradiation dose and/or long irradiation time.