A New Metal–Ferroelectric(hboxPbZr₀.53hboxTi₀.47hboxO₃)–Insulator(hboxDy₂hboxO₃)–Semiconductor (MFIS) FET for Nonvolatile Memory Applications

Metal–ferroelectric–insulator–semiconductor (MFIS) field-effect transistors withhboxPb(hboxZr₀.53, hboxTi₀.47)hboxO₃ferroelectric layer and dysprosium oxidehboxDy₂hboxO₃insulator layer were fabricated. The out-diffusion of atoms betweenhboxDy₂hboxO₃and silicon was examined by secondary ion mass spectrometry profiles. The size of the memory windows was investigated. The memory windows measured from capacitance–voltage curves of MFIS capacitors andI_ DS–V_ GScurves of MFIS transistors are consistent. The nonvolatile operation of MFIS transistors was demonstrated by applying positive/negative writing pulses. A high driving current of 9$muhboxA/muhboxm$was obtained even for long-channel devices with a channel length of 20$muhboxm$. The electron mobility is 181hboxcm²/hboxV cdot hboxs. The retention properties of MFIS transistors were also measured.