A New Metal–Ferroelectric$(hboxPbZr_0.53hboxTi_0.47hboxO_3)$–Insulator$(hboxDy_2hboxO_3)$–Semiconductor (MFIS) FET for Nonvolatile Memory Applications

Metal–ferroelectric–insulator–semiconductor (MFIS) field-effect transistors with
$hboxPb(hboxZr_0.53, hboxTi_0.47)hboxO_3$
ferroelectric layer and dysprosium oxide
$hboxDy_2hboxO_3$
insulator layer were fabricated. The out-diffusion of atoms between
$hboxDy_2hboxO_3$
and 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 and
$I_ DS$
–
$V_ GS$
curves 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 181
$hboxcm^2/hboxV cdot hboxs$
. The retention properties of MFIS transistors were also measured.