The
involvement of unwanted subcycling behavior in endurance cycling
of HfO2-based ferroelectric thin films is detrimental to
the reliability performance of nonvolatile memory devices. Subcycling
is also critical for emerging neuromorphic applications as well as
multilevel memory cells, which are deliberately operated in subloops
of the polarization hysteresis. There is a substantial mismatch between
the proven application potential and the lack of basic studies on
subcycling behavior. In this work, the temperature-dependent subcycling
behavior of a 5 mol % Si-doped HfO2 ferroelectric thin
film is investigated by carefully comparing the evolution of P–E and I–E hysteresis loops during subcycling at 80–350 K.
The switching density distributions before and after 108 subcycles at various temperatures are characterized using first-order
reversal curve measurements to reveal the changes in the coercive
field and internal bias fields. Based on a defect segregation-induced
local bias field model, the establishment of different local bias
fields during subcycling and its temperature dependence are thoroughly
discussed.