Statistical approach to the RESET switching of the HfO2-based solid electrolyte memory

The RESET switching of an oxide-based bipolar solid electrolyte memory with the Cu/HfO
₂
/Pt structure is studied in this work. The parameters of the RESET point defined at the maximum of the RESET current evolution, RESET voltage (V
_RESET
) and RESET current (I
_RESET
), are analyzed with a statistical method. The experimental raw data show a U-shape relation between VRESET and the ON-state resistance (R
_ON
). After data correction by a series resistance (R
_S
), V
_RESET
is roughly constant and the RESET current (IRESET) is inversely proportional to R
_ON
. These behaviors are in agreement with the thermal dissolution model of RESET. The further statistical analyses in terms of Weibull distributions show that the R
_ON
distribution has a strong influence on the I
_RESET
and V
_RESET
distributions. By using a “resistance screening” method, the I
_RESET
and V
_RESET
distributions are found to be compatible with a Weibull model. The Weibull slopes of the I
_RESET
and V
_RESET
are independent on R
_ON
, indicating that the RESET point corresponds to the initial phase of CF dissolution, according to our cell-based RESET model for the unipolar VCM (valence change mechanism) device. On the other hand, the scale factor of the V
_RESET
distribution (V
_RESET63%
) is roughly constant, while the scale factor of the I
_RESET
(I
_RESET63%
) is inversely proportional to R
_ON
, which is consistent with the thermal dissolution model of RESET and our cell-based RESET model. The RESET switching of the studied oxide-based bipolar solid electrolyte memory is dominated by the thermal dissolution mechanism.