Understanding of polarization reversal and charge trapping under imprint in HfO2-FeFET by charge component analysis

Abstract

Polarization reversal and charge trapping under imprint in HfO2-based ferroelectric FET (FeFET) are studied by charge component analysis. By decomposing the effects of spontaneous polarization and charge trapping using the transient current measurement with triangle waves in both metal–ferroelectric–metal (MFM) and metal–ferroelectric–insulator-Si (MFIS) capacitors, we found that V th under imprint in MFIS is determined by both coercive voltage (V c) shift due to imprint and the subsequent modulation of charge trapping at the same polarization. In addition, a comparison of V c shift due to imprint of MFM and MFIS was performed. V c shift of MFIS was found to be in good agreement with that of MFM. This implies that the imprint in FeFET can be predicted from MFM even though FeFET has a complex structure with an interfacial layer.