Direct Measurement of Transient Charging and Dipole Alignment Speed in Ferroelectric Hf _0.5 Zr _0.5 O ₂ Gate Dielectric Using Graphene FETs

A novel method to analyze the ferroelectric switching behaviors of Hf 0.5 Zr 0.5 O 2 (HZO) gate dielectric is developed using the unique charge response characteristics of graphene field effect transistor (GFET). The linear density of state of graphene in a low V g region enables a detailed transient analysis of the effects of transient charging and dipole switching. The trans‐conductance of GFET with ferroelectric HZO is observed to be increased by 610% in DC measurement with a minimal hysteresis as reported for negative capacitance FET. However, fast pulse I – V analysis reveals that the improved swing and small hysteresis of GFET with ferroelectric HZO are the result of compensation between the bulk charge trapping and dipole charges.