OFF-State Behavior in MFIS Structure: In the OFF-state of the FTJ with the MFIS structure, a depletion layer near the interface of ZrO2 and n-type polysilicon results in more significant band bending compared to the TiN bottom electrode in the MFIM structure. The higher band diagram increases the average energy barrier along the direction from the conduction band of n-type polysilicon to the TiN electrode. This higher energy barrier helps to suppress tunneling current in the OFF-state.