Impact of CF4/O2 Plasma Passivation on Endurance Performance of Zr-Doped HfO2 Ferroelectric Film

The impact of fluorine (CF4) and oxygen (O2) plasma passivation on HfZrOx(HZO)-based ferroelectric capacitor was investigated. When fabricating the capacitor, the order of passivation treatment was varied to improve the endurance characteristic. In detail, the CF4/O2 plasma treatment was applied to one of the three different layers (i.e., 1) Si substrate; 2) dielectric, and 3) HZO layer in the capacitor). Those capacitors were annealed at three different temperatures, i.e., 400 °C, 500 °C and 600 °C. The pristine remnant polarization (2Pr) of capacitors was improved with CF4/O2 passivation. However, the endurance performance was varied depending on various fabrication conditions. The capacitor with the CF4/O2 plasma treatment on Si substrate showed two orders of magnitude improvement in its endurance performance. The order of passivation significantly affected the ferroelectric properties. This is due mainly to the variation of atomic bonding of Hf/Zr and O atoms in HZO layer. The variation of atomic bonding was quantitatively confirmed by XPS analysis.