Modulation of Oxygen Content and Ferroelectricity in Sputtered Hafnia‐Zirconia by Engineering of Tungsten Oxide Bottom Electrodes

The well‐developed high‐k technologies ease the integration complexity for HfO 2 ‐based ferroelectric (FE) devices in the complementary metal‐oxide semiconductor processes. Sputtered Hf x Zr (1‐x) O 2 (HZO) FEs have proven their thermal compatibility in back‐end‐of‐line (BEOL) integration processes with high remanent polarization (P r ) and a high cycling endurance. With the help of a tungsten oxide (WO x ) bottom electrode, the sputtered HZO's FE properties are further advanced in this work. WO x is used to tune the oxygen content in the HZO film, providing an FE performance with a maximum 2P r of 46 µC cm − 2 and an endurance of 10 8 cycles. Based on this, sputtered HZO can compete with the atomic layer deposited HZO in the BEOL processes. In addition, WO x bottom electrodes enhance the FE capacitor behavior in a broad processing window, which relaxes the manufacturing restrictions.