Improvement in ferroelectricity of HfxZr1−xO2thin films using ZrO2seed layer

The effect of crystallized ZrO 2 (ZrO 2 -seed), amorphous Hf 0.43 Zr 0.57 O 2 (HZO; HZO-seed), and amorphous Al 2 O 3 (Al 2 O 3 -seed) seed layers on the ferroelectricity of HZO films was investigated. The remanent polarization ( ) of a TiN-electroded capacitor with a ZrO 2 -seed layer was much larger than that of capacitors with a HZO-seed, Al 2 O 3 -seed, or no seed layer. Furthermore, the maximum 2 P r was exhibited when the thickness of the ZrO 2 -seed layer was 2 nm. Large grain growth was observed, which satisfied the same lattice pattern between ZrO 2 and HZO films, and indicates that the ZrO 2 seed layer plays an important role in the nucleation of the HZO film.