Effect of hydrogen derived from oxygen source on low-temperature ferroelectric TiN/Hf0.5Zr0.5O2/TiN capacitors

초록

The ferroelectric (FE) properties of 10-nm-thick Hf0.5Zr0.5O2 (HZO) films deposited by an atomic layer deposition technique were improved by adopting O-3 as an oxygen source instead of H2O. All HZO films were annealed at 400 degrees C for 1 min in an N-2 atmosphere after TiN top electrode deposition. Regardless of the oxygen source, the HZO films exhibited the formation of a noncentrosymmetric orthorhombic phase, which is responsible for FE behavior with the suppression of the monoclinic phase. However, compared to the O-3-based HZO film, it was confirmed that the H2O-based HZO film was more incorporated with hydrogen derived from H2O, thereby degrading FE polarization and leakage behavior. The results indicate that the strategy of using O-3 as the oxygen source is useful for the fabrication and integration of FE HZO films for next-generation memory applications.

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