In conclusion, it was noted that the (111) orientation of the HZO film was inappropriate for o-phase formation due to the almost equivalent tensile strain along the a-, b-, and c- axis. Using highly (111)-textured Pt BE films, highly (111)- textured t-phase HZO films were deposited. Even though the HZO films on the Pt BE showed an almost equivalent ein value compared to those on the TiN BE, and a small enough average grain size to induce the t-phase (and subsequently, the o-phase, if the strain condition was appropriate), they did not show ferroelectricity at all. Based on the results, it was concluded that the origin of the formation of the unstable o-phase under the ALD and the annealing conditions in this experiment was the large tensile strain along the c-axis of the t-phase, which could have been induced by the coales- cence of the nucleating grains. This insight provides a way to further enhance the ferroelectric performance of the HfO2-based thin films if their grain size and crystallographic orientations could be further optimized.
In conclusion, it was noted that the (111) orientation of the HZO film was inappropriate for o-phase formation due to the almost equivalent tensile strain along the a-, b-, and c- axis. Using highly (111)-textured Pt BE films, highly (111)- textured t-phase HZO films were deposited. Even though the HZO films on the Pt BE showed an almost equivalent ein value compared to those on the TiN BE, and a small enough average grain size to induce the t-phase (and subsequently, the o-phase, if the strain condition was appropriate), they did not show ferroelectricity at all. Based on the results, it was concluded that the origin of the formation of the unstable o-phase under the ALD and the annealing conditions in this experiment was the large tensile strain along the c-axis of the t-phase, which could have been induced by the coales- cence of the nucleating grains. This insight provides a way to further enhance the ferroelectric performance of the HfO2-based thin films if their grain size and crystallographic orientations could be further optimized.
正在翻譯中..