[17a-M_278-1~13] CS.3 Code-sharing Session of 6.1 & 13.3 & 13.5

11:15 AM - 11:30 AM JST(2:15 AM - 2:30 AM UTC)Presentation by Applicant for JSAP Young Scientists Presentation Award

[17a-M_278-9] Understanding Depth Profile of Crystal Phases in Ferroelectric Hf_xZr_1-xO₂ Thin Films Capped with Topmost ZrO₂ Layer

〇Rina Takahisa¹, Takashi Onaya^1,2, Atsushi Tamura¹, Koji Kita¹ (1.GSFS, Univ. of Tokyo, 2.NIMS)

Keywords:

atomic layer deposition,HfO2-based ferroelectric thin film

We have previously reported that the ferroelectric properties of Hf_xZr_1-xO₂ (HZO) thin films formed by atomic layer deposition (ALD) are significantly enhanced by stacking a ZrO₂ layer on the topmost surface of a 10 nm HZO solid solution film followed by heat treatment. While it is evident that the topmost ZrO₂ layer plays a role in promoting and stabilizining the formation of the orthorhombic (O) phase, which is the ferroelectric phase, it remains unclear whether this effect is localised to the topmost surface only or extends throughout the entire film. In this study, we focused on the fact that the reduction in X-ray diffraction (XRD)peak intensity after etching the surface reflects the average presence of crystalline phases at each depth. By repeatedly etching the film surface by ~nm, the approximate crystalline phase distribution was determined from XRD analysis. This enabled investigation into whether the topmost ZrO₂ layer influences the depth profile of each crystalline phase in the HZO thin film, and how this influence differs from that of the topmost HfO₂ layer.