Investigating the impact of 3D trench structures on HfO2-based ferroelectric capacitors

Abstract

Ferroelectric (Fe) devices with 3D trench structures are highly promising to fulfill the demand for high-density and low-power memory applications. However, the potential effects of structure-induced strain on the Fe films' properties remain unclear. This work investigates the homogeneity of HfO₂-based Fe trench capacitors across 2D planar to 3D trench structures. Systematic device characterization and temperature studies reveal consistent ferroelectric properties of the fabricated devices. Notably, the findings indicate that the large curvature of trench sidewalls minimally affects the ferroelectricity of HfZrO₂ (HZO) thin films, affirming their suitability for 3D structures. Meanwhile, the trench capacitors exhibit good reliability and retention characteristics, making them promising for high-density memory applications. This study provides valuable insights for 3D Fe capacitor development, emphasizing the potential of HfO₂-based Fe materials to advance memory technology.