Thickness Scaling of High‐Permittivity HfO 2 /ZrO 2 Superlattice Capacitors With Morphotropic Phase Boundary

ABSTRACT HfO 2 /ZrO 2 superlattice (SL) materials hold significant promise for high‐performance electronics, primarily due to their low‐power consumption and seamless compatibility with complementary metal‐oxide‐semiconductor (CMOS) technologies. However, the stringent requirements for dimensional scaling and high‐density integration in advanced memory technologies have made it urgent to overcome the challenge of thickness scaling while maintaining high permittivity. In this work, we experimentally demonstrate thickness‐scaled HfO 2 /ZrO 2 SL films with thicknesses of 7.5 and 5 nm, which exhibit high permittivity values ( κ ) exceeding 75 and 68, respectively. These results were achieved by leveraging morphotropic phase boundary (MPB) engineering through optimized HfO 2 /ZrO 2 sublayer stacking in conjunction with process optimization, including the tuning of HfO 2 /ZrO 2 superlattice periodicity and annealing temperatures. Owing to the enhanced κ values and reduced film thickness, these SL films maintain low leakage current and robust endurance up to 10 11 cycles. Moreover, systematic electrical characterization reveals outstanding thermal stability across a broad temperature range from 4 to 425 K, alongside excellent device reliability. This work highlights the scaling potential of high‐ κ SL materials, providing a viable pathway for the next generation of low‐power logic and embedded memory applications.