Al-doped and Deposition Temperature-engineered HfO2 Near Morphotropic Phase Boundary with Record Dielectric Permittivity (~68)

We report the realization of a HfO
2
-based dielectric with the highest permittivity (~68) among all the reported works, approaching their theoretical limit of 70 [Fig. 1]. This is enabled by the use of Al incorporation in HfO
2
films and the careful temperature engineering from 300 to 260 °C during the atomic layer deposition to realize morphotropic phase boundary (MPB), which provides a giant enhancement in dielectric response. With this ultra-high permittivity, our Al-doped HfO
2
near MPB films deposited at 270 °C with a physical thickness of 9.4 nm exhibit an ultra-low leakage current density of 1.5×10
⁻⁵
A/cm
²
at 1 V with an extremely small equivalent oxide thickness of 0.53 nm. These films are also able to endure a high operation voltage of 2.4 V for more than 5×10
¹⁰
cycles and 10 years at 0.01% failure rate and 0.1 cm
²
dielectric area, holding great promise to be one of the key enablers for future ultra-low power transistors and ultra-high density memories (i.e. DRAM).