Laser-Induced Phase Control of Morphotropic Phase Boundary Hafnium-Zirconium Oxide

ACS Appl Mater Interfaces. 2025 Jan 2. doi: 10.1021/acsami.4c10813. Online ahead of print.

Abstract

A novel approach to delicately control the phase of a ferroelectric has been developed using a continuous-wave laser scanning annealing (CW-LSA) process. After proper process optimization, the equivalent oxide thickness (EOT) of 3.5 Å with a dielectric constant (κ) of 68 Å is achieved from HZO in a metal-ferroelectric-metal (MFM) capacitor structure. The leakage current density (Jg = 4.6 × 10-5 A/cm2 at +0.8 V) was four times lower compared to the reference group treated with an optimized RTA process. The outstanding electrical characteristics of the 6 nm HZO film were attributed to the stable formation of the morphotropic phase boundary (MPB) structure, which was enabled by the directional scanning nature of the CW-LSA process.

Keywords: HZO; MFM capacitor; continuous-wave laser scanning annealing; high-κ materials; morphotropic phase boundary.