Atomic-scale tailoring of sub-4 nm ferroelectric films via multi-pulse doping and monolayer control
Journal
Journal of Alloys and Compounds
Journal Volume
1045
Start Page
184658
ISSN
09258388
Date Issued
2025-11-10
Author(s)
Abstract
We demonstrate a novel method to enhance ferroelectric properties in ultra-thin (<4 nm) HfxZr1-xO2 films using multi-pulse atomic layer deposition (ALD) and monolayer engineering. By employing a multi-pulse ALD technique in which the Zr pulse precedes the Hf pulse, Zr-rich HfxZr1-xO2 thin films with homogeneous doping along the growth direction were synthesized. The further incorporation of a ZrO2 seed layer prepared with an ALD cycle comprising double Zr pulses leads to significant enhancement in ferroelectric properties, achieving an impressive remnant polarization of 2Pr ∼ 30µC/cm2 at thicknesses below 4 nm without wake-up treatment. Microstructural characterizations by grazing incidence X-ray diffraction and high-resolution transmission electron microscopy confirm the improved orthorhombic phase formation and crystallinity. Quantitative X-ray photoelectron spectroscopy analysis reveals close agreement between the measured Zr/Hf ratios and the theoretical prediction based on the multi-pulse doping model. These results pave a scalable route for ultra-thin ferroelectric films in advanced semiconductor applications.
Subjects
Atomic layer deposition
Ferroelectricity
HfxZr1-xO2
Monolayer engineering
Multi-pulse ALD
Publisher
Elsevier Ltd
Type
journal article