Alternating multi-pulse atomic layer deposition for dopant tailoring in sub-10 nm ferroelectric thin films
Journal
Materials Today Chemistry
Journal Volume
43
Start Page
102459
ISSN
2468-5194
Date Issued
2025-01
Author(s)
DOI
10.1016/j.mtchem.2024.102459
Abstract
Zr-doped HfO2-based ferroelectric materials demonstrate substantial potential for next-generation nonvolatile memory applications. However, the layer-by-layer doping method used in conventional atomic layer deposition (ALD) is restricted by the finite number of available deposition cycles for doping, which obstructs the progress of ultrathin films necessary for scaling down devices. In this paper, we propose a novel alternating multi-pulse (AMP) ALD approach that incorporates Zr doping into each ALD cycle, resulting in a homogeneous dopant distribution throughout the film thickness and improved areal coverage of precursors. By alternating the pulsing sequence of Hf and Zr precursors in each ALD cycle, significant ferroelectricity is achieved in the thin film with a high Zr/Hf ratio. Furthermore, a multi-pulse doping model is developed to elucidate the doping mechanism in AMP ALD, which is supported by the atomic percentages obtained from X-ray photoelectron spectroscopy and the measured growth rate per cycle. The AMP ALD technique provides an innovative solution for achieving continuous and tunable doping, rather than discrete or digital doping, which is critical for ultra-scale materials and devices.
Subjects
Alternating multi-pulse doping
Atomic layer deposition
Ferroelectricity
Nanoscale thin films
Zr-doped HfO2
SDGs
Publisher
Elsevier BV
Type
journal article