Wang, Ting-YunTing-YunWangLin, Yun-HsuanYun-HsuanLinChuang, Chun-HoChun-HoChuangMIIN-JANG CHEN2025-11-272025-11-272025-11-1009258388https://www.scopus.com/record/display.uri?eid=2-s2.0-105020260014&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/734179We 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.falseAtomic layer depositionFerroelectricityHfxZr1-xO2Monolayer engineeringMulti-pulse ALDjournal article10.1016/j.jallcom.2025.1846582-s2.0-105020260014