Crystallinity Effect on Electrical Properties of PEALD–HfO2 Thin Films Prepared by Different Substrate Temperatures

Abstract

Hafnium oxide (HfO2) thin film has remarkable physical and chemical properties, which makes it useful for a variety of applications. In this work, HfO2 films were prepared on silicon through plasma enhanced atomic layer deposition (PEALD) at various substrate temperatures. The growth per cycle, structural, morphology and crystalline properties of HfO2 films were measured by spectroscopic ellipsometer, grazing-incidence X-ray diffraction (GIXRD), X-ray reflectivity (XRR), field-emission scanning electron microscopy, atomic force microscopy and x-ray photoelectron spectroscopy. The substrate temperature dependent electrical properties of PEALD–HfO2 films were obtained by capacitance–voltage and current–voltage measurements. GIXRD patterns and XRR investigations show that increasing the substrate temperature improved the crystallinity and density of HfO2 films. The crystallinity of HfO2 films has a major effect on electrical properties of the films. HfO2 thin film deposited at 300 °C possesses the highest dielectric constant and breakdown electric field.

Structural changes in HfSe2and ZrSe2thin films with various oxidation methods

“…32,33 The change of structure is observed at 250–300 °C. This is consistent with previous reports 34,35 in which transitions to a crystalline structure at elevated temperatures have been observed for amorphous HfO 2 and ZrO 2 on a crystalline substrate. EDS analysis indicates that the samples are still oxidized, even after annealing in H 2 .…”

“…The amorphous oxide can be crystallized after annealing. 35 No cavities were observed, and EDS analysis shows a uniform composition (Fig. S14 and S15, ESI†).…”