Phase stability of hafnium oxide and zirconium oxide on silicon substrate

TL;DR

This study investigates the phase stability of hafnium and zirconium oxides on silicon substrates using first-principles and thermodynamic modeling, providing insights into their stability and silicide formation during thin film processing.

Contribution

It offers a combined first-principles and thermodynamic approach to analyze phase diagrams and stability of Hf-Si-O and Zr-Si-O systems relevant to semiconductor applications.

Findings

HfO₂/Si and ZrO₂/Si interfaces are stable over wide temperature ranges.

Silicide formation can occur at low temperatures, especially at the HfO₂/Si interface.

The stability depends critically on the relative stability of metal silicates versus binary oxides.

Abstract

Phase stabilities of Hf-Si-O and Zr-Si-O have been studied with first-principles and thermodynamic modeling. From the obtained thermodynamic descriptions, phase diagrams pertinent to thin film processing were calculated. We found that the relative stability of the metal silicates with respect to their binary oxides plays a critical role in silicide formation. It was observed that both the HfO$_2$/Si and ZrO$_2$/Si interfaces are stable in a wide temperature range and silicide may form at low temperatures, partially at the HfO$_2$/Si interface.