Interdiffusion study in group IVB, VB and VIB refractory metal-silicon systems

TL;DR

This study investigates the interdiffusion of refractory metals with silicon, revealing systematic diffusion patterns across groups and providing insights into phase growth, diffusion parameters, and defect behavior in silicide formation.

Contribution

It offers a comprehensive analysis of diffusion behaviors in M/Si systems, including new data on Ti, Zr, Hf, Ta, and W, and compares these with existing results to identify periodic trends.

Findings

Systematic diffusion patterns with increasing atomic number.

Determined diffusion parameters such as activation energy and growth constants.

Enhanced understanding of phase growth kinetics and defect roles in silicide formation.

Abstract

The solid state interdiffusion in refractory metals and single crystal Si are studied in details by diffusion couple technique. The wide range of application and importance of silicides in various devices are the motivation for these studies. The refractory metals which are considered and compared in these M/Si systems (M = metal) are group IVB elements Ti, Zr and Hf, group VB elements V, Nb and Ta, group VIB elements Cr, Mo and W. Out of these systems, the Ti, Zr, Hf, Ta and W M-Si systems have been studied in this thesis. The results of V, Nb and Mo systems, which were studied before in our group, are compared with the result of present study and a systematic pattern in diffusion behavior is found with increasing atomic number of the elements, group-wise in the periodic table. These studies help to understand the growth kinetics of the phases formed, diffusion parameters, relative mobilities of the species and presence and behavior of the different defects in the crystal structure. The different diffusion parameters calculated in present study are, parabolic growth constants, integrated diffusion coefficients, activation energy for diffusion, ratio of tracer diffusivities and tracer diffusivity of the species