Work

The formation mechanism and kinetics of Ni3GaAs nano-thin films on GaAs

Year: 2026

Type: article

Abstract: A thorough investigation of metal–semiconductor contacts is essential to advance the design and fabrication of ultra-scaled devices based on III–V compound semiconductors. The initial stages of growth and kinetics of the Ni₃GaAs phase at both coherent and incoherent Ni/GaAs interfaces have been studied primarily using in-situ X-ray diffraction (XRD) measurements, transmission electron microscopy (TEM), and atom probe tomography (APT) analysis. In this study, we validate the hypothesis that the variation of the XRD integrated intensity is proportional to the thickness of the formed phase through direct measurements using TEM and in situ XRD. In-situ XRD measurements during isothermal annealing at different temperatures were then performed on two samples (20 nm and 100 nm of Ni film) in order to monitor the growth kinetics of the only Ni3GaAs phase formed. These results show that only the Ni vacancy diffusion mechanism is dominant in this phase, and that there is a strong agreement in the Ni3GaAs growth kinetics between nano-thin-film and bulk diffusion couples. By comparing these findings with nucleation and growth models, we conclude that the growth of the Ni3GaAs phase at the Ni/GaAs interface is predominantly diffusion-controlled at low temperatures and greater thicknesses, whereas it is primarily governed by interface reactions at higher temperatures and lower thicknesses.

Source: Materialia

DOI: 10.1016/j.mtla.2026.102689