  Tantalum nitride thin films have been grown by in situ nitrogen implantation
of metallic tantalum at room temperature over the energy range of 0.5-5keV.
X-ray photoelectron spectroscopy (XPS) and Factor Analysis (FA) have been used
to characterise the chemical composition of the films. The number of the
different Ta-N phases formed during nitrogen implantation, as well as their
spectral shape and concentrations, have been obtained using principal component
analysis (PCA) and iterative target transformation factor analysis (ITTFA),
without any prior assumptions. According to FA results, the composition of the
tantalum nitride films depends on both the ion dose and ion energy, and is
mainly formed by a mixture of metallic tantalum, beta-TaN0.05, gamma-Ta2N and
cubic/hexagonal TaN phases.
