TiNxOy/TiN dielectric contrasts obtained by ion implantation of O2+; structural, optical and electrical properties

The properties of TiN can be gradually transformed by O-2(+) implantations in the 10-40 keV range and fluences in the 5 x 10(13)-5 x 10(16) cm(-2) range. The resulting structure consists of shallow TiNxOy (TiNO)/TiN contrasts with increased resistivity on the top layer. In fact, oxygen actively replaces nitrogen in the implanted TiN region as illustrated by Rutherford backscattering spectrometry. N substitutions and vacancies in the lattice induce structural distortions and strain generation as illustrated by x-ray diffraction, high resolution transmission electron microscopy and Raman spectroscopy. The influence of these modifications in the optical and electrical properties was characterized by spectroscopic ellipsometry and four probe resistivity measurements. The proposed process, especially at the lower energy, is liable to help in the creation of electrical/photonic structures based in shallow TiNO/TiN electric/dielectric contrasts.