Ar ions irradiation effects in ZrN thin films grown by pulsed laser deposition

Thin ZrN films (<500 nm) were grown on (1 0 0)Si substrates at a substrate temperature of 500 °C by the pulsed laser deposition (PLD) technique using a KrF excimer laser under CH4 or N2 atmosphere. Glancing incidence X-ray diffraction showed that films were nanocrystalline, while X-ray reflectivity studies indicated that the films were very dense and with a smooth surface. The films were used to study the effect of 800 keV Ar ion irradiation on their structure and properties. After irradiation with a dose of 1014 at/cm2 the lattice parameter and crystallites size did marginally change. However, after irradiation with a 1015 at/cm2 dose, a clear increase in the lattice parameter accompanied by a significant decrease in nanohardness and Young modulus were observed.