Variation of surface properties of copper oxide thin films by nitrogen ion implantation

In this research, the effect of nitrogen ion implantation on the crystalline and surface structure of copper oxide thin film has been investigated. For this purpose, a thin film with a thickness of 150 nm was deposited on the silicon substrate by copper oxide sputtering method. Then, the nitrogen ion implantation was performed using an electrostatic accelerator with 50 keV energy for 3 seconds with a fluence of 2×1014 particles per square centimeter. The measured current in this experiment was obtained using a profile device and its fitting to a Gaussian function in the range of several milliamperes. From the results of XRD analyzes, it was observed that the number of peaks and the crystal structure have changed. The results of SEM analysis show that the surface structure is defected due to implantation and the measurement of AFM roughness parameters showed that the thin layer of copper oxide became more uniform after ion implantation and its roughness or stiffness is decreased. By measuring the energy gap of copper oxide, it was found that after ion implantation, its value increased from 2.26 eV to 2.34 eV, which can be tuned to make different types of sensors.