Effect of the copper plasma density on the growth of SiOx-Cu thin films by PLD

Abstract

Copper containing silicon oxide layers were grown by pulsed laser deposition. Silicon and copper targets were simultaneously ablated in order to combine both laser produced plasmas using a parallel configuration in an oxygen containing atmosphere at a fixed pressure of 20 mTorr. The plasmas were characterized independently using a Langmuir planar probe to calculate the mean kinetic energy and density of the silicon and copper ions. Fixed values for plasma parameters of Si were chosen while the Cu plasma density was varied from 0 to 1.7x1013 cm−3 with the aim to modify the Cu content on the films. Nanolayers of SiOx-Cu with thicknesses ranging from 50 to 110 nm were obtained. As Cu ion density increased, different Cu species (Cu and CuO) were incorporated into SiOx matrices with different Si/O atomic ratios, which were strongly affected by variations in Cu ion density.