Here, we report on the fabrication of a low temperature (< 300 °C) surface layer of silicon oxide on Si substrates, using the plasma immersion ion implanter Pulsion®. Before each implant, a chemical solution was used to remove the native silicon oxide. Oxygen implant conditions were optimized in order to obtain a thin oxide layer (< 10 nm) at the wafer surface. We used O2 as gas precursor and a negative voltage of 1 kV to extract ions from the plasma. The implantations were performed with the substrate heated to 100 °C or 300 °C with different plasma conditions. The oxygen concentration profiles were measured by Secondary Ion Mass Spectrometry. To study the chemical composition of the surface layer, we analysed the substrates using X-Ray Photoelectron Spectrometry. In addition, the roughness of the surface was characterized by Atomic Force Microscopy. Our results show that using Pulsion® tool we are able to produce oxide layers having the stoichiometric SiO2 composition already at the as-implanted state. In terms of roughness, the implanted wafers are comparable to pristine substrates.