Optical Investigation of Silicon Implanted with High Doses of Oxygen and Hydrogen Ions

Abstract

Silicon layers implanted with high doses of oxygen and hydrogen ions (separately and consequently) were investigated by IR-spectroscopy technique. The absorption bands centered at 615, 630, 890, and 2110 cm⁻¹ were observed in the case of only hydrogen implantation. The bands centered at 460, 800, and 1060 cm⁻¹ were detected in the case of irradiation with O ⁺ ions. Transmission spectra show the interaction between oxygen and hydrogen implanted both to oxygen bedding region and “behind” of it. The interaction follows from the facts: intensity of the band centered at 890 cm⁻¹ increases, while the 615 cm⁻¹ band disappears, and intensity of the 630 cm⁻¹ band decreases. Measurements of the transmission spectra during thin removal of the implanted layers permit to draw and to analyze oxygen and hydrogen states distribution profiles before and after interaction. The result of interaction is different in the cases of hydrogen implantation to the oxygen bedding region and “behind” of it, but in both cases the oxygen removal from the surface to the deeper layers occurs. The observed changes of the bands centered at 615, 630 and 890 cm⁻¹ are caused probably by the formation of defect complexes similar to E′H center (O ₃ — S _i — H). The obtained profiles of the oxygen and hydrogen states before and after interaction can be used for simulation of the processes taking place during Si oxide profile transformation by following hydrogen implantation.