The Multilayer Analysis of Molecular Effect in BF_2~- Implanted Silicon Using Ellipsometric Spectra

摘要

The damage layer of ion implantation has been supposed 50 differential zones to investigate the molecular effect of BF_2~+ implanted sillicon. The ellipsometric spectra (photon energy: 1.6-5.0 eV) were measured for samples implanted with 147 keV BF_2~+ molecular ions at the dose range from 3 × 10~(13) to 5 × 10~(15) ion/cm~2, and corresponding B~+ and F~+ atomic-ion implantation. The depth profiles of lattice damage as well as non- uniform of native oxide and component of interface can be calculated from the multilayer optical model, the spectroscopic el1ipsometric data and effective medium approximation (EMA) by means of our computer program. The analytical results are in agreement with results of Rutherford backscattering and channeling, and transmission electron microscopy measurements. It is obvious that the damage layer and amophous zone are formed at the top surface region, and a striking damage enhancement is observed at the surface of the sample implanted with BF_2~+.