A refined oxidation-stripping technique of thin n-type Si films

Abstract

When energetic ions are implanted in Si-crystals an anodization-peeling technique can be used as a precise tool for the determination of the ion concentration profiles, when proper precautions are taken. Anodic oxidation rates of N-type silicon in ethylene glycol solution have been studied using neutron activation analysis and it has been found that three factors, namely chemical pretreatment, illumination, and temperature seem to have the greatest influence on the anodization process and the reproducibility. Furthermore, by using a chemical posttreatment, involving evaporation of the liquid before the activity is measured, an error of less than ± 2% for an anodic voltage of 180 V has been obtained. In addition, some data on oxidation in water, and on etching of Si in hydrofluoric acid are presented.