ROLE OF LIGHT IN THE FORMATION OF POROUS SILICON ON P-TYPE SUBSTRATES

The mechanisms of the influence of illumination on the formation Of Porous silicon layers during anodization of p-type silicon has been analyzed. The stage of additional oxidation of silicon from the doubly charge state to the quadruply charged state could involve participation of a solid phase, which was a light-sensitive catalyst of the process. Uniform illumination of the substrate enhanced this process and as a consequence it increased the porosity and the photoluminescence emitted by such layers. Nonuniform illumination of the substrate resulted in a redistribution of porous silicon over the surface area of a sample and it altered its structure.