Porous silicon properties investigated by IR and UV-VIS spectrometry

IR and UV-VIS spectrometry were used to study the correlation between the anodization conditions and the structure of the porous silicon (PS). The specific surface area increase with the electric charge involved in the etching process. At the same time the total amount of SiH bonds in the PS layer depends on the value of the effective surface. The total electric charge passed through the sample has been related with integral IR absorbances of the Si-H and Si-H₂ bands. An approximately linear function was obtained, especially for SiH. The reactivity of the PS layer related with the anodization conditions have been studied using the behaviour of the Si-O-Si bands after the oxidation in air. The UV-VIS reflection spectrometry shows an interference patterns obtained in the case of a shallow porosity