CATALYSIS AND PORE INITIATION IN THE ANODIC-DISSOLUTION OF SILICON INHF

A mechanism for the (photo)anodic dissolution of silicon in KF contain ing solutions is proposed, which explains the dependence of both the p hotocurrent quantum yield and the efficiency for hydrogen evolution on the flux of absorbed photons. The model assumes that the chemical oxi dation of an Si(II) intermediate to an Si(IV) product, which is accomp anied by the formation of a hydrogen molecule, is catalyzed by a mobil e Si(I) dissolution intermediate. The surface chemistry, corresponding to the proposed mechanism of anodic dissolution, is discussed. Furthe rmore, it is shown that the mechanism may provide an explanation, base d on chemical kinetics, for initiation of pores during anodic etching.