Microdetermination of silicon dioxide on the surface by sensors based on perfluorinated proton-conducting membranes

A microdetermination method of silicon dioxide on the silicon surface is studied. In this method, a thin SiO$_2$ layer is dissolved in an aqueous solution of hydrofluoric acid and then the resulting solution is analyzed with sensors based on perfluorinated proton-conducting membranes. Quantitative determination of silicon dioxide remaining on the silicon surface in a quantity as low as 1 $\times$ 10$^{-6}$ mol is demonstrated to be feasible.