I am interested in etching rates of silicon dioxide in low concentrations of KOH. It looks from the literature I've seen that both etch rate (ER) in Si and SiO2 and the selectivity ER_Si:ER_SiO2 will go down with decrasing concentrations - but will this trend also hold when reaching the 1e-1 - 1e-5 wt%? Thanks Peter