Etching with Hydrofluoric Acid

Photoresists, developers, remover, adhesion promoters, etchants, and solvents ... Phone: +49 731 36080-409 www.microchemicals.eu e-Mail: [email protected] Etching of SiO2, Quartz, and Glasses with HF Hydrofluoric acid is the only etchant which attacks amorphous SiO2, quartz, or glasses at significant high etch rate. However, HF is not only a strong corrosive, but also highly toxic towards higher concentrations: Local effects include tissue destruction and necrosis, deaths have been reported from concentrated acid burns to as little as 2.5 % body surface area. Besides personal protective equipment, it’s recommended not to handle higher concentrations of HF than required, and use ready-diluted mixtures instead of making own dilutions. We supply HF in a concentration of 1, 10, and 50% as well as buffered HF (BOE 7 : 1) in semiconductor-quality (VLSI). The following sections deal with common questions and problems concerning HF-etching with photoresist masks.