 Buffered oxide etch

Buffered oxide etch (BOE), also known as buffered HF or BHF, is a wet etchant used in microfabrication.Its primary use is in etching thin films of silicon dioxide (SiO2) or silicon nitride (Si3N4).It is a mixture of a buffering agent, such as ammonium fluoride (NH4F), and hydrofluoric acid (HF).