B.O.E.s (Buffered Oxide Etch)
Buffered Oxide Etch (B.O.E.) is a buffered HF mix which controls and slows down the attack rate of HF on oxide. The wet etchant is often used in microfabrication applications. It’s used primarily for etchings on polysilicate glasses, SiO2 films, and quartz. Buffered oxide etch rate can go up to 70-90 nm per minute depending on the SiO2 morphology and temperature.
B.O.E. is a combination of a buffering agent like hydrofluoric acid (HF) and ammonium fluoride (NH4F). They come ready to use, and are highly compatible with a broad range of photoresists.
The colorless liquid is water-soluble and remains stable at room temperature when proper storage and use protocols are followed. B.O.E. can release toxic fumes made up of nitric oxides, ammonia, and fluorides when heated to decomposition.
It should not be exposed to heat, moisture, and incompatible substances like leather, rubber, most common metals, hydroxide, sulfuric acid, ammonia, calcium oxide, phosphorus pentoxide, arsenic trioxide, sodium, vinyl acetate, ethylenediamine, alkalis, organic materials, strong bases, water, sulfides, carbonates, cyanides, acetic anhydride, and oxides of silicon like glass, concrete, silica, and fluorine.