Buffered oxide etchant (BOE) 61 can be used in the oxide removal of AlGaNGaN-based high electron mobility transistors for gate photolithography. It can be used in a buffer oxide etchant method for the fabrication of micro biochip.

To selectively etch silicon dioxide layers while maintaining a controlled and uniform etching rate.

BOE 61 is 6 parts by volume 40% ammonium fluoride and 1 part by volume 49% HF.Buffered oxide etchant (BOE) 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). Concentrated HF etches silicon dioxide too quickly for good process control and also peels photoresist used in lithographic patterning.