Application

Buffered oxide etchant (BOE) 10:1 can be used in the etching of titanium carbide, which can be used in microelectromechanical systems (MEMS). It can also be used in the etching of spin-on-dopant (SOD) for the development of conductor-insulator-conductor tunneling diodes. It can also be used to enhance the surface of fused quartz devices.

General description

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.