Acid etching is available in our class 10 laminar flow benches. Rather than a conventional fume extraction hood these benches provide a constant downward stream of low velocity hepa filtered air.
Hydrofluoric acid (HF) etches.
We use buffered oxide etch (BOE) or buffered hydrofluoric etch (BHF) as a wet etchant for micro-fabrication in a dedicated laminar flow cabinet. Used for etching thin films of silicon dioxide (SiO2) or silicon nitride (Si3N4). The most commonly used is a 7% BHF to remove the native oxide layer before metallisation.
Chrome etch CR75 (ammonium ceric nitrate and perchloric acid) is used for mask making. Gold etch GE6 (Potassium iodide / Iodine) and Piranha etch (hydrogen peroxide and sulphuric acid) are normally used for the removal of organic residues.
The Dektak surface profilometer is capable of measuring surface topography features to below 100Å and surface roughness in the nanometer range. Currently fitted with a 12.5μm diameter high aspect ratio diamond stylus.