20:1 Buffered oxide etch | Stanford Nanofabrication Facility

Preferred Short Name:

20:1 BOE

Chemical Formula:

38% NH₄F, 2% HF, 60% H₂O

Full Chemical Name:

38% ammonium fluoride, 2% hydrofluoric acid, 60% water

BOE (Buffered Oxide Etch) is an HF based etchant, typically used to etch oxides. The buffer helps to reduce the impact to resist during etching.

Equipment name & NEMO ID	Training Required & Charges	Cleanliness	Location	Chemicals	Notes
Wet Bench Clean_res-hf wbclean_res-hf	Wet Bench Clean Piranha/HF/Phosphoric Training 2.25 hours	Clean	SNF Paul G Allen L107 Cleanroom	20:1 BOE 50:1 HF 6:1 BOE	Resist as mask allowed
Wet Bench CMOS Metal wbclean3	Wet Bench CMOS Metal (wbclean3) Training	Semiclean	SNF Paul G Allen L107 Cleanroom	20:1 BOE 50:1 HF 6:1 BOE Al-Etch Ti-Etch W-etch	Al, Ti, or W wet etching or oxide etching
Wet Bench Flexcorr 1 wbflexcorr-1	Wet Bench Flexcorr 1and2 and 3and4 Training 2.00 hours	Flexible	SNF Paul G Allen L107 Cleanroom	Acids Bases Gold Etchant 20:1 BOE 50:1 HF 6:1 BOE 9:1 Piranha Al-Etch Chrome Etch KOH SC1 SC2	Manual wet etching of non-standard materials. Hot plate available. GaAs allowed in personal labware only.