Specific Process Knowledge/Etch/Wet Silicon Oxide Etch (BHF)

Wet Silicon Oxide Etch (BHF and SIO Etch (wetting agent))

Wet Silicon Oxide Etch (BHF): positioned in cleanroom 3

Silicon oxide can be etched using HF. At Danchip it is mainly used in a buffered version BHF (premixed). The BHF has a more stabil etch rate and has a high selectivty of oxide compared to photoresist which makes photoresist a good masking material for the oxide etch. However etching down to a silicon surface BHF leaves the siliocn surface slightly more rough than a pure HF solution.

SIO etch (BHF with wetting agent) can also be used for etching silicon oxide. This is mainly for etching small holes (~<?)