Question

Concentrated HF is not used to etch SiO2 because​

Answer 1

Answer:

is it your answer..

Explanation:

hope you help this..

Answer 2

Hydrofluoric Acid

Explanation:

A very "selective" chemical for $SiO_{2}$ i.e. doesn't etch silicon in the least - is acid (HF). If used directly such etchant features a too fast and aggressive action on the oxide, making very difficult the undercut and therefore the linewidth control.

Both thermally grown and deposited $SiO_{2}$ are often etched in buffered acid or simply acid . However, etching of deposited films proceeds tons faster than that of the thermal oxide.

When silica $SiO_{2}$ is heated with fluoride (HF), it forms silicon tetrafluoride $SiF_{4}$. The $SiF_{4}$ formed during this reaction can further react with HF to make Hydrofluorosilicic acid.