[mems-talk] Another question about silicon dioxide wet etching

[Qiao Dayong]

After the NH4F, HF and glycerine being mixed together, stirring is needed and the
mixture should not be used until the next day to assure that the glycerine has
been completely mixed with the other two. If not, the etching rate of oxide and
aluminium is not the same through the whole ethant, higher or slower than the
average, maybe that is why you got the abnormal results.