>    I had a question about the susceptibility of parylene to the chemicals
TMAH (tetra methyl ammonium hydroxide) & BOE (buffered oxide etch : HF+H2O
+NH4F). Parylene was deposited in hollow silicon molds & needs to be
released by etching away the silicon & some intermediate silicon dioxide.
Need to know if the chemicals would attack the exposed parylene in the
process of etching silicon. Kindly respond.
>  - Asma

We have measure the following etch rates for Parylene C:

In 30% KOH, 80 C:  0.42 nm/min.
TMAH is probably similar to KOH and will of course vary with temperature and
concentration.

In 5:1 BHF:  0.16 nm/min

    --Kirt Williams, Ph.D.    consultant