Hi,


I recently deep etched two Si samples. I used the same recipe as before exepted
for one parameter. After etching, the silicon surface (not the photoresist
mask...) was covered with a powder-like yellow film. I don't understand why.

For the firt sample, the coil power was raised to 700W (instead of 600) during
passivation

and for the second sample, the platen (electrods) power was decreased to 10W
(instead of 12) during etching.


The idea was to reach more vertical walls. I know the coil power has an effect
on the passivation film thickness. The platen power drives the ionic
bombardment.


The etching and passivation times were 7.8sec and 7sec respectively. I don't
know if this film could come from the passivation film or from any kind of
contamination.

Does anybody has some idea about that?

Thank you,

Julie