Hello Dau,

I expect the root cause of the Al wire to be caused by ion bombardment.
Fluorine based chemistries do not etch Al.I don't know your process
parameters nor the reactor  you are using but if it is a RI reactor it
means you are using a fair large amount of bottom power. This bottom
power is the major driving factor for the ion bombardment. I also wonder
if you have resist that is covering your Al lines. If that is the case
you could also try a process that consumes less resist.
The longer the resist remains on the wafer the shorter the Al will be
drectly exposed to the plasma.



Best regards,

Marc V.C.