Rakesh,
   You are probably getting some sputtering of the platinum.  Turn down
your power and/or boost the pressure to reduce the kinetic energy of the
ions.

-Mike Martin
 U. of Louisville


>>> rakesh babu  11/29/2006 12:19 PM >>>
Folks,

  I was trying to etch 18um parylene using O2 plasma
with Al as the mask and after 2 hrs of etching i found
some black residue which could only be removed by
using a swab. Can anyone please tell me the reason for
this . The metal under parylene was Platinum.