>Hi MEMs goup,
>
>I am attempting to fabricate nano-elecrodes.  I make small electrodes with a 30
- 50 nm gap between them, using e-beam lithography and Cr/Au liftoff.  I then
put on large (macroscopic) contact pads using optical image-reversal lithography
with Cr/Au.  When isolated, the nano-electrodes look great.  When I put the big
contact pads on, the tips ALWAYS break back.  What could be the problem???
>
>The most recent samples had a gap in a 2-micron wide wire, which comes off the
large contact pads.  After liftoff, it looked OK but then, later, the 2-micron
wire (and hence the electrodes) was GONE.  There is only a small amound of Cr
residue left!
>
>This has happened repeatedly.  Is this an ESD problem?  I tried only thermal
evaporation for the big pads, to prevent them getting charged up.  I'd really
like to find out what the problem is!  The nano-electrodes are 10 nm Cr + 40 nm
Au.  The large pads are 10 nm Cr + 90 nm Au.
>
>Please offer your suggestons,
>
>Thanks!
>Bill