Hello,
I am currently facing a problem with gold pads deposited on a tungsten layer.
My gold pads are deposited by sputtering and patterned by lift off.
When a gold wire contacts the pad, the pad-wire bonding is stronger than the
tungsten-pad bonding and then the pad is removed.
On one hand, I read papers where they assume this problem can come from the
creation of a thin tungsten oxide layer which avoid a stronger bonding. Then the
idea would be to etch tungsten a bit just before depositing gold. Do you think
it is right?
On the other, friends of mine faced a similar problem but with Silicon instead
of Tungsten. They used a chrome layer in between Gold and Si (SiO2) and it
worked. I cannot find any information about this for the moment... So, do you
think it could work? (or do you know where I could find information?)
Hope one of you will have an idea or at least will give me his/her opinion.
Thank you,
BOUGRINE Guillaume