Ni etching?

Hi labmembers,

I have some wafers with 40nm Ni on top of 500nm Al. I'd like to etch the 40nm Ni layer while preserving the 500nm Al. I'm open to either wet or dry etching. Does anyone have any experience etching Ni? I'd like the selectivity between Ni and Al to be as high as possible, but it doesn't need to be super high. Any suggestions/experience would be appreciated.

Thanks for your help!

Azadeh

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Azadeh Moini
Stanford University
Department of Electrical Engineering
amoini@stanford.edu