Wet etch strip of Ti/Al/Ni/Au stack

Hi SNF people,

I would like to strip a metal stack of Ti/Al/Ni/Au with a wet etching recipe, but I'm not too sure what chemicals would be best suitable.

My original thought was to remove the Au, Ni, and Al layers with aqua regia solution, and then remove the Ti layer with dilute HF, but I am not sure if this will work.

Does anyone with experience have any better ideas?

Thanks,

Vijay Parameshwaran
vijayp@stanford.edu