I have been experiencing some high resistivity problems between gold and
aluminum interlayer. I'm wondering if it's caused by the gold migration or is
there some alloy formed between the two metals? Do I need an adhesion/diffusion
layer between gold and aluminum? If so what would be a good choice? Cr, Ti?

Also, what would be a good way to pattern aluminum lines of 3-4um wide and 2um
spaced, I tried dry etching + wet etching but some of the lines are still
connected at certain points which shorted the circuit. Is lift-off a choice for
patterning such small features for 1um thick of aluminum?

Thanks!