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!