I have a problem with the adhesion of AZ40XT photoresist on the seed layer. I deposited 100 nm titanium on the silicon as a seed layer, and then coated AZ40XT photoresist with a thickness of 100 µm. After development, the exposed PR was removed and the seed layer on the bottom was exposed. During the electroplating, the plating solution can infiltrate the resist film undercutting it. This is because of the poor adhesion between the AZ 40XT photoresist and the seed layer.
The seed layer I need should be conductive (for electroplating) and has strong adhesion with AZ40XT. Any suggestions to improve the adhesion between AZ40xt photoresist and conductive metal? Any adhesion promoter recommendation?