Double resist structure for electrodeposition bonding

A semiconductor structure comprising:

• a wafer having a wafer outer surface;
• a plurality of copper pillars on a semiconductor chip, the plurality of copper pillars having pillar end portions and pillar outside surfaces;
• a plurality of copper pads on the wafer, the plurality of copper pads having pad end portions aligned with and directly contacting the pillar end portions, the pillar end portions and the pad end portions of the plurality of copper pads defining a plurality of bonding material receiving regions, the plurality of copper pads having pad outside surfaces, at least one of the pillar end portions and the pad end portions being curved;
• and
• a copper bonding layer on the pillar outside surfaces, the pad outside surfaces, the bonding material receiving regions, and portions of the outer surface of the wafer, the portions of the outer surface of the wafer surrounding the plurality of copper pads when viewed in plan.