An alpha particle blocking structure and method of making the structure. The structure includes: a semiconductor substrate; a set of interlevel dielectric layers stacked from a lowermost interlevel dielectric layer closest to the substrate to a uppermost interlevel dielectric layer furthest from the substrate, each interlevel dielectric layer of the set of interlevel dielectric layers including electrically conductive wires, top surfaces of the wires substantially coplanar with top surfaces of corresponding interlevel dielectric layers; an electrically conductive terminal pad contacting a wire pad of the uppermost interlevel dielectric layer; an electrically conductive plating base layer contacting a top surface of the terminal pad; and a copper block on the plating base layer.