Electroplating nano-bicrystal and non-nano-bicrystal copper features

Nano-bicrystal copper and non-nano-bicrystal copper may be electroplated to form a mixed crystal structure, such as a two-in-one copper via and RDL () structure or a two-in-one copper via and pillar structure. Nanometer bicrystal copper can be electroplated on the non-nanometer bicrystal copper layer by pretreating the surface of the non-nanometer bicrystal copper layer with an oxidizing agent or other chemical agent. Alternatively, nano-bicrystal copper may be electroplated to partially fill the recess in the dielectric layer, and non-nano-bicrystal copper may be electroplated over the nano-bicrystal copper to fill the recess. The copper capping layer may then be removed. 可电镀纳米双晶铜和非纳米双晶铜以形成混合晶体结构，例如二合一铜通孔与RDL()结构或二合一铜通孔与柱结构。通过用氧化剂或其他化学试剂预处理非纳米双晶铜层的表面，可以在非纳米双晶铜层上电镀纳米双晶铜。替代地，可电镀纳米双晶铜以部分地填充介电层中的凹部，并可在纳米双晶铜上方电镀非纳米双晶铜以填充凹部。随后可去除铜覆盖层。