copper-copper bonding process simplifies

1. A method of bonding a first copper element onto a second copper element having a step of forming a crystalline layer of copper-enriched oxygen on each of the surfaces of each of the first and second members whereby the elements will contact, the total thickness of the two layers being less than 6 nm, said step comprising: a) at least one step surface polishing so as to obtain a roughness of less than 1 nm RMS, and hydrophilic surfaces; b) at least one of said surface cleaning step to remove the presence of particles due to polishing and most of the corrosion inhibitors; c) a contacting step of the two crystal layers of copper-enriched oxygen