Three dimensional circuit formation

Devices, methods, and systems for forming an electrical circuit out of a conductor embedded in two layers of substrate are disclosed. Portions of the two layers of substrate and the conductor are removed, forming a cavity through the two layers and the conductor. A blocker material is deposited along the wall of the cavity. A portion of the blocker material and adjacent layer of the substrate is removed forming another cavity in contact with a part of the conductor. A surface of the second cavity is then electroless plated by a conductive metal to form part of the electrical circuit.