Ions are atoms or groups of atoms that carry a positive or negative electrical charge.
I originally left Hughes Aircraft Research Laboratories for the California Institute of Technology because I wanted to develop that technique. Since 1963, he explains, integrated circuits have been manufactured with electrical connections made of aluminum, an inexpensive material that forms a protective oxide coating. Unfortunately, as integrated circuits become denser and thicker, more power is dissipated and more heat generated. Aluminum has a low melting point. As a material for this industry, it is rapidly approaching the limit of its effectiveness.