In Diode Sputtering, there is no use of magnets and thus, no magnetic field to contain the plasma. This means that plasma ions flow freely throughout the vacuum system and erode almost the entire surface area of the target, increasing target utilization. However, this also means that sputtered film particles are free to move throughout the chamber, not directly to the substrate. This can significantly increase your process time and because there is no electron confinement the substrate will see more heat.
Angstrom Sciences provides diodes for all cathode sizes.