The ATC ORION 5 UHV Sputtering system is used to deposit thin films of a material onto a surface (a.k.a. “substrate”). By first creating a gaseous plasma and then accelerating the ions from this plasma into some source material (a.k.a. “target”), the source material is eroded by the arriving ions via energy transfer and is ejected in the form of neutral particles – either individual atoms, clusters of atoms or molecules. As these neutral particles are ejected they will travel in a straight line unless they come into contact with something – other particles or a nearby surface. If a “substrate” such as a Si wafer is placed in the path of these ejected particles it will be coated by a thin film of the source material.
The ATC ORION 5 UHV uses a technique called Magnetron Sputtering. The use of Magnetron Sputtering deals with two problematic issues simultaneously: slow deposition rate and the extensive electron bombardment of the substrate, that can cause overheating and structural damage. By using magnets behind a cathode to trap the free electrons in a magnetic field directly above the target surface, these electrons are not free to bombard the substrate to the same extent as with diode sputtering. At the same time the extensive, circuitous path carved by these same electrons when trapped in the magnetic field, enhances their probability of ionizing a neutral gas molecule by several orders of magnitude. This increase in available ions significantly increases the rate at which target material is eroded and subsequently deposited onto the subtrate.