What is Sputtering?

Guest post is provided by Denton Vacuum, LLC. Denton Vacuum manufactures machines that employ precision thermal evaporation methods for diamond-like film quality. Visit www.dentonvacuum.com for more information.

Sputtering systems come in different forms, including magnetron sputtering, e-beam evaporation and reactive sputtering. The goal of sputtering is to lay very thin layers of metal or other substances onto a specific material. These layers are very, very thin and can be as small as a few nanometers. Sometimes the layers are so thin that you have to use an electron microscope to see them. Applications for sputtering include semiconductor fabrication, medical devices, and emerging technologies. These layers are so hard that they are compared to the strength and durability of a pure carbon diamond.  These attributes are useful when the target material being coated is going to be subjected by much abuse from heat, pressure or potential chipping.

In any sputtering system, be it a thermal evaporation system or anything else, the gas in the chamber is heated so hot, that it turns to a state of plasma. To give you an idea of how hot this is, it means it’s no longer a gas and has to be classified as something else. Plasma is what is found in the core of our sun. Heating the layering material to this temperature ionizes the electrons attached to their atoms, causing the material to break apart into a sort of mist. This mist condenses on the target material, leaving a coating that can be only atoms thick. This wouldn’t be possible with any other method and creates an evenly distributed, dense coating on the object.

A common application for this method is for optical coating systems. Microscope lenses can be scratched and need coating to protect them. Scientific studies on specimens prone to ionization find this protection particularly necessary, and protect the experiment from added variables.