Physical Vapor Deposition

Sputtering is a physical vapor deposition (PVD) process used to apply extremely thin films of one material onto another.  The use of PVD for thin film deposition is common across many industries ranging from the deposition of magnetic media on hard disks for disk drives, to the manufacture of exacting semiconductor IC chips, to food packaging and practically everything in between.  Industrial uses of magnetron sputtering include the coating of drills and cutting tools in the machining industry, increasing performance and longevity, as well as the deposition of various thin films on architectural glass windows to enhance thermal, reflectivity and aesthetic properties.  The aerospace industry uses magnetron sputtering to deposit thin films on turbine blades and mirror surfaces for missile guidance systems. Magnetron sputtering also is used to deposit thin films on plastic packaging in the food industry, to enhance the attractiveness of the packaging, while improving the protection provided to the product contained within. 

The process occurs inside a vacuum chamber that contains a magnetron, a cathode, an anode, a target, a substrate and an inert gas. The chamber is first evacuated and backfilled with the inert gas, usually argon. When a potential is placed across the electrodes, electrons from the cathode strike the Ar gas atoms, stripping them of more electrons and creating Ar+ ions. The Ar+ ions are attracted to the negatively charged cathode, colliding with the surface of the cathode. These collisions impart energy to cathode atoms, ejecting them into the evacuated chamber, where they deposit on the substrate. Because these atomic collisions result in erosion of the target (cathode) it is made with a replaceable plate of the material being deposited.  To increase the sputtering rate, a magnetron is placed beneath the target to trap elections above the target, improving frequency of argon gas collisions.  The magnetic field above the target is often referred to as an electron tunnel.

Many factors influence the quality of a sputtered film; the magnetron is only one of them.  Gas pressure and power are the two most important factors in sputtering.  Pressure ultimately determines the properties of the sputtered film by controlling substrate temperature, sputtered atom energy, self-sputtering, deposition rate, film microstructure, and stress in the film.  Power in the system ultimately dictates the sputter rate and the temperature of the substrate.  System geometry (e.g. distance of substrate from target) affects the deposition rate. 

We've been helping customers improve their sputtering processes for many years and have found each system unique because of all the factors mentioned above.  We have tackled problems like better target utilization, as well as more uniform deposited films, and the containment of plasma when thicker or ferrous targets are utilized.  Please contact us with your requirements so we can begin the process of working with you to achieve your goals.

For further inquiries, please e-mail us at info@dextermag.com -or- call us at:  800-345-4082 (In North America) or +44 (0) 1189 602430 (In Europe).