Technical Notes: What is Sputtering?
Sputtering (more formally called sputter deposition) is the removal of material from a solid target by energetic ion bombardment in order to coat a substrate with the sputtered target material.
Sputtering cathodes, such as our TORUS ® Magnetron Sputter Sources, create a low pressure plasma by bombarding an inert gas (typically argon) contained at 1 to 30 millitorr in a vacuum chamber. This process extracts energetic ions which accelerate toward the cathode target, striking it with kinetic energy up to several hundred eV. Energy transfer then ejects material from the target with approximately 90% leaving as neutral atoms and 10% as ions.
Gas phase collisions between target atoms and argon atoms scatter the ejected material into a distributed cloud. As the cloud migrates towards the substrate, the randomized approach angles result in deposition of a uniform film, even on surfaces that have micron-sized vertical structures.
Compared with other thin film deposition techniques (thermal and e-beam evaporation), sputtering has numerous advantages. The high kinetic energy of sputtered atoms gives better film adhesion. Randomized deposition results in improved step coverage. For industrial applications, sputtering can be made a continuous, inline process. Sputtering does not spit lumps of material at the substrate. Although the plasma is energetically 'hot', it has a low thermal capacity and does not heat the substrate. Finally, and most important, sputtering can deposit films of refractory materials, elements, mixtures, and alloys with equal facility.
Unlike evaporation techniques, which require horizontal placement of the crucible containing molten material and vertical placement below the substrate, sputtering works in any orientation, providing it faces the substrate. Each position, sputter-down, sputter-up, and side-sputter, has particular advantages in specific applications.
Applications for Sputter Cathodes:
Industrial
- IR reflective architectural glass
- Anti reflective lenses, lasers
- Visible reflective mirrors, filters
- Hardcoat printheads, machines, tools, turbine blades
- Anti corrosive nuclear fuel rods, marine components, turbine blades
- Impermeable packaging film, moisture barriers
Consumer
- Metallic video disks, hard disks, magnetic storage, compact disks, space blankets
- Decorative bright plastic parts, car 'chrome', jewelry, clothing fibers, plumbing fixtures
- Impermeable packaging film
- Optic flat screen displays, lenses
Microelectronics
- Metallic capacitors, contacts, IC conductors
- Resistive/Insulating IC components, gate barriers
- Optical disk storage
Medical
- Wearcoat prosthetic joints
- Culture surface modification for bacteria growth
- Passivating catheter neutralizing
Scientific
- Heat resistant coating SEM samples
- Ceramic high Tc superconductors
- X-ray focusing x-ray microscopes
Military
- Anti reflective aircraft canopies
- IR transmissive night optics
- Anti damage laser windows.
Learn about our Circular HV or Circular UHV Sputter Sources for R & D
Learn about our Circular Sputter Source Platforms or Circular Cluster Sources for R & D
Learn about our Circular and Linear Sputter Sources for Production Applications
Contact our Process Equipment Division to discuss your specific vacuum application and process equipment needs.