Confocal Cathode Sputtering
An introduction to the confocal method of magnetron sputtering that allows serial and co-sputtering of materials in the production of thin films.
INTRODUCTION
Confocal sputtering is the technique of arranging magnetrons within a vacuum chamber in such a way that multiple materials can be applied onto the substrate without breaking vacuum. Confocal sputtering also allows the user to co-sputter, or to create a film of two or more materials at once. This method is popular for research and development tools and for small scale batch productions.
BENEFITS OF CONFOCAL SPUTTERING
For conventional top down sputtering, only one material will be able to be sputtered at a time. This is because of the geometric relation that the magnetron has with the substrate. Generally when sputtering in this way, the target material must be larger than the substrate to yield acceptable film uniformity. …
One popular method of Physical Vapor Deposition (PVD) is Sputtering, which has numerous product applications. Whereas commercial Sputter systems are often geared to large scale production volume of established processes, there is also a need for smaller scale sputtering systems for research and development where versatility is generally more important than volume throughput. These same smaller sputtering systems can also serve for lower volume initial production.
The Planar Magnetron is, in essence, a classic “diode” mode sputtering cathode with the addition of a permanent magnet array behind the cathode. This magnet array is arranged so that the magnetic field is normal to the electric field in a closed path and forms a boundary “tunnel” which traps electrons near the surface of the target. This electron trapping improves the efficiency of gas ion formation and constrains the discharge plasma, allowing higher current at lower gas pressure and achieves a higher sputter deposition rate for PVD (Physical Vapor Deposition) coatings. …