Essential Basics of Magnetron Sputtering In PVD Coatings

The Planar Magnetron is a classic “diode” Essential mode sputtering cathode with the key addition of a permanent magnet array behind the cathode.

This magnet array is arranged so that the magnetic field on the face of the target is normal to the electric field in a closed path and forms a boundary “tunnel” which traps electrons near the surface of the target.

Several different:

Magnetron cathode/target shapes have been us, but the most common are circular and rectangular.

Rectangular Magnetrons are most often found in larger scale “in line” systems where substrates scan linearly past the targets on some form of conveyor lt or carrier. Circular Magnetrons are more commonly found in smaller scale “confocal” batch systems or single wafer stations in cluster Essential tools.

Although more complex patterns can done, most cathodes – including virtually all circular and rectangular ones – have a simple concentric magnet pattern with the center ing one pole and the perimeter the opposite.

For the circular Magnetron Essential:

This would be a relatively small round magnet in the center, and an annular ring magnet of the opposite polarity around the outside with a gap in between.

For the rectangular Magnetron the center one is normally a bar down the long axis (but less than the full length) with a rectangular “fence” of the opposite polarity all the way around it with a gap in between. The gap is where the plasma will be, a circular ring in the circular Magnetron or an elongated “race track” in the rectangular. Note that, especially in larger cathodes, the magnets can be several individual segments rather than one solid piece.

As it is using in PVD and Essential sputters off:

You will be able to see these characteristic erosion patterns on the target face. In fact, in the event of any magnet problems such as missing, misaligned, or upside down, the erosion path will be abnormal and this can be a good diagnostic indication of such problems within your Essential cathode.

In such cases Essential:

It therefore becomes necessary to take appropriate steps to avoid corrosion of either the magnets or the pole plate. Pole plates can fabricat from magnetic alloys of stainless. Steel, for instance, to avoid corrosion, and magnets. Which depending on their could otherwise affect. Exposure to water can encapsulate in plastic or epoxy.

Planar Magnetrons, and their close cousins the clamp-on inset target Magnetrons. Allow the user to achieve higher sputter deposition rates.

A wide variety of such:

Cathodes and targets are commercially available. Including various options for magnet strength and layout to enhance particular. Essential Aspects of the process when needed. They have become a mainstay of Magnetron PVD Sputter processing.

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