Magnetron sputtering target for magnetic materials

The magnets may be coated with suitable materials such as the target material or a non-contaminating material with the deposited film. Since the surface of the magnets erode little and may be coated, no-contaminating materials are deposited on the substrate.

Since the permanent magnet circuit is located on the surface of the target and is directly exposed to the plasma rather than through the thick target, the required permanent magnets are smaller and less expensive than those mounted on the back of the target.

The smaller magnets make it possible to design suitable erosion patterns. The magnetic circuit design is simpler with surface-mounted permanent magnets.

The erosion profiles become wider, rather than deeper rings, so that the utilization of the target is enhanced and the life of the target is increased.

The permanent magnets are held on target by their own magnetic force, or they can be bonded on the target. They can also be held on mechanically or by a combination of methods.

My innovative target assembly does not limit the thickness of the target and it provides better target-cooling capability.

A non-planar, machined surface of the target (FIG. 7) may be used for a variety of applications.

The small erosion areas produced are ideal for very small targets.

Electrical connections are easier and an ideal power feeding system can be designed.

During deposition, the large amount of heat associated with the plasma driving power can be removed effectively with the new invention. There is no limitation on the thickness of the target assembly, including the water jacket since the thickness does not hinder the magnetic field strength on the target.

Better magnetic circuit design provides better deposition uniformity and better erosion profile of the target without the need for rotating magnets. The stationary magnetic source provides a stable plasma with no abnormal arc discharge.

The rotated magnets in the conventional target work as a magnetic break which requires a high power motor causing target heating. Without the rotating magnets, plasma power feeding and target cooling design can be idealized. Better cooling design makes it easier to remove heat from the target.

Fine erosion patterns can be achieved with small magnets so that the uniformity of the deposited film and utilization of the target are greatly improved. The precisely aligned magnets provide uniform magnetic flux over the entire erosion area, as opposed to the magnetic pole pieces. These pole pieces can be effectively used only with the simplest erosion patterns are acceptable. These pole pieces with the complex patterns distribute the magnetic flux unevenly. The fine patterned erosion areas in my innovative design make it possible to reduce the distance between the target and the substrate. This leads to a higher deposition rate with more material deposited on the substrate and less on the chamber walls.

A non-magnetic target may be used by laminating it to a magnetic backing plate.