Introduction

The shape of the sputtering target plays a significant role in sputtering. Depending on the shape, sputtering targets are usually available in planar and rotatory categories. Planar targets can be rectangles or circles, and rotatory targets are cylindrical. The quality of deposition, efficiency, and overall performance of sputtering depend on the shape of the target. Overall, this article details different shapes of sputtering targets and their advantages and disadvantages.

Different Shapes of Sputtering Targets

1. Planar Sputtering Targets:

Planar targets have a simple structure. The most common shapes available in the market are rectangular and circular, as they can be easily molded. In short, preparing planar targets requires minimum machine and technological requirements. Thus, planar targets are in enormous demand in the market.

Dimensions of Planar targets:

Aspect	Round	Rectangular
Size	The diameter of the target is around 50.38-388mm.	The length and width of the rectangular target are 1700 and 381 mm, respectively.
Thickness	The thickness of the target is 15mm.	It’s the same as that of the round target.

Advantages and disadvantages of planar sputtering targets:

The following are some of the advantages and disadvantages of planar sputtering targets:

Advantages	Disadvantages
The planar price is low as the molding process and structure are simple.	The utilization rate is very low.
The planar targets have strong versatility. They cannot be damaged easily during transportation.	The process makes the target body thinner.
Film layers sputtered by planar targets usually boast good uniformity and repeatability.	The target cannot be used after a certain pitch depth.

2. Rotatory Sputtering Target:

The rotatory sputtering target uses more material and energy than the planar target. Thus, it reduces the system’s downtime and offers longer production time. In rotatory targets, heat spreads out evenly over the target’s surface, allowing the use of higher power densities. Therefore, besides the improved performance, the deposition speed is increased.

Although, the rotary sputtering target is mainly used in thin film deposition to coat large areas. The typical manufacturing methods include plasma spraying onto the base tubes, casting, and extrusion of the entire assembly.

Sample size:

Aspects	Details
Length	The target produced by plasma spraying has a length of 3000mm.
Size	φ56~190mm L: 120~5000 mm.
Relative density	>99% Purity: >99.5%≥99.999%.

Advantages of Rotatory Sputtering Target:

The surface area of rotatory targets is more significant for the given length. Thus, the power of the magnetron sputtering is spread over a large area. This allows the target to stay cool and reduces the formation of nodules and arcing.
Its complex structure allows longer runtimes.
Compared to planar targets, rotatory targets have a higher rate of utilization.

3. Cylindrical Planar Sputtering Target

The cylindrical planar sputtering target works on the principle of the rectangular planar magnetron target. It combines the best of planar rectangular targets and coaxial cylindrical targets. Further, it offers uniformity and high target utilization.

Advantages of Cylindrical planar sputtering target:

The cylindrical, planar magnetic sputtering targets preserve the uniformity of the rectangular planar target coating and maximize the target’s utilization rate.

At a specific annular pit depth, the target’s core can rotate relative to the target tube, utilizing the unused area of the target tube.

When the cylindrical target core rotates, the target’s surface sputters uniformly, preventing the formation of pits. Here, the target utilization reaches 50-60%.

Cylindrical planar sputtering targets outperform traditional planar and rotating targets. Moreover, manufacturers are likely to introduce even more advantageous target shapes, highlighting the vast and evolving potential of the target market.

Applications

The target shapes provide the desired coating thickness and uniformity along the substrate.
The tubular targets increase material usage, decrease waste, and be cost-effective.
The target geometry can improve the heat dissipation during the sputtering process.
Rectangular targets serve industries like solar energy and electronics because they easily scale for large-area coatings.
The geometry of the sputtering target affects plasma distribution and ionization efficiency, enhancing the overall sputtering rate and deposition uniformity.

Conclusion

In summary, the geometry of sputtering targets plays a very significant role in determining the efficiency and effectiveness of sputtering. Each of the two types of sputtering targets has a very different set of advantages and disadvantages. Simplicity and economy make planar targets more viable, while rotatory provides better performance and deposition speeds. The cylindrical, planar sputtering target is an essential advancement because it incorporates both merits with a view toward increased uniformity and improved target use. Expectingly, new target shapes would continue evolving as research and technology continued. Furthermore, this would open up possibilities for thin film deposition, driving applications in a variety of fields and would further enrich the sputtering market.