Sputtering systems for universities, R&D departments and small batch coating facilities usually look very much alike: cluster tool. And there are many good reasons for this type of design and magnetron arrangement. The major advantage is its flexibility and possibilities to adjust and change the setup on the go.
This enables cluster tools to suit many different and also difficult depositions and coatings with a single system.
Following we will take a closer look into two main components of vacuum chambers with cluster arrangement:
Figure 1: Typical arrangement of circular magnetrons in a cluster system.
1.1. Circular Magnetrons
Problem: Many different applications, coatings, tests to be deposited with limited equipment and budget, while also achieving results that can match industry demands.
Solution: Cluster tool with multiple circular magnetron heads that can be adjusted individually.
A vacuum system with so-called cluster arrangement consists of multiple small size circular magnetron heads, typically in the size of 2” or 3” target diameters, placed confocally above an ideally rotating substrate. The small footprint magnetron head allow 3 or more cathodes in small diameter chamber. The magnetron heads can be adjusted in depth to the chamber via a mounting shaft and a tilting angle is set. With the right axial offset from the middle of rotating substrate, you can achieve uniformity in the <±3 % region.
Figure 2: Calculator for finding good parameters to achieve desired uniformity.