Case S1: Magnetron Target Positioning
One of the most common arrangements for magnetron sputtering is illustrated in the schematic drawing below: substrates are mounted on a rotating fixture; the sputtering target, with a ring-shaped erosion pattern, is positioned a distance h from the fixture and a distance D off the rotation axis of the fixture.
It is well known that the thickness uniformity on the fixture surface can benefit from tilting the sputtering gun. However, the optimal choice of the 3 positioning parameters, i.e., h, D and
alpha, are not always easy to determine.
With V-Grade 5S, one can explore all the possibilities in virtual experiments and easily discover the positioning parameters that best suit your requirement.
For example, your coating chamber has a rotating fixture of 20-cm in diameter; your source is a silicon target mounted on a 4-inch magnetron cathode that produces an erosion groove measuring 2 inches in diameter. You may want to know what the best thickness uniformity one can achieve for material collection efficiency above 20%, without employing correction masks. In V-Grade 5S, you can call a built-in magnetron source by specifying its erosion groove; you can then position the source and tilt the source to examine both the thickness uniformity and the material collection until you find a satisfying arrangement. For this particular example we find that a thickness uniformity of (+/-) 1.3% and a material collection of 21% can be had with these geometric values:
h = 10 cm;
D = 10.8 cm;
alpha = 18 degrees.
V-Grade 5S also tells you the absolute thickness: for each gram of silicon removed from the target you get a coating of 2858 nanometer on average thickness.
The screenshot below shows the thickness distribution. The three graphs on the right are histograms of vapor incident angle at three different radial positions.
