Case 13: Flats in Dome Coater
Here we examine another common job - coating of flat substrates in a dome coater.
In the same model dome coater we introduce a flat substrate which is 7 cm in diameter. Similar to the previous study, we first place the substrate tangential to the dome surface. The resultant coating exhibits a slope distribution with an overall nonuniformity of 0.81%, as shown in the left column of the figure below.
To correct the slope we can pivot the substrate. The best uniformity is found at a pivot angle of approximately 6.8 degrees, which results in an overall nonuniformity of 0.086%, as shown in the right column. The coating is slightly thicker in the middle, as we would expect from the geometry. The larger the flat, the more pronounced this feature becomes.
