In situations when the deposition of a coating is performed at a curved surface or at a large substrate, layer thicknesses are not uniform anymore: thicknesses of deposited layers may vary with varying distance from the substrate center. In many cases it is necessary to design a coating with lower sensitivity to this factor. Another possible situation is connected with mass-production of samples in a chamber, where the deposition conditions at different positions are different.
Since our Environment manager allows to define up to 32 different environments, it is possible to specify rather detailed Taper Function dependencies. For example, we can define 5 environments with different taper coefficients for H and L-index materials (see picture below).
Taper coefficients specified for each environment are ratios of the thicknesses at this position to thicknesses of the theoretical design. These ratios could be different for each layer material. If Taper coefficients at some position are equal to 1.0, it means that thicknesses are equal to thicknesses of the theoretical design.