However, it is unclear if position 20 still corresponds to the TCS or if it is measured on an unpolished part of the sample. Another way to estimate the TCS angle is to consider that from positions 10 to 11 the Ge3d state is not detected anymore. So, there is at least a GaInP thickness of 6.3 nm, according to the discussion above, between the measured point (position 11) and the buried interface. For this sample, the step width was 75 µm between each position. On the TCS, the interface is at position 8, i.e. 225 µm away from position 11. This corresponds to a tapering angle of 0.002°. In both cases, it is evidenced that the TCS angle is low, even lower than the 0.02° accuracy that the MULTIPREP TM can provide, and it might explain why reproducing such an angle is challenging from an experimental point of view.