3. Fluid dynamics and SALD: engineering challenges

From a chemical point of view, SALD is equivalent to ALD and, in order for deposition to occur only through surface-limited layer growth, the surface to be coated must be saturated and any physisorbed precursor in excess or remaining above the surface must be removed in the purge zone. Since, by the very principle of the SALD method, precursors are supplied continuously, their efficient separation is a key issue, and reactors must be designed in such a way that the inert flow barrier is effective. As discussed in § 2