English: Classification of temporal (A, top) and spatial (B, bottom) ALD reactor systems based on distribution and flow direction of the reactants. Flow-type reactors for temporal ALD include the cross-flow (flow-channel or travelling-wave, A.1), radial-flow channel reactor (A.2), perpendicular-flow reactors based on top-injection (utilizing a showerhead in A.3 or a vortex funnel in A.4 for distribution of the gaseous reactants). Several process variants for productivity increase (batch-wafer reactor in A.5, based on cross-flow reactor) and for particles/powders processing (flow-through reactor in A.6 and fluidized bed reactor in A.7 reactors) are shown. A carousel reactor (B.1) and a roll-to-roll reactor (B.2) for spatial ALD are also illustrated.