A proximity heads for dispensing reactants and purging gas to deposit a thin film by Atomic Layer Deposition (ALD) includes a plurality of sides. Extending over a portion of the substrate region and being spaced apart from the portion of the substrate region when present, the proximity head is rotatable so as to place each side in a direction of the substrate region, and is disposed in a vacuum chamber coupled to a carrier gas source to sustain a pressure for the proximity head during operation. Each side of the proximity head includes a gas conduit through which the reactant gas and the purging gas are sequentially dispensed, and at least two separate vacuum conduits on each side of the gas conduit to pull excess reactant gas, purging gas, or deposition byproducts from a reaction volume between a surface of the proximity head facing the substrate and the substrate.