A customized atomic layer deposition (ALD) reactor was designed with components compatible with hydrogen sulfide (H(2)S) chemistry. H(2)S is used as a reactant for the ALD of metal sulfides. The use of H(2)S in an ALD reactor requires special attention to safety issues due to its highly toxic, flammable, and corrosive nature. The reactor was designed with respect to materials compatibility of all wetted components with H(2)S. A customized safety interlock system was developed to shut down the system in the event of toxic gas leakage, power outage, loss of building ventilation or compressed air pressure. ALD of lead sulfide (PbS) and zinc sulfide (ZnS) were demonstrated with no chemical contamination or detectable release of H(2)S.