A CVD reactor for single sided deposition of material on substrates, may comprise: an upper gas manifold and a lower gas manifold; a substrate carrier comprising a gas tight rectangular box open on upper and lower surfaces, a multiplicity of planar walls across the width of the box, the walls being equally spaced in a row facing each other and defining a row of channels within the box, the walls comprising mounting fixtures for a plurality of substrates and at least one electrically resistive heater element; and clamps within the vacuum chamber for making electrical contact to the at least one electrically resistive heater element; wherein the upper gas manifold and the lower gas manifold are configured to attach to the upper and lower surfaces of the substrate carrier, respectively, connect with upper and lower ends of the channels, and isolate gas flows in odd numbered channels from gas flows in even numbered channels, wherein the channels are numbered in order along the row, and wherein the gas flows comprise, for each of the gas manifolds, an exhaust gas flow and a process gas flow.