In a method for manufacturing a metallic-channel device, a metallic layer is formed on a substrate. The metallic layer is formed by an atomic layer deposition technique and has a first thickness. An insulating layer is formed over the metallic layer. A gate contact layer is formed over the insulating layer. The formed layers are processed to remove the gate contact layer, the insulating layer, and a portion of the metallic layer from a source-drain region. A remaining portion of the metallic layer on the source-drain region has a second thickness that is smaller than the first thickness. Source and drain metal contacts are formed over the remaining portion of the metallic layer.