We proposed a method to enhance the characteristics of undoped ZnO films byH2post-treatment using photochemical vapor deposition. The resistivity of aH2-treated film decreased from1×10−2to2×10−3 &OHgr; cm,the haze ratio increased from 37&percent; to 48&percent;, and no degradation of total transmittance was observed. There are two possible explanations for these phenomena. First, hydrogen atoms assist the desorption of oxygen atoms from the film, resulting in decreased resistivity. Second, hydrogen atoms etch small grains growing among large ones on the surface of the film, resulting in a rough surface. ©1997 American Institute of Physics.