Undoped ZnO films were fabricated by a MOCVD method with DEZ and $H2_O$ as source materials. By changing the substrate temperature and the mole ratio of DEZ and $H2_O$, resistivity and surface texture could be effectively controlled. The surface texture and the resistivity has close relationship. The film with the lower resistivity has the higher haze ratio. Lowering the partial pressure and controlling substrate temperature, low resistive undoped ZnO film was obtained. When DEZ/$H_2O$=2, and substrate temperature 170℃, the obtained value was resistivity of $1\times10^{-2}$ Ω ㎝, haze ratio of 20%, and transmittance at 550nm of 86%. For the application of the film to the electrode of amorphous silicon solar cells, the improvement of the resistivity and surface texture was essential. A new approach, post hydrogen treatment, to increasing conductivity and surface roughness of ZnO films has been developed in this study. The hydrogen treatment of the ZnO film using photo- CVD was performed with the treatment time as a variable. And as a result, the electrical characteristics were saturated beyond 30 minutes and haze ratio still increased thereafter. Obtained characteristics are as follows; the resistivity was lowered to $2\times10^{-3}$ Ω ㎝, and haze ratio increased to 47.7%, and transmittance not changed. Moreover, undoped ZnO films were fabricated by photo- MOCVD method. The observed characteristics shows the UV irradiation may cause oxygen deficiency. This fact was deduced from decrease of resistivity and deposition rate. Especially the obtained resistivity is $1\times10^{-3}$ Ω ㎝, one order enhanced value. The results of the hydrogen treatment and photo- MOCVD imply the possibility of application of the undoped ZnO to the electrodes of a-Si solar cells.
