An alternative reactive sputtering from SrCuO2 and NaCuO2 targets was adopted for a synthesis of an infinite-layer Sr1-xNaxCuO2 film. In a microwave cavity reactive oxygen gas was activated and generated much radicals O*. The substrate temperature range for the crystallization of the tetragonal phase was enlarged by using radicals O*. The tetragonal finite-layer SrCuO2 film showed the phase with the comparatively large c parameter. The infinite-layer structure with the small c parameter was the dominant tetragonal phase in the Sr1-xNaxCuO2 films. The analysis by XRD patterns showed that substitutions of Na atoms increased defects of oxygen in CuO2 layers and resulted in a Sr-poor composition. It was confirmed that activated oxygen gas by microwave promotes more oxidation reactions during a him deposition than non-activated oxygen gas.