The structural, morphological and optical properties of cubic MgZnO thin films deposited on sapphire substrates by radio frequency (RF) magnetron sputtering method at different deposition temperatures (RT, 500 degrees C and 800 degrees C) were investigated. The presence of Mg in deposited samples was confirmed through SIMS depth profile. Moreover, Mg content of the alloys was calculated using a quadratic approximation depending on band gap bowing parameter. The film deposited at 500 degrees C with band gap energy of 5.0eV has better crystallinity and atomic homogeneity than the others. Both film quality and Mg atomic distribution deteriorated at 800 degrees C due to thermal effect on the substrate surface. The results explore the applicability of RF-sputtered cubic MgZnO thin films as an active sensor area for deep UV-based optoelectronic applications.