Thin films of ZnO were grown by metal organic chemical vapor deposition (MOCVD) in a vertical injection rotating disk reactor (RDR) system on sapphire substrates. Kinetics of ZnO growth by MOCVD were studied and an optimal growth window for a RDR tool was determined. Experimental growth conditions were chosen based on calculations of Reynolds Number (Re) and mixed convection parameter in order to select a growth window with stable gas flow and uniform heat transfer. Growth parameters were systemically varied within this window to determine the optimal growth conditions for this MOCVD tool and to study how these parameters affect film growth and quality. Properties of ZnNiO films grown by MOCVD were also studied to determine the effects of Ni incorporation on structural, optical, and magnetic properties.