A gas-timing control method for depositing metal oxynitride and transition metal oxynitride (Mx(ON)y) films on glass and flexible substrates using reactive radio frequency magnetron sputtering, without substrate heating. A system includes a sputtering chamber, substrates, targets, three mass flow controllers controlled respective flow rates of argon, nitrogen and oxygen gases alternately and intermittently into the sputtering chamber, and a radio frequency generator with 13.56 MHz which irradiated in the sputtering chamber to decompose sputtering gases. The flow rate ratio of oxygen+nitrogen/argon is at least 0.02, the flow rate ratio of oxygen/nitrogen is at least 0.01, and the sequence timing of argon, nitrogen and oxygen gases alternately or mixed into the sputtering chamber at least 1 sec.