Influences of arc current on composition and properties of MgO thin films prepared by cathodic vacuum arc deposition

MgO thin films with high optical transmittances (more than 90%) were prepared by cathodic vacuum arc deposition technique. With the increase of arc current from 40 to 80A, the deposition pressure decreases and the film thickness increases; the atomic ratio of Mg/O in MgO thin films (obtained by RBS) increases from 0.97 to 1.17, giving that deposited at 50A most close to the stoichiometric composition of the bulk MgO; the grains of MgO thin films grow gradually as shown in SEM images. XRD patterns show that MgO (110) orientation is predominant for films prepared at the arc currents ranged from 50 to 70A. The MgO (100) orientation is much enhanced and comparable to that of MgO (110) for films prepared at the arc current of 80A. The secondary electron emission coefficient of MgO thin film increases with arc current ranged from 50 to 70A.