Texture development in IBAD MgO films as a function of deposition thickness and rate

We have examined the effect of film thickness on in-plane texture for ion-beam assisted deposition (IBAD) of MgO films. Plan-view dark-field transmission electron microscopy (TEM) has revealed that texture develops rapidly, reaching its best value at a critical thickness of~10 nm. These results have been confirmed by quantifying the in-plane texture of these samples at each thickness with X-ray diffraction φ-scans. We have also examined the effects of variable deposition rate on texture formation. X-ray diffraction shows that the optimum in-plane texture is achieved at the critical thickness with a rate of 0.2 nm/s. However, TEM imaging has shown that the distribution of well-aligned grains decreases with an increase in rate. As such, deposition at 0.1 nm/s was found to be sufficient for achieving good in-plane distribution values and good surface coverage for subsequent depositions. By combining the results of both of these experiments, we were then able to optimize our deposition process and apply them to the growth of IBAD MgO on metal substrates