Highly textured hexagonal AlN films deposited at low temperature by reactive cathodic sputtering

All AlN films deposited from 300 to 700°C on silica, Si(100) and Si(111) substrates exhibit (00.2) and (10.1) preferential orientations. We obtain the highest degree of preferential alignment of the (0001) planes of AlN on silica substrates reported to date for a deposition temperature of 350°C. In this 'low' temperature range, the multiple of random density values (mrd-values) have a low dependence on the nature and orientation of the substrates. At 700°C, we obtain a mrd-value of 165 on Si(111) with additionally a significant in plane orientation. As T increases in this 'mean' temperature range (> 350°C), crystalline substrates, then the fit of the symmetry of the substrate surface with that of the growing film gives increasing mrd-values.