Comparing Magnetron Sputtered ScN Films Grown on Sapphire (10-10) and (1-102) Substrates*

ScN films with high quality crystal structure and desirable carrier concentration have previously been grown on sapphire (0001) substrates. This study seeks to determine whether similarly high quality films can be grown on (10-10) and (1-102) orientated sapphire. The depositions for this study were carried out via reactive, unbalanced, DC magnetron sputtering. Previous growth of ScN on sapphire (0001) showed film quality is sensitive to sputtering conditions. This study seeks to determine what, if any, sputtering conditions can produce films of comparable quality to those grown on sapphire (0001) substrates on the lower symmetry surfaces. The impact of these growth conditions on the crystal quality and electrical properties were evaluated using x-ray diffraction and Hall-effect measurements. X-ray diffraction results indicate that growth on sapphire (1-102) is sensitive to temperature, with optimal growth occurring in a 40°C window. For (10-10) sapphire, similar crystal quality occurs over temperatures from 500-900°C. XRD also shows no conditions tested for either substrate displayed the single crystal growth present on (0001) sapphire.