“…In this case, the ionic species in the plasma used for AlN film deposition were surmised to be Ar + (atomic weight: 40), N 2 + (28), and N + ( 14), all attributed to the feed gases, as well as Al + (27), and the species impinging on the substrate during deposition are primarily Ar ions. In general, the densification and structural change of deposited films are attributed to bombardment by energetic ions (∼15 eV at the peak energy of ion energy distribution), 36) so the decrease in surface roughness in the present work is attributed to the impingement of Ar + ions on the substrate. Figure 10 shows the density of the AlN films estimated from the XRR spectra of the AlN films.…”