Growth temperature and N2 ambient pressure-dependent crystalline orientations and band gaps of pulsed laser-deposited AlN/(0001) sapphire thin films

Low temperature growth of c-axis oriented AlN films on γ-LiAlO2 by radio frequency magnetron sputtering

“…And it is observed that the films deposited at lower temperature have smoother surface than those deposited at higher temperatures. When the T s is low, due to the low lateral mobility of the adatoms, the growth of individual crystallites along the surface of substrate is constrained by other crystallite in its vicinity [21], the film tends to be a uniform and fine grain-like texture. When depositing at a higher T s , the growth rate of the grains accelerates with an efficient N atoms supply for the reasons mentioned above; meanwhile, the crystallization of AlN (0 0 0 2) film tends to be improved, because the adatoms with enough kinetic energy on the substrate have more opportunity to move laterally, and the composition of adatoms is more closer to stoichiometric with the increase in N 2 concentration, which lead to a better integrity of lattice and reduce defects.…”