Growth of preferentially-oriented AlN films on amorphous substrate by pulsed laser deposition

Preferentially-oriented aluminum nitride (AlN) films are grown directly on natively-oxidized Si (100) substrate by pulsed laser deposition (PLD) in nitrogen (N₂) environment. The AlN preferential orientation changes from (002) to (100) with increasing N₂ pressure. Such different behaviors are discussed in terms of deposition-rate-dependent preferential orientation, kinetic energy of depositing species and confinement of laser plume. Finally, sample deposited at 0.9 Pa is proved to have the highest (002) peak intensity, the lowest FWHM value, the highest deposition rate and a relatively low RMS roughness (1.138 nm), showing the optimal growth condition for c-axis-oriented AlN growth at this N₂ pressure.