Correlation between energy deposition and AlN crystal growth induced by ion bombardment

A study has been made of the effects of ion (He, O, N and Ne) bombardment on the crystallization of AlN. AlN0.8 thin films 100 nm thick were deposited on Si(111) wafers by an activated reactive evaporation method in a nitrogen atmosphere. He, O, N and Ne ions were bombarded onto films at room temperature to a dose of 5x1017 ions/cm2, using an energy of 150 keV. This energy was chosen to place the average projected range of the ions in the substrate interior. XRD measurements were carried out using Cu Kα radiation (40 keV, 30 mA). The quantities of energy deposited in the films, through ionization and by recoil atoms, were calculated using TRIM-88. It is concluded that ion bombardment of AlN0.8 thin films causes crystal growth of AlN, with the c-axis oriented perpendicular to the substrate plane, near to room temperature without any thermal annealing. Energy deposition through the ionization plays an essential role in the crystallization of AlN in AlNx thin films. (orig.)