Effect of N+2 ion bombardment on the compositional change and residual stress of AlN film synthesized by ion beam assisted deposition

Abstract

The compositional change and residual stress of aluminum nitride film synthesized by ion-assisted evaporation and sputtering are discussed in terms of ion bombardment. In the growth of AlN film, N+2 ion bombardment could increase the N incorporation probability and reduce oxygen impurities. The stoichiometric nitride was obtained at an arrival ratio of N/Al higher than 1.5. With increasing ion flux and energy the residual stress shows a tendency to shift from tensile to compressive stress. Except for the low region of ion flux and energy, the compressive stress shows a linear proportionality to the momentum parameter of incident ions defined as the product of ion flux and (ion energy)1/2 in the ion beam assisted deposition process. The temperature dependence of residual stress is also discussed.