Stress relief and texture formation in aluminium nitride by plasma immersion ionimplantation

Abstract

The effect on the intrinsic stress in AlN films of applying pulsed bias during cathodic arc depositionhas been studied. We find that the stress depends only on the pulse voltage–pulse frequency product,V f. The form of the dependence is well fitted by an exponential function whose parameterscan be interpreted physically. The preferred orientation changes progressively withV f, from hexagonal crystallites having their direction in the plane of the film at lowV f, to hexagonal crystallites having their direction normal to the plane of the film at highV f. The in-plane orientation may be consistent with energy minimization in a biaxial stress fieldwhereas the normal orientation is consistent with the alignment of a channelling direction with the ionbeam.