The influence of the deposition angle on the composition of reactively sputtered thin films

We have performed computer simulations and experimental studies of the compositional behaviour of reactively sputter-deposited films as a function of the deposition angle. The composition of deposited films is essentially determined by the supply rate of both sputtered material and reactive gas atoms to the substrate surface. The sputtered flux distribution has a preferential direction away from the target while the reactive gas flux distribution atoms is primarily isotropic in the deposition chamber. The supply of sputtered material to the substrate surface is therefore angular dependent while the supply of reactive species is not. The film composition is consequently angular dependent. Our findings show that the film has a higher content of the stoichiometric compound for higher deposition angles. (C) 1997 Elsevier Science S.A.