Variation of crystallization with arrival ratio in titanium nitride films formed by dynamic mixing method

Abstract

The preferred orientation of titanium nitride films with cubic structure produced at about 400 °C by the dynamic mixing method is studied in the range of the arrival ratio Ti/N from 1.0 to 2.6 and in the case of normal incidence of nitrogen ion beam to the substrate surface. The accelerating voltage of nitrogen ions is 30 kV. The current density of nitrogen ions, in which the numerical ratio of atomic to molecular ions is about unity, is kept at a constant, 0.18 mA/cm 2, and the deposition rate of titanium is changed. The composition ratio of titanium to nitrogen in the prepared films are roughly unity, in spite of the large difference of the arrival ratio. The preferred orientation varies from the 〈111〉 axis normal to the surface to the 〈100〉 axis normal as decreasing the arrival ratio, though the film prepared with Ti/N = 1.0 includes a small amount of crystals with the 〈111〉 and 〈110〉 axes as the surface normal and amorphous part. Such a variation of the crystallization is considered to arise by the difference in the energy deposition per a titanium atom.