Effect of oxygen plasma treatment on the properties of ALD hafnium oxide films

Abstract

In this work, we studied the effect of processing hafnium oxide samples prepared by atomic layer deposition in a gas discharge plasma of a mixture of argon and oxygen in a ratio of 1:10. It has been shown that such treatment preserves the amorphous structure of the film and reduces the content of oxygen vacancies in the film. This is important for the use of the film in the gate dielectric of a transistor. Processing in plasma leads to a change in its properties, namely: an increase in density and refractive index, as well as a decrease in the intensity of emission bands that are associated with an oxygen vacancy. The plasma temperature and ion energy were determined from the argon emission spectra. The activation energy for the diffusion of oxygen ions in hafnium oxide films has been calculated to be 0.43 eV.