Quantitative Sputter Depth Profiling of Silicon- and Aluminium Oxynitride Films

 Silicon- and aluminium oxynitride films have gained attention because of their interesting properties in various fields of technology. The specific properties strongly depend on the concentration of oxygen and nitrogen in the films. For the quantitative analysis of homogeneous silicon- and aluminium oxynitride films, EPMA has been proven a very reliable and precise method of analysis. In order to characterise films with graded composition or interface effects between the film and the substrate it is necessary to use sputter depth profiling techniques such as SIMS, hf-SNMS, AES, or hf-GD-OES. Unfortunately, stoichiometric silicon- and aluminium oxynitride films are insulating and therefore charge compensation has to be applied. For the quantification it was necessary to prepare calibration samples which have been analysed by different bulk analytical techniques such as NRA, RBS and EPMA. With these calibration samples, sensitivity factors have been determined and the functional dependence of the sensitivity factors on the composition has been derived. The advantages and disadvantages of the different sputtering techniques and the applicability of the obtained sensitivity functions for the quantitative depth profiling of silicon- and aluminium oxynitride films are discussed.