Depth profiles in nitrogen implanted Si xAl y coatings post-implanted with oxygen

Abstract

“Sialons” are phases in the Si–Al–O–N and related systems based on the (Si, Al)(O, N) 4 tetrahedral structure. They have several interesting mechanical, thermal and chemical properties to make them candidates for high temperature applications. Thin Si–Al–O–N layers (200 nm) were synthesized using nitrogen and oxygen implantation into Si 33Al 67, Si 45Al 55 and Si 63Al 37 thin films deposited by d.c. magnetron sputtering on glassy carbon substrates. Nitrogen has been first implanted at 50 and 20 keV, then oxygen was post-implanted at 50 keV with doses ranging from 1 to 10×10 17 ions cm −2. High depth resolution profiles and stoichiometry have been obtained using Rutherford backscattering spectrometry and resonant nuclear reaction analysis. The chemical bonds have also been investigated using low energy electron induced X-ray spectrometry. Analysis of the results shows that the nitrogen concentration decrease when oxygen is post-implanted. Chemical bond analysis indicates the presence of a solid solution containing Si, SiO 2, Si 3N 4, Al, Al 2O 3 and AlN. The percentage of these compounds are correlated with the heat of formation.