Determination of the interdiffusion coefficient for Si/Al multilayers by Auger electron spectroscopical sputter depth profiling

摘要

Initial stage interdiffusion processes in Si/Al multilayer structures were studied quantitatively by means of Auger electros spectroscopical sputter depth profiling. The Al sublayers and the Si sublayers were sputter deposited onto a Si(111) substrate. The initial stage of the interdiffusion at the location of the Si/Al interfaces was induced by heating the specimens isothermally in an argon atmosphere at 150, 165 and 180℃ for 20 min, and at 165℃, additionally, for 10 and 30 min. It was found that, in such sputtering prepared multilayer structures, interdiffusion across interfaces near the surface of the multilayer is faster than across interfaces in the deeper part of the layer. Measured depth profiles of the annealed specimens were compared with that of the as-deposited specimen after quantitative evaluation according to the so-called MRI (mixing-roughness-information depth)-model. As a result, values of the interdiffusion coefficient as a function of the depth beneath the surface were obtained.