Ion beam analysis using micro-Rutherford back-scattering spectrometry was used to investigate the interaction between Ge and Ir in a lateral diffusion couple. Optical microscopy, scanning electron microscopy and atomic force microscopy were also used. When samples of Ge islands on Ir films were annealed between 600 to 800C, substantial lateral diffusion was observed, resulting in a number of reaction regions. Micro-Rutherford back-scattering analysis indicated that the phase Ir3Ge7 stretched across the original island interface at all temperatures, with the phase Ir4Ge5 forming in the reaction region with unreacted Ir. The IrGe4 phase was observed to nucleate in the middle of the island at above 800C. Depth information was readily obtainable from micro-Rutherford back-scattering spectrometry, which was used in conjunction with atomic force microscopy data to estimate the densities of the phases formed. The results demonstrated the complementary nature of the techniques used for studying lateral diffusion couples.

Study of Iridium/Germanium Interaction in a Lateral Diffusion Couple. A.Habanyama, C.M.Comrie: Thin Solid Films, 2008, 516[15], 5137-43