Ion beam analysis using micro-Rutherford back-scattering spectrometry was used to investigate the interaction between germanium and iridium in a lateral diffusion couple. Optical microscopy, scanning electron microscopy and atomic force microscopy had also been employed. When samples of germanium islands on iridium films were annealed at 600 to 800C, substantial lateral diffusion was observed, resulting in a number of reaction regions. Micro-Rutherford backscattering analysis indicated that the phase Ir3Ge7 stretches across the original island interface at all temperatures, with the phase Ir4Ge5 forming in the reaction region with unreacted iridium. The phase IrGe4 was observed to nucleate in the middle of the island at temperatures above 800C. Depth information was readily obtainable from micro-Rutherford backscattering 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