Structural characterization of oxidized allotaxially grown CoSi2 layers byx-ray scattering

A series of buried CoSi2 layers prepared by a modified molecular beam epita xy process (allotaxy) and a subsequent wet-oxidation process was investigat ed by x-ray scattering. The oxidation time which determines the depth in wh ich the CoSi2 layers are located within the Si substrates has been varied d uring the preparation. The electron density profiles and the structure of t he interfaces were extracted from specular reflectivity and diffuse scatter ing measurements. Crystal truncation rod investigations yielded the structu re on an atomic level (crystalline quality). It turns out that the roughnes s of the CoSi2 layers increases drastically with increasing oxidation time, i.e., with increasing depth of the buried layers. Furthermore, the x-ray d ata reveal that the oxidation growth process is diffusion limited. (C) 2000 American Institute of Physics. [S0021-8979(00)00901-4].