A nanometer patterning method, based on local oxidation of silicide layers, was used to pattern epitaxial CoSi2 layers. A feature size as small as 50 nm was obtained for 20 nm epitaxial CoSi2 layers on Si(100) after patterning by local rapid thermal oxidation in dry oxygen. A Schottky source/drain metal–oxide–semiconductor field effect transistor with epitaxial CoSi2 on p-Si(100) was fabricated using this nanopatterning method to make the 100 nm gate. The device shows good I–V characteristics at 300 K.

Epitaxial CoSi 2 ͑001͒ layers, deposited on Si͑001͒ substrates by molecular beam allotaxy, were used as substrates for diamond deposition in order to realize applications. The nucleation and textured growth of diamond films were compared with those on the Si͑001͒ substrates. The results indicate that in a microwave-plasma chamber diamond can be nucleated with a higher density on CoSi 2 at lower temperatures using a bias-enhanced method. High-quality ͓001͔-textured diamond films can be synthesized on CoSi 2 ͑001͒ using the ͓001͔-textured growth conditions. So far, epitaxial growth of diamond on CoSi 2 cannot be observed. Statistically, a rotating angle distribution of diamond grains around the ͓001͔ axis in a ͓001͔-textured film shows, however, preferred in-plane orientations of 13°, 22°, 45°, and 77°relative to the CoSi 2 ͓011͔ axis. The structural and chemical analyses show that no Co and Si element diffusion from the CoSi 2 substrate into the diamond film can be detected. The films grown on CoSi 2 have similar crystal quality to that of epitaxial films deposited directly on Si.

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A series of buried CoSi 2 layers prepared by a modified molecular beam epitaxy process ͑allotaxy͒ and a subsequent wet-oxidation process was investigated by x-ray scattering. The oxidation time which determines the depth in which the CoSi 2 layers are located within the Si substrates has been varied during the preparation. The electron density profiles and the structure of the interfaces were extracted from specular reflectivity and diffuse scattering measurements. Crystal truncation rod investigations yielded the structure on an atomic level ͑crystalline quality͒. It turns out that the roughness of the CoSi 2 layers increases drastically with increasing oxidation time, i.e., with increasing depth of the buried layers. Furthermore, the x-ray data reveal that the oxidation growth process is diffusion limited.

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