Control of interfacial morphology: NiSi2/Si(100)

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Abstract
The structure and morphology of thin and ultrathin epitaxial NiSi2 layers on Si(100) grown by various techniques have been studied in detail. Very high‐quality single‐crystal NiSi2 layers have been grown on Si(100). Codeposition of stoichiometric NiSi2 at low temperatures followed by subsequent annealing at high temperatures (≥700 °C) has been shown to eliminate the most common problem for this epitaxial system, namely, faceting at the interface. Line defects, associated with interface roughness, were also greatly reduced in films grown by this method. Interfacial faceting and defects at interface domain boundaries appear to be related to the growth kinetics and are not due to energetic advantages, as previously thought. Discrete spots around the (01/2 1/2)‐related reflections were observed by transmission electron diffraction from some planar NiSi2 layers, suggesting the existence of superstructures at portions of the NiSi2/Si interface. Low‐energy electron diffraction indicated the existence of a highly ordered surface reconstruction for well‐annealed films. Possible growth models, as well as the implications of possible structural inhomogeneity on interface electron transport measurements, are discussed.