Epitaxy of CoSi2Si(100): from Co/Ti/Si(100) to reactive deposition epitaxy

High-quality CoSi2(100) layers in the thickness range of 200 to 500 Å are formed by reactive deposition epitaxy. A model is described in which the deposition rate and substrate temperature are crucial in determining the epitaxial nature of the silicide. It is shown that good CoSi2Si(100) alignment is only achieved when using low deposition rates (in the order of 0.1 Å/s or less) combined with relatively high substrate temperatures during deposition (∼600°C). At higher rates and/or lower temperatures, a fraction of misoriented CoSi2 grains is formed. A study of the crystalline quality of the CoSi2 layers as a function of Co flux and deposition temperature is presented, and special attention is devoted to the thermal stability of the layers during high temperature annealing.