Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms vol:59 pages:660-665
The formation of monocrystalline (100) CoSi2 layers is obtained by a thin-film reaction of sputtered Co with the top Si layer of Si/CoSi2/Si heterostructures, formed by ion implantation. The buried CoSi2 layer serves as an excellent seed for imposing its crystal structure on the newly grown top CoSi2. A noncontinuous buried layer can also serve as a seed, hereby reducing the required implanted dose. The combination of ion implantation and regular silicide formation, therefore, becomes an attractive technique to form surface layers of monocrystalline (100) CoSi2 on (100) Si. Patterned layers can be obtained by a masked ion implantation and a self-aligned Co-silicidation. In order to understand the relation between the amount of Co to be implanted versus the thickness and quality of the overgrown layer, a detailed study has been performed, for a wide range of implanted doses. Parameters of interest are the implantation energy to define the initial CoSi2 precipitate distribution, the thickness of the sputtered Co layer and the anneal cycle for silicidation.