First-principles study on Si(−220)/6H–SiC(0001) interface

A periodical structure with low lattice mismatch at Si(−220)/6H–SiC(0001) interface has been confirmed by HRTEM. Corresponding to the observed interface structure, the first-principles calculations based on the density functional theory are employed to understand the bonding mechanism of the surface states. It is shown that the combination of Si with C-terminated 6H–SiC surface is more stable than that with Si-terminated surface, but a strong fold caused by considerable interaction of C-2p and Si-3p states at the interface with C-termination may introduce a high density of structural defects in the subsequently epitaxial Si film. Meanwhile, relaxation energy of the interface with C-terminated 6H–SiC surface is bigger than that with Si-terminated surface. It means that it is easier to deposit Si films in (−220) orientation on Si-faced 6H–SiC(0001) substrates at a relative low temperature.

Highlights

• A periodical structure with low lattice mismatch on the Si(−220)/6H–SiC(0001) interface has been confirmed by HRTEM.

• First-principles calculations based on the density functional theory are employed to understand the interface structure.

• The interaction of C-2p and Si-3p states at the interface may introduce structural defects in subsequently epitaxial Si film.

• It is theoretically easier to deposit Si(−220) films on Si-faced 6H–SiC(0001) substrates at a relatively low temperature.

Source: Solid State Communications

If you need more information about First-principles study on Si(−220)/6H–SiC(0001) interface, please visit our website:http://www.qualitymaterial.net, send us email at powerwaymaterial@gmail.com.