Difficulty for oxygen to incorporate into the silicon network during initial O2 oxidation of Si(100)-(2×1)
Résumé
First principles calculations and scanning tunneling microscopy studies of the oxidation of Si(100)-(2×1) surfaces by molecular oxygen reveal that the surface silanone (O)(Si=O) species is remarkably stable, constituting the key intermediate for initial oxidation. The propensity for oxygen to remain within the top surface layer as opposed to incorporating within Si–Si backbonds is surprisingly high. This resistance to incorporation into a cubic lattice even at higher coverages could be a factor to facilitate surface amorphization in subsequent steps.