Carbonization-driven motion of Si islands on epitaxial graphene

We investigate structural changes in Si islands deposited at room temperature on epitaxial few-layer graphene on SiC(0001) during subsequent annealing. Annealing causes the Si islands move on epitaxial graphene thicker than monolayer with monolayer-deep trenches left behind. In contrast, Si islands do not form trenches on monolayer graphene, but the Si atoms are intercalated to form quasifreestanding bilayer graphene. The islands which terminated their motion are made of SiC. During annealing, Si islands are carbonized into SiC islands by incorporating carbon atoms from graphene, resulting in the etching of graphene. The carbonization reaction of Si is a driving force of the motion of the Si islands.

Automated summary

We investigate the structural changes in Si islands deposited on epitaxial few-layer graphene on SiC(0001) at room temperature during subsequent annealing. Annealing causes the movement of Si islands on thick epitaxial graphene and leaves behind monolayer-deep trenches. In contrast, Si islands do not form trenches on monolayer graphene, but instead intercalate to form quasifreestanding bilayer graphene. The termination of island motion results in SiC islands. Si islands are carbonized into SiC islands during annealing by incorporating carbon atoms from graphene, leading to the etching of graphene. The carbonization reaction of Si is the driving force behind the motion of Si islands.