Nanometric patterning with ultrathin twist bonded silicon wafers

Ultrathin films of silicon bonded on 4-inch (001) silicon wafers have been obtained by combining a direct hydrophobic silicon bonding technique with a layer transfer. The strain field produced by the dislocation network local ized at the bonded interface is a good candidate to induce a long-range ord er growth of nanostructure. To be able to make this new kind of substrate, knowledge of the dislocation strain field extension is essential. Grazing i ncidence X-ray diffraction allows us to measure its spatial extension throu gh the diffraction peak satellites due to different dislocation networks. T he exponential decay of these peaks were measured and compared. We found th at the decrease of the strain field extension is almost two times lower for the screw dislocation network than for the 'mixed' dislocations one. The f ilm thickness control is then two times more critical for the screw disloca tions. (C) 2000 Elsevier Science B.V. All rights reserved.