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 localized at the bonded interface is a good candidate to induce a long-range order growth of nanostructure. To be able to make this new kind of substrate, knowledge of the dislocation strain field extension is essential. Grazing incidence X-ray diffraction allows us to measure its spatial extension through the diffraction peak satellites due to different dislocation networks. The exponential decay of these peaks were measured and compared. We found that the decrease of the strain field extension is almost two times lower for the screw dislocation network than for the 'mixed' dislocations one. The film thickness control is then two times more critical for the screw dislocations.