[en] A high-resistivity defect layer buried beneath the silicon surface layer by using proton implantation and two-step conventional furnace annealing is described. During the first annealing step (600degC), implanted hydrogen atoms move towards the damage region and then coalesce into hydrogen gas bubbles at the residual defect layer. During the second annealing step (1180degC) these bubbles do not move due to their large volume. Structural defects are formed around the bubbles at a depth of ≅0.5 μm. The defect layer results in a high resistivity value. Experiments show that the quality of the surface layer has been improved because the surface Hall mobility increased by 20%. The sample was investigated by transmission electron microscopy. (orig.)