Method for preparing a thin layer that includes forming a weakened zone in a central portion of a donor substrate that does not extend into a peripheral portion of the donor substrate and initiating and propagating a splitting wave in the weakened zone that does completely not propagate through the peripheral portion

A method for preparing a thin layer, comprising the following steps:

• a weakening step comprising the introduction of light species through a main face of a donor substrate, the weakening step forming a weakened zone in a central portion of the donor substrate to define the thin layer with the main face of the donor substrate, the weakened zone not extending into a peripheral portion of the donor substrate;
• a joining step comprising joining the main face of the donor substrate to a receiver substrate to form an assembly to be split, the central portion and the peripheral portion of the main face of the donor substrate being brought into contact with a face of the receiver substrate;
• a separating step comprising separating the assembly to be split by application of a heat treatment resulting in the initiation and propagation of a splitting wave in the weakened zone to free the thin layer from the donor substrate at the central portion thereof only, the splitting wave not propagating completely through the peripheral portion such that the donor substrate and the receiver substrate remain attached to one another at the peripheral portion of the donor substrate;
• and
• a detaching step distinct from the separating step and applied after the separating step, the detaching step comprising treating of the assembly to be split to detach the peripheral portion of the donor substrate from the receiver substrate and thus transfer the thin layer to the receiver substrate.