A process for transferring a buried circuit layer comprises taking a donor substrate comprising an internal etch stop zone and covered on its front side with a circuit layer, producing over the entire circumference of the donor substrate either a peripheral trench or a peripheral routing, the routing or trench being produced over a depth such that they pass entirely through the circuit layer and extend into the donor substrate, depositing on the circuit layer and on the routed side or on the walls of the trench a layer of an etch stop material that is selective with respect to etching of the circuit layer, without filling the trench, bonding a receiver substrate to the donor substrate, and thinning the donor substrate by etching its back side until reaching the etch stop zone so as to obtain the transfer of the buried circuit layer to the receiver substrate.