comprises an oxide layer and an amorphous layer on each of its faces referenced 11 u2032 and 12 u2032 on the lower face but it should be understood that it would suffice for such layers 11 and 12 to exist on only one of the faces of the substrate 10 using electrochemistry a second substrate 20 is here over only part of its thickness under a free surface rendered porous for example by treatment with an hf based solution under appropriate conditions this porous layer 21 has for example a thickness of 10 microns this substrate 20 is advantageously a wafer similar to the wafer from which the first substrate 10 was formed the configuration of fig2 is thus obtained this second substrate 20 is monocrystalline here with an orientation lt 001 gt it is for example a 1 ohm cm doped n type silicon to which a current density of 400 ma cm 2 has been applied without illumination at the back face after an optional treatment consisting here of a treatment by hf in solution or in vapor phase the two free surfaces of the first and second substrate 10 and 20 i e the free surfaces of the layers 12 and 21 are bonded by hydrophobic molecular bonding the molecular bonding is sometimes termed u201c molecular adhesion u201d the configuration of fig3 is thus obtained thermal annealing is next carried out in order to induce the recrystallization in solid phase of the amorphous layer 12 into monocrystalline silicon according to the crystal parameters 21 which thus constitute through the molecular bonding interface a recrystallization seed forming reference layer this annealing may for example consist of a temperature ramp of 0 5 u00b0 c min between.