Method for manufacturing a structure comprising a plurality of membranes overhanging cavities

A method for manufacturing a structure comprising a plurality of membranes each overhanging a cavity, the manufacturing method comprising the following steps:

• a) a step of forming cavities opening at a front face of a support substrate, the cavities having a depth (p) and an area (A) in a plane of the front face, and being spaced apart by a spacing (e);
• b) a step of assembling, by way of direct bonding, a donor substrate on the support substrate, at their respective front faces, so as to seal the cavities under vacuum, the direct bonding being hydrophilic and involving a given number (N) of water monolayers at a contact interface between the donor substrate and the support substrate;
• and
• c) a step of transferring a thin layer from the donor substrate onto the support substrate, the thin layer comprising the membranes in line with the cavities;
• wherein:
• a specific area(S) is defined around each of the cavities, in a plane of the contact interface, the specific area(S) being expressed as a function of half of the spacing;
• and
• the area (A), the depth (p) of each of the cavities, and the specific area(S) are defined in step a) to satisfy the following relationship:
• S/A=(Patm×p)/(N×1015×kB×T), where Patm is atmospheric pressure, N is the number of water monolayers at the contact interface, kb is the Boltzmann constant and T is the ambient temperature.