Method for sealing cavities using membranes

A method for sealing a plurality of cavities using a plurality of membranes, the method comprising:

• (a) forming a plurality of cavities opening at a front face of a support substrate or at a sealing face of a sealing film, wherein the cavities are arranged in a matrix, have a depth p, have a characteristic dimension a, and are spaced apart by a spacing distance b;
• and
• (b) forming a plurality of membranes, sealing each of the cavities, by transferring the sealing film overlapping with the front face, the transferring comprising assembling the sealing face with the front face,
• wherein the method further comprises a step (a1), executed before step (b), of forming a first contour on at least one of the front face and the sealing face, the first contour comprising a continuous first trench having a width L and a first depth p1, the formation of the first contour being executed such that, after step (b), the plurality of cavities is circumscribed by the first contour, said first contour being at an essentially constant distance G from the plurality of cavities, with G being between b/5 and 5b.