Method for modifying a stress level of a semiconductor device having transistor channel stages

A method of making a microelectronic device provided with at least one first transistor with a first channel structure formed from semiconducting elements located above each other, the method comprising steps to:

• a) provide at least one first semiconducting structure on a substrate, formed from a semiconducting stack comprising an alternation of elements based on at least one first semiconducting material and elements based on at least one second semiconducting material different from the first semiconducting material, then
• b) remove portions of the second semiconducting material from the first structure by selective etching, the removed portions of the second semiconducting material forming one or several empty spaces,
• c) fill in the empty spaces with a dielectric material,
• d) form a straining zone on the first structure, based on a first strained material with an intrinsic strain,
• e) perform appropriate thermal annealing so as to make the dielectric material creep, and cause a change in the strain state of elements based on the first semiconducting material in the first structure.