One or more embodiments of the disclosure concerns a method of forming a stressed semiconductor layer involving: forming, in a surface of a semiconductor structure having a semiconductor layer in contact with an insulator layer, at least two first trenches in a first direction; introducing, via the at least two first trenches, a stress in the semiconductor layer and temporally decreasing, by annealing, the viscosity of the insulator layer; and extending the depth of the at least two first trenches to form first isolation trenches in the first direction delimiting a first dimension of at least one transistor to be formed in the semiconductor structure.