One or more embodiments of the invention concerns a method of forming a semiconductor layer having uniaxial stress including: forming, in a surface of a semiconductor structure having a stressed semiconductor layer and an insulator layer, at least two first trenches in a first direction delimiting a first dimension of at least one first transistor to be formed in the semiconductor structure; performing a first anneal to decrease the viscosity of the insulating layer; and forming, in the surface after the first anneal, at least two second trenches in a second direction delimiting a second dimension of the at least one transistor.