Abstract: A method for manufacturing an optoelectronic device includes providing a support supporting a plurality of three-dimensional semiconductor structures, forming a sacrificial portion under a first set of 3D structures of the plurality of three-dimensional semiconductor structures, forming a barrier portion around the sacrificial portion, said barrier portion having a basal wall extending under the sacrificial portion, and a lateral wall extending at the edge of the sacrificial portion, forming an access trench up to the sacrificial portion, the access trench extending continuously along the lateral wall of the barrier portion, etching the sacrificial portion from the access trench, and removing the first set of 3D structures.