Guide slot forming method for e.g. intra-optical connections of silicon chip, involves filling trenches with silicon, and carrying out annealing of silicon oxide layer after performing formation, graving or filling steps

The method involves forming non stoichiometric silicon oxide layer on an etch stop layer (22) that is made of silicon dioxide or silicon, and is superficial layer of silicon on insulator. Two trenches parallel to each other are graved on the etch stop layer with the help of a hard mask that is made of a metal or resin, where the trenches are separated by a silicon oxide wall (36). The trenches are filled with amorphous, polycrystalline or monocrystalline silicon (42, 44). An annealing of the silicon oxide layer is carried out after performing formation, graving or filling steps. L'invention concerne un procédé de réalisation d'un guide à fente, dans lequel :- a) on forme une couche de SiOx (26) non stoechiométrique (x