Method for selectively filling, with a filling liquid, a group of cavities from among a plurality of cavities

A method for selectively filling, with a filling liquid, a first cavity of at least one group of cavities each opening out onto a front face of a substrate, each of the cavities comprising an inner surface, the method comprising the following steps:

• a) a treatment step for modifying a surface energy of the inner surface of the first cavity, referred to as a first surface, and surface energies of the inner surfaces, referred to as second surfaces, of second cavities other than the first cavity, such that the first surface has a first surface energy and the second surfaces have a second surface energy different from the first energy;
• and
• b) a step which comprises at least one sequence of spreading the filling liquid on the front face,
• the first surface energies and the second surface energies being adjusted such that the first and the second surfaces exert an attracting and repelling effect respectively on the filling liquid, step b) thus resulting in the selective filling, by the filling liquid, of the first cavity with respect to the second cavities,
• wherein step a) comprises a plasma treatment or a treatment with ultraviolet radiation performed selectively on the first surface or on the second surfaces, and
• wherein step b) comprises:
• spreading a first liquid to fill the first cavity, and
• spreading a second liquid over the first and second cavities, filling at least one of the second cavities and forming a layer of the second liquid remaining to cover the filled first cavity.