Treatment of a thin film by hydrogen plasma and polarisation in order to improve the crystalline quality thereof

A method for treating a thin film made from a conductive or semiconductive material to improve the crystalline quality thereof, the method comprising:

• supplying a substrate comprising, on one of the faces thereof, a thin film of the material;
• and
• biased plasma treating the assembly formed by the substrate and the thin film at a given temperature and for a given time, so as to obtain a crystalline reorganization over a depth of the thin film,
• wherein the biased plasma treating comprises an electrical biasing of the thin film and exposing the film thus biased to a hydrogen plasma,
• wherein the biased plasma treating is implemented at a temperature that is below the melting points of the thin film and of the substrate,
• wherein the hydrogen plasma is obtained from a gas consisting of hydrogen and helium,
• wherein the gas is devoid of any precursor of the conductive or semiconductive material of the film,
• wherein a time of the exposure of the biased film to the hydrogen plasma is in a range of from 10 minutes to several hours,
• wherein, in the supplying, the face of the substrate is monocrystalline and the thin film present on the face is polycrystalline, and
• wherein the biased plasma treating is implemented until the polycrystalline film becomes an epitaxial film.