Patent ID: 8470690

Claim:
A method of fabricating a multilayer film ( 2 ′) comprising at least one ultrathin layer ( 2 ) of crystalline silicon, the film being fabricated from a substrate (S) having a crystalline structure and including a previously-cleaned surface, the method being characterized in that it comprises the following steps: a) exposing said cleaned surface to a radiofrequency plasma generated in a gaseous mixture of SiF 4 , hydrogen, and argon, the power density of the radiofrequency plasma lying in the range 100 mW/cm 2 to 600 mW/cm 2 , the pressure of the gaseous mixture in the range 200 Pa to 400 Pa, the temperature of the substrate (S) lying in the range 150° C. to 300° C., the flow rate of SiF 4 lying in the range 1 cm 3 /min to 10 cm 3 /min, the flow rate of hydrogen lying in the range 1 cm 3 /min to 60 cm 3 /min, the flow rate of argon lying in the range 1 cm 3 /min to 80 cm 3 /min, so as to form on said cleaned surface an ultrathin layer of crystalline silicon ( 2 ) comprising a plurality of sublayers ( 19 , 20 , 21 ) including an interface sublayer ( 19 ) in contact with the substrate (S) and containing microcavities; b) depositing at least one layer of material on said ultrathin layer of crystalline silicon ( 2 ) so as to co-operate with said ultrathin layer of crystalline silicon ( 2 ) to form a multilayer film ( 2 ′), said multilayer film including at least one mechanically strong layer ( 3 ) so as to form a multilayer film ( 2 ′) having sufficient strength to enable said multilayer film ( 2 ′) to be separated without damaging the ultrathin layer of crystalline silicon ( 2 ); and c) annealing the substrate (S) covered in said multilayer film ( 2 ′) at a temperature higher than 400° C., thereby enabling said multilayer film ( 2 ′) to be separated from the substrate (S).