The invention relates to a method for manufacturing a semiconductor on insulator type substrate for radio frequency applications, comprising the following steps in sequence: (a) provision of a silicon substrate with an electrical resistivity of more than 500 Ohm.cm, (b) formation of a polycrystalline silicon layer on the substrate, the method comprising a step between steps a) and b) to form a dielectric material layer, different from a native oxide layer, on the substrate, between 0.5 and 10 nm thick.