Method for preparing a carrier substrate provided with a charge-trapping layer

A method of forming a support substrate (equipped with a charge-trapping layer, the method comprising introducing a single-crystal silicon base substrate having a resistivity of less than or equal to 500 ohm.cm into a chamber of deposition equipment and, without removing the base substrate from the chamber and while flushing the chamber with a carrier gas, performing the following successive steps:

• forming an intrinsic silicon epitaxial layer on the base substrate by introducing into the chamber a precursor gas containing silicon, for a given time period;
• forming a dielectric layer on the intrinsic silicon epitaxial layer by introducing a reactive gas into the chamber over a first time period;
• and
• forming the polycrystalline silicon charge-trapping layer directly on the dielectric layer by introducing a precursor gas containing silicon into the chamber over a second time period, subsequent to the first time period;
• wherein a time for which the dielectric layer is exposed only to the carrier gas, between the first time period and the second time period, is less than 30 seconds and the step of forming the charge-trapping layer is performed at a temperature strictly between 1010°C. and 1200°C.