Method for manufacturing an electronic device

A manufacturing method of a resonant electronic device, the manufacturing method comprising the following successive steps:

• a provision step, wherein a primary stack and a receiver stack are provided, the receiver stack having a receiving face;
• the primary stack being obtained by the following steps:
• a supply step, wherein an initial stack is supplied, the initial stack comprising:
• an initial substrate having a front face, the front face comprising a central zone and a peripheral trimming zone, the peripheral trimming zone being adjacent to a peripheral edge of the front face on the one hand, and surrounding the central zone on the other hand;
• a thin resonant layer made of piezoelectric material having an upper surface facing the initial substrate and a lower surface opposite the upper surface;
• a bonding layer, interposed between the central zone of the initial substrate, and the upper surface of the resonant thin layer;
• and
• lower electrodes in electrical contact with the lower surface of the resonant thin layer
• a protecting step, in wherein a protective thin layer is deposited on the initial stack on the side of the lower surface of the resonant thin layer, the protective thin layer covering the peripheral trimming zone;
• the protective thin layer being made of a material having an acoustic impedance greater than 20 MRayl for longitudinal waves and/or greater than 12 MRayl for shear waves, the primary stack being formed at the end of the protecting step;
• a bonding layer deposition step, wherein a bonding layer is deposited on the lower surface side of the resonant thin layer;
• a bonding step, wherein the receiving face of the receiver stack, and the bonding layer are brought into intimate contact, so as to secure the primary stack to the receiver stack;
• a removal phase, wherein the initial substrate and the bonding layer are removed mechanically and chemically;
• and
• an electrode definition step, wherein upper electrodes are deposited on the upper surface of the resonant thin layer, then defined by photolithography, etching and resin removal, so that the upper electrodes are in electrical contact with the resonant thin layer.