Process for encapsulation of a microelectronic device by easily manipulated thin or ultrathin substrates

A process for encapsulation of a microelectronic device placed on a support substrate, with an encapsulation cover comprising the following successive steps:

• a) supplying the support substrate made of a first material, comprising a first principal face on which the microelectronic device is placed, a second principal face opposite the first principal face, and a lateral face,
• b) depositing a bonding layer made of a second material on the first principal face of the substrate, around the microelectronic device,
• c) positioning the encapsulation cover made of a third material, comprising a first principal face, a second principal face opposite the first principal face, and a lateral face on the bonding layer, so as to fix the encapsulation cover on the support substrate so as to encapsulate the microelectronic device,
• d) depositing a lateral protection layer made of a fourth material on the lateral face of the support substrate, on the lateral face of the encapsulation cover, on a periphery of the second principal face of the encapsulation cover, and around a periphery of the second principal face of the support substrate, the lateral protection layer delimiting a protected zone and,
• e) thinning of the second principal face of the support substrate and/or the second principal face of the encapsulation cover outside the protected zone, by chemical etching.