Electromagnetic radiation detector encapsulated by transfer of thin layer

Method of encapsulating at least one sensitive element of an electromagnetic radiation detector (100), characterised in that it comprises the following steps:

• a) fabrication of a stack, called the sensor stack (117), comprising:
• a first substrate (101), called the principal substrate;
• at least one membrane (108) extending above the principal substrate, forming the at least one sensitive element of the electromagnetic radiation detector, and configured to absorb an incident electromagnetic radiation and convert it into heat;
• support walls (106) extending above the principal substrate and surrounding the at least one membrane;
• and
• a first metallic sealing layer (112A) located above upper faces of the support walls, on the side opposite the principal substrate;
• b) deposition of a layer called the cap layer (132), transparent in a spectral sensitivity range of the electromagnetic radiation detector and less than or equal to 10 μm thick, above a second substrate (130) called the transfer substrate;
• c) production of a second metallic sealing layer (112B) on the cap layer;
• d) transfer of the transfer substrate (130) onto the principal substrate (101), so as to align the first sealing layer (112A) and the second sealing layer (112B) and bond them to each other;
• and
• e) removing of the transfer substrate (130).