producing, on a substrate, at least one thermal detector, which is covered by at least one mineral sacrificial layer made of a mineral material able to be removed by a first chemical etch;

producing a through-aperture that extends through the mineral sacrificial layer and that opens onto the substrate;

producing a getter segment made of a metal that has a gettering effect, the getter segment being placed on and in contact with the substrate and at a distance from the thermal detector in a plane parallel to the substrate, the getter segment being located in the through-aperture, at a distance from a lateral border that is defined by the mineral sacrificial layer and that bounds the through-aperture in the plane parallel to the substrate;

producing a carbon-containing sacrificial layer made of a carbon-containing material that is inert to the first chemical etch and that is able to be removed by a second chemical etch, so as to cover the getter segment and to surround it in the plane parallel to the substrate, and to completely fill the through-aperture;

producing a thin encapsulation layer comprising: a top portion that rests on the mineral sacrificial layer and on the carbon-containing sacrificial layer; and a peripheral portion that extends through the mineral sacrificial layer and that surrounds the thermal detector and the getter segment;

removing the mineral sacrificial layer via the first chemical etch; and

removing the carbon-containing sacrificial layer via the second chemical etch.