Method for making a device for detecting electromagnetic radiation comprising a layer of getter material

A method for making an electromagnetic radiation detecting device comprising at least one thermal detector, the latter comprising an absorbent membrane suitable for absorbing the radiation to be detected, suspended above a substrate, the thermal detector being intended to be located in a sealed cavity, said method comprising at least the following steps:

• depositing, on the substrate, a gettering metallic layer comprising a metallic material with a gettering effect;
• depositing, so as to cover the gettering metallic layer, a carbonaceous sacrificial layer comprising a carbonaceous material of amorphous carbon that can be etched selectively with respect to the gettering metallic layer by a second chemical etching;
• depositing, on the carbonaceous sacrificial layer, at least one sacrificial mineral layer comprising a mineral material that can be etched selectively with respect to the carbonaceous sacrificial layer by a first chemical etching;
• chemical-mechanical planarization of the sacrificial mineral layer;
• fabricating the thermal detector so that the absorbent membrane is produced on the sacrificial mineral layer;
• removing the sacrificial mineral layer by said first chemical etching;
• and
• removing the carbonaceous sacrificial layer by said second chemical etching.