Process for manufacturing mems devices having buried cavities and mems device obtained thereby

A MEMS device comprising:

• a bottom region;
• a membrane region of semiconductor material;
• and
• a buried cavity arranged between the bottom region and the membrane region, wherein:
• the membrane region includes a polycrystalline structure including a plurality of apertures extending through a thickness of the membrane region and conformally coated with a porous material layer along a side wall and a bottom of each aperture;
• the apertures being filled with filling material.

A pressure sensor comprising;

• an interface circuit configured to detect capacitance changes and to output an electrical quantity;
• and
• a MEMS device coupled to the interface circuit and including:
• a bottom region;
• a membrane region, of semiconductor material;
• and
• a buried cavity arranged between the bottom region and the membrane region, wherein:
• the membrane region includes a polycrystalline structure including a plurality of apertures extending through a thickness of the membrane region and conformally coated with a porous material layer along a side wall and a bottom of each aperture;
• the apertures being filled with filling material.