Process for manufacturing a membrane of semiconductor material integrated in, and electrically insulated from, a substrate

A microelectromechanical structure, comprising:

• a monolithic body of semiconductor material having a front face;
• and a buried cavity, extending at a distance from said front face and delimiting with said front face a membrane, which is suspended above said buried cavity;
• and
• an insulation structure in a surface portion of said monolithic body, surrounding said membrane at a non-zero distance of separation and configured to electrically insulate said membrane from said monolithic body.

A process, comprising:

• forming at least two voids in a substrate and a membrane formed from the substrate material to completely cover at least one of the at least two voids;
• forming a trench completely around the membrane at a non-zero distance from the membrane and extending into the substrate to a depth that is at least a depth of at least one of the at least two voids in the substrate and in communication with at least one of the at least two voids;
• and
• forming a buried insulation region completely around the trench and all of the at least two voids via the trench to electrically insulate the membrane from a remainder of the substrate.