Microelectromechanical device with movable mass and stopping structure having improved mechanical robustness

A device, comprising:

• a supporting body including a semiconductor material and a surface;
• a movable mass constrained to the supporting body with a relative degree of freedom with respect to a first motion direction perpendicular to the surface of the supporting body, the movable mass includes a first through opening that passes entirely through the movable mass, the movable mass is suspended over the surface of the supporting body, the movable mass including a first protrusion portion extending into the first through opening;
• a stopping structure configured to, in operation, limit out-of-plane movements of the movable mass along the first motion direction, the stopping structure including:
• a first anchor block extending through the first through opening and is anchored to the supporting body;
• a connection element coupled to the first anchor block, the connection element including a surface facing towards the surface of the supporting body;
• a first cavity that extends into the first anchor block in a direction transverse to the first motion direction and parallel to the surface of the support body, and the first cavity is delimited by the first anchor block and the surface of the connection element, wherein the first protrusion portion of the movable mass is in the first cavity;
• and
• a first bump extending outward from the surface of the connection element, the first bump overlapping the first protrusion portion of the movable mass in the first cavity.

A method, comprising:

• forming one or more portions of a first sacrificial layer on a surface of a supporting body;
• forming a first structural layer on the one or more portions of the first sacrificial layer and on the surface of the supporting body;
• forming a plurality of trenches extending into and through the first structural layer to the one or more portions of the first sacrificial layer;
• forming a second sacrificial layer on a surface of the first structural layer, and partially filling the plurality of trenches with the second sacrificial layer;
• removing one or more portions of the second sacrificial layer forming at least one depression overlapping the first sacrificial layer;
• forming a second structural layer on remaining portions of the second sacrificial layer and on the first structural layer, and filling the depression of the second sacrificial layer with the second structural layer defining a bump of the second structural layer;
• removing one or more portions of the second structural layer;
• and
• removing the remaining portions of the second sacrificial layer and removing the one or more portions of the first sacrificial layer exposing the bump of the second structural layer.