MEMS ultrasonic transducer device with improved damping of the oscillations of a membrane of the same, and manufacturing process of the same

A device, comprising:

• a semiconductor body of semiconductor material having a first main face and a second main face opposite to the first main face;
• a first chamber within the semiconductor body;
• a second chamber within the semiconductor body, the second chamber is between the first chamber and the second main face;
• a central fluidic passage that extends into the second main face, extends through the second chamber, and extends to the first chamber;
• a plurality of lateral fluidic passages extends into the second main face to the second chamber, and each respective lateral fluidic passage of the plurality of lateral fluidic passages is spaced laterally outward from the central fluidic passage;
• a membrane that extends from the first chamber to the first main face;
• and
• a piezoelectric element on the first main face of the semiconductor body, and the piezoelectric element fully overlaps the central fluid passage.

A device, comprising:

• a semiconductor body of semiconductor material having a first main face and a second main face opposite to the first main face;
• a first chamber within the semiconductor body, the first chamber having a first diameter;
• a second chamber within the semiconductor body, the second chamber is between the first chamber and the second main face, the second chamber having a second diameter less than the first diameter;
• a central fluidic passage that extends into the second main face, extends through the second chamber, and extends to the first chamber, the central fluidic passage includes a third diameter less than the first diameter and less than the second diameter;
• a plurality of lateral fluidic passages extends into the second main face to the second chamber, and each respective lateral fluidic passage of the plurality of lateral fluidic passages is spaced laterally outward from the central fluidic passage;
• a membrane that extends from the first chamber to the first main face, the membrane being concentric with the first chamber and the second chamber;
• and
• a piezoelectric element on the first main face of the semiconductor body, and the piezoelectric element fully overlaps the central fluid passage.