Thin-film piezoelectric microelectromechanical structure having improved electrical characteristics and corresponding manufacturing process

A process for manufacturing a piezoelectric microelectromechanical structure, comprising:

• forming a piezoelectric stack having a main extension in a horizontal plane and variable cross-sectional thickness in a plane transverse to said horizontal plane, by forming, stacked on one another, a bottom-electrode region, a piezoelectric material region arranged on the bottom-electrode region, and a top-electrode region arranged on the piezoelectric material region;
• and
• forming the piezoelectric material region to have, as a result of said variable cross-sectional thickness, a first thickness along a vertical axis transverse to said horizontal plane at a first area, and a second thickness along said vertical axis at a second area thereof;
• wherein the second thickness is smaller than the first thickness.

A piezoelectric microelectromechanical structure comprising a piezoelectric actuator and a piezoelectric detector, said piezoelectric microelectromechanical structure comprising:

• a membrane extending parallel to a horizontal plane;
• a piezoelectric stack supported by the membrane and formed by a stacked arrangement of a bottom-electrode region, a piezoelectric material region arranged on the bottom-electrode region, and a top-electrode region arranged on the piezoelectric material region;
• wherein said piezoelectric stack comprises a first stack portion and a second stack portion, said first and second stack portions being separate and distinct;
• wherein the piezoelectric material region of the piezoelectric stack has a variable cross-sectional thickness including:
• a first thickness along a vertical axis transverse to said horizontal plane at the first stack portion to provide said piezoelectric detector;
• and a second thickness along the vertical axis at the second stack portion, the second thickness being smaller than the first thickness, to provide said piezoelectric actuator.