Abstract:
A process for manufacturing a micromechanical structure (25) envisages: forming a buried cavity (10) within a body (1, 12) of semiconductor material, separated from a top surface (12a) of the body by a first surface layer (12); and forming an access duct (18a) for fluid communication between the buried cavity (10) and an external environment. The method envisages: forming an etching mask (14) on the top surface (12a) at a first access area (17a); forming a second surface layer (15) on the top surface (12a) and on the etching mask (14); carrying out an etch such as to remove, in a position corresponding to the first access area, a portion of the second surface layer (15), and an underlying portion of the first surface layer (12) not covered by the etching mask (14) until the buried cavity is reached, thus forming both the first access duct (18a) and a filter element (20), set between the first access duct and the same buried cavity.