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.
Abstract:
A process for manufacturing components in a multi-layer wafer, including the steps of: providing a multi-layer wafer (8) comprising a first semiconductor material layer (9), a second semiconductor material layer (21), and a dielectric material layer (10) arranged between the first and the second semiconductor material layer (8, 9); and removing the first semiconductor material layer (9) initially by mechanically thinning the first semiconductor material layer (9), so as to form a residual conductive layer (9'), and subsequently by chemically removing the residual conductive layer (9'). In one application, the multi-layer wafer (8) is bonded to a first wafer (1) of semiconductor material, with the second semiconductor material layer (21) facing the first wafer (1), after micro-electromechanical structures (37) have been formed in the second semiconductor material layer (21) of the multi-layer wafer.
Abstract:
A semiconductor device includes a body (1) and, in the body (1): a semiconductor substrate (2), a semiconductor structural layer (10) and a dielectric layer (12) therebetween. A through interconnection via (30) traverses the body (1) and extends through the dielectric layer (12). The through interconnection via (30) has: a front-side interconnection region (17), including a portion of the structural layer (10) that extends between the dielectric layer (12) and a front face (10a) of the body (1) and is laterally insulated from the remainder of the structural layer (10); a back-side interconnection region (27), including a portion of the substrate (2) that extends between the dielectric layer (12) and a back face (2a) of the body (1) and is laterally insulated from the remainder of the substrate (2) by a back-side insulation trench (29). The back-side insulation trench (29) extends across the entire substrate (2; 102; 202), from the back face (2a) of the body (1) to the dielectric layer (12) the; and a conductive continuity region (8) connecting the front-side interconnection region (17) and the back-side interconnection region (27) through the dielectric layer (12).
Abstract:
The method is based on the use of a silicon carbide mask for removing a sacrificial region. In case of manufacture of integrated semiconductor material structures, the following steps are performed: forming a sacrificial region (6) of silicon oxide on a substrate (1) of semiconductor material; growing a pseudo-epitaxial layer (8); forming an electronic circuit (10-13, 18); depositing a silicon carbide layer (21); defining photolithographycally the silicon carbon layer so as to form an etching mask (23) containing the topography of a microstructure (27) to be formed; with the etching mask (23), forming trenches (25) in the pseudo-epitaxial layer (8) as far as the sacrificial region (6) so as to laterally define the microstructure; and removing the sacrificial region (6) through the trenches (25).
Abstract:
The angular speed sensor comprises a pair of mobile masses (2a, 2b) which are formed in the epitaxial layer (37) and are anchored to one another and to the remainder of the device by anchorage elements; the mobile masses are symmetrical with one another, and have mobile excitation electrodes (6a) which are intercalated with respective fixed excitation electrodes (7a 1 , 7a 2 ) and mobile detection electrodes (6b) which are intercalated with fixed detection electrodes (7b 1 , 7b 2 ). The mobile and fixed excitation electrodes extend in a first direction and the mobile and fixed detection electrodes extend in a second direction which is perpendicular to the first direction and is disposed on a single plane parallel to the surface of the device.
Abstract:
A pressure sensor (15) with double measuring scale, comprising: a flexible body (16, 34) designed to undergo deflection as a function of a said pressure (P); piezoresistive transducers (28, 29; 94) for detecting the deflection; a first focusing region (30) designed to concentrate, during a first operating condition, a first value (P INT1 ) of said pressure (P) in a first portion (19) of the flexible body (16, 34) so as to generate a deflection of the first portion (19) of the flexible body (16, 34); and a second focusing region (33) designed to concentrate, during a second operating condition, a second value (P INT2 ) of said pressure (P) in a second portion (17) of the flexible body (16, 34) so as to generate a deflection of the second portion (17) of the flexible body (16, 34). The piezoresistive transducers correlate the deflection of the first portion (19) of the flexible body (16, 34) to the first pressure value (P INT1 ) and the deflection of the second portion (17) of the flexible body (16, 34) to the second pressure value (P INT2 ).