Abstract:
The acoustic device has a micromachined acoustic transducer element (15); an acoustically attenuating region (40); and an acoustic matching region (32) arranged between the acoustic transducer element (15) and the acoustically attenuating region (40). The acoustic transducer element (15) is formed in a first substrate (25) housing a cavity (19) delimiting a membrane (16). A second substrate (30) of semiconductor material integrating an electronic circuit is arranged between the acoustic transducer element (15) and the acoustically attenuating region (40). The acoustic matching region (32) has a first interface (32A) with the second substrate (30) and a second interface (32B) with the acoustically attenuating region (40). The acoustic matching region (32) has an impedance matched to the impedance of the second substrate (30) in proximity of the first interface (32A), and an impedance matched to the acoustically attenuating region (40) in proximity of the second interface (32B).
Abstract:
A light-emitting device (1), comprising: a semiconductor body (2), having a first conductivity type, with a front side (2a) and a back side (2b); a porous-silicon region (10), which extends in the semiconductor body (2) at the front side (2a); and a cathode region (8) in direct lateral contact with the porous-silicon region (10). The light-emitting device further comprises a barrier region (12) of electrically insulating material, which extends in direct contact with the cathode region (8) at the bottom side of the cathode region so that in use an electric current flows in the semiconductor body exclusively through lateral portions of the cathode region (8).
Abstract:
A vertical-conduction semiconductor electronic device (40, comprising: a semiconductor body (1, 2); a body region (30) in the semiconductor body (1, 2); a source terminal (32) in the body region (30); a drain terminal (38) spatially opposite to the source region; and a trench gate (6, 14, 16', 24) extending in depth in the semiconductor body through the body region (30) and the source region (32). The trench gate includes a dielectric region (14) of porous silicon oxide buried in the semiconductor body, and a gate conductive region (24) extending between the dielectric region (14) of porous silicon oxide and said first side (2a).