Abstract: The invention concerns an asymmetric diac comprising a highly-doped substrate (21) of a first type of conductivity, a lightly-doped epitaxial layer (22) of the second type of conductivity on the upper surface of the substrate (21), a highly-doped region (24) of the first type of conductivity on the side of the upper surface of the epitaxial layer, a region (23) of the second type of conductivity more doped than the epitaxial layer beneath the region (24) of the first type of conductivity and not overlapping relative thereto, a channel retaining ring (25) of the second type of conductivity more doped than the epitaxial layer, outside the first region, and a wall (26) of the first type of conductivity outside said ring, joining the substrate.

Abstract: A structure formed in a semiconductor substrate having at least one area having a high concentration of atoms of a metal such as platinum or gold, in which the area is surrounded with at least one first trench penetrating into the substrate.

Abstract: The invention concerns at disc comprising a highly-doped substrate (20) of a first type of conductivity, a lightly-doped epitaxial layer (22) of the second type of conductivity including in the neighbourhood of the substrate (20) a more highly-doped part (21), a highly-doped region (24) of the first type of conductivity on the side of the upper surface of the epitaxial layer, a region (23) of the second type of conductivity more doped than the epitaxial layer beneath the region (24) of the first type of conductivity and not overlapping relative thereto, a channel retaining ring (25) of the second type of conductivity more highly doped than the epitaxial layer, outside the first region, a wall (26) of the first type of conductivity outside said ring, joining the substrate.

Abstract: A structure formed in a semiconductor substrate having at least one area having a high concentration of atoms of a metal such as platinum or gold, in which the area is surrounded with at least one first trench penetrating into the substrate.

Abstract: The invention concerns at diac comprising a highly-doped substrate (20) of a first type of conductivity, a lightly-doped epitaxial layer (22) of the second type of conductivity including in the neighbourhood of the substrate (20) a more highly-doped part (21), a highly-doped region (24) of the first type of conductivity on the side of the upper surface of the epitaxial layer, a region (23) of the second type of conductivity more doped than the epitaxial layer beneath the region (24) of the first type of conductivity and not overlapping relative thereto, a channel retaining ring (25) of the second type of conductivity more highly doped than the epitaxial layer, outside the first region, a wall (26) of the first type of conductivity outside said ring, joining the substrate.

Abstract: The invention concerns an asymmetric diac comprising a highly-doped substrate (21) of a first type of conductivity, a lightly-doped epitaxial layer (22) of the second type of conductivity on the upper surface of the substrate (21), a highly-doped region (24) of the first type of conductivity on the side of the upper surface of the epitaxial layer, a region (23) of the second type of conductivity more doped than the a epitaxial layer beneath the region (24) of the first type of conductivity and not overlapping relative thereto, a channel retaining ring (25) of the second type of conductivity more doped than the epitaxial layer, outside the first region, and a wall (26) of the first type of conductivity outside said ring, joining the substrate.

Abstract: In a method for etching a deep groove in a silicon substrate, an oxide mask is delineated according to the shape of the desired groove. The photoresist which served to form the oxide mask is removed. A new photoresist layer is deposited and etched to define a photoresist mask overlapping the edges of the oxide mask. The wafer is immersed into a chemical bath for etching the silicon to form the desired groove, partially extending beneath the oxide mask. After rinsing, the wafter is immersed into a chemical bath for etching the silicon oxide to remove the oxide cap lying over the groove and a portion of the oxide layer projecting over the substrate beyond the edges of the groove.