Four-quadrant triac

1. A vertical four-quadrant triac wherein a gate region, arranged on a side of a front surface, comprises a U-shaped region of a first conductivity type, a base of the U-shaped region lying towards one side of a structure of the triac, a main front surface region of a second conductivity type extending in front of the gate region and being surrounded with portions of a main front surface region of the first conductivity type, wherein the gate region is located at the middle of said one side of the structure of the triac and is located closer to said one side than to an opposite side of the structure of the triac.

2. The triac of claim 1 , wherein two portions of the main front surface region of the first conductivity type join in an area of the first conductivity type separating the gate region from the main front surface region of the second conductivity type.

3. The triac of claim 2 , wherein a region of the second conductivity type is maintained between said area of the first conductivity type and the gate region.

4. The triac of claim 1 , wherein a main rear surface region of the first conductivity type extends under the main front surface region of the second conductivity type and under a portion of the gate region.

5. The triac of claim 1 , wherein the first conductivity type is type N and the second conductivity type is type P.

6. A vertical four-quadrant triac comprising:

a first layered structure;

a second layered structure side-by-side with the first layered structure; and

a gate structure in contact with the first and second layered structures, the gate structure including a U-shaped region of a first conductivity type, wherein the vertical four-quadrant triac has a substantially square contour and wherein the gate structure is located at the middle of one side of the square contour and is located closer to said one side of the square contour than to an opposite side of the square contour.

7. A vertical four-quadrant triac as defined in claim 1 , wherein the first layered structure includes a main front surface region of a second conductivity type in front of the gate structure.

8. A vertical four-quadrant triac as defined in claim 7 , wherein the second layered structure includes a main front surface region of the first conductivity type on opposite sides of the gate structure and the main front surface region of the second conductivity type.

9. A vertical four-quadrant triac as defined in claim 8 , wherein the main front surface region of the first conductivity type comprises a substantially H-shaped region.

10. A vertical four-quadrant triac as defined in claim 9 , wherein the H-shaped region includes two arms and a central bar, wherein the central bar is located between the U-shaped region of the gate structure and the main front surface region of the second conductivity type.

11. A vertical four-quadrant triac as defined in claim 10 , wherein the gate structure is located between the two arms of the H-shaped region.

12. A vertical four-quadrant triac as defined in claim 8 , wherein the main front surface region of the second conductivity type and the main front surface region of the first conductivity type have substantially the same surface areas.

13. A vertical four-quadrant triac as defined in claim 8 , further comprising a main rear surface region of the first conductivity type under the main front surface region of the second conductivity type and under at least a portion of the gate structure.

14. A vertical four-quadrant triac as defined in claim 1 , wherein the gate structure further comprises a region of the second conductivity type inside the U-shaped region of the first conductivity type.