Thyristor and method of manufacture
View Patent ↗A thyristor and a method for manufacturing the thyristor that includes a gate region extending from the first major surface into a semiconductor substrate and an anode region extending from the second major surface into the semiconductor substrate. A cathode region extends into a portion of the gate region. Optionally, enhanced doped regions extend into the gate and anode regions. A mesa structure having a height H G is formed from the first major surface and a mesa structure having a height H A is formed from the second major surface. The gate region extends under the first major surface of the semiconductor substrate and it extends vertically into the semiconductor substrate a distance that is greater than height H G . The anode region extends under the second major surface of the semiconductor substrate and it extends vertically into the semiconductor substrate a distance that is greater than height H A .
1. A thyristor, comprising:
a semiconductor substrate of a second conductivity type having first and second sides;
a first mesa structure extending from the first side, the first mesa structure having a mesa surface and first and second sidewalls, the first sidewall of the first mesa structure extending from a first portion of the first side to the mesa surface of the first mesa structure and the second sidewall of the first mesa structure extending from a second portion of the first side to the mesa surface of the first mesa structure;
a second mesa structure extending from the second side, the second mesa structure having a mesa surface and first and second sidewalls, the first sidewall of the second mesa structure extending from a first portion of the second side to the mesa surface of the second mesa structure and the second sidewall of the second mesa structure extending from a second portion of the second side to the mesa surface of the second mesa structure;
a first doped region of a first conductivity type in the first mesa structure, wherein the first doped region has a first boundary laterally spaced apart from the first sidewall and a second boundary laterally spaced apart from the second sidewall, wherein the first doped region laterally extends beyond the first mesa structure and extends to the mesa surface of the first mesa structure; and
a second doped region of a first conductivity type in the second mesa structure, wherein the second doped region has a first boundary laterally spaced apart from the first sidewall and a second boundary laterally spaced apart from the second sidewall, wherein the first doped region laterally extends beyond the first mesa structure and extends to the mesa surface of the second mesa structure.
2. The thyristor of claim 1 , wherein the first and second sidewalls of the first mesa structure and the first and second sidewalls of the second mesa structure have a concave shape.
3. The thyristor of claim 1 , wherein the first doped region extends from the mesa surface of the first mesa structure into the semiconductor substrate a distance that is greater than a height of the first mesa structure.
4. The thyristor of claim 1 , further including a third doped region within the first doped region.
5. The thyristor of claim 4 , wherein the first and second doped regions are of a first conductivity type and the third doped region is of a second conductivity type.
6. The thyristor of claim 5 , wherein the first conductivity type is P-type conductivity and the second conductivity type is N-type conductivity.
7. The thyristor of claim 4 , further including an enhanced doped region of the first conductivity type within the second doped region.
8. The thyristor of claim 1 , further including a first dielectric material disposed over the first sidewall of the first mesa structure, a portion of the mesa surface of the first mesa structure, and a subportion of the first portion of the first side.
9. The method of claim 8 , further including a second dielectric material disposed over the first sidewall of the second mesa structure, a portion of the mesa surface of the second mesa structure, and a subportion of the first portion of the second side.
10. The thyristor of claim 1 , further including first, second, and third contacts, the first contact in contact with the first doped region, the second contact in contact with the second doped region, and the third contact in contact with the third doped region.
11. A thyristor, comprising:
a semiconductor substrate having first and second sides;
a first mesa structure extending from a first portion of the first side, the first mesa structure having a mesa surface and first and second sidewalls, the first sidewall of the first mesa structure extending from the first portion of the first side to the mesa surface of the first mesa structure and the second sidewall of the first mesa structure extending from the second portion of the first side to the mesa surface of the first mesa structure;
a second mesa structure extending from the second side, the second mesa structure having a mesa surface and first and second sidewalls, the first sidewall of the second mesa structure extending from a first portion of the second side to the mesa surface of the second mesa structure and the second sidewall of the second mesa structure extending from a second portion of the second side to the mesa surface of the second mesa structure;
a first doped region in the first mesa structure, wherein the first doped region has a first subportion that extends from the first portion of the first side to the mesa surface of the first mesa structure and a second subportion that extends from the second portion of the first side to the mesa surface of the first mesa structure;
a third doped region within the first doped region, wherein the first and second doped regions are of a first conductivity type and the third doped region is of a second conductivity type;
a first enhanced doped region of the first conductivity type within the first doped region, wherein the first enhanced doped region is spaced apart from the third doped region; and
a second doped region in the second mesa structure, wherein the second doped region has a first subportion that extends from the first portion of the second side to the mesa surface of the second mesa structure and a second subportion that extends from the second portion of the second side to the mesa surface of the second mesa structure.
12. The thyristor of claim 11 , further including a second enhanced doped region of the first conductivity type within the second doped region.
13. A bidirectional semiconductor component, comprising:
a semiconductor substrate having first and second surfaces;
a first mesa structure extending from the first surface, the first mesa structure having a mesa surface, a sidewall, and a height;
a gate region within the first mesa structure, the gate region extending from the first surface to the mesa surface of the first mesa structure a distance that is greater than the height of the first mesa structure;
a second mesa structure extending from the second surface, the second mesa structure having a mesa surface, a sidewall, and a height;
an anode region within the second mesa structure, the anode region extending from the second surface to the mesa surface of the second mesa structure a distance that is greater than the height of the second mesa structure; and
a cathode region within the gate region.
14. The bidirectional semiconductor component of claim 13 , wherein the sidewall of the first mesa structure and the sidewall of the second mesa structure are concave.
15. The bidirectional semiconductor component of claim 13 , further including an enhanced doped region disposed in the gate region, the enhanced doped region disposed in the gate region being of the same conductivity type as the gate region.
16. The bidirectional semiconductor component of claim 15 , further including an enhanced doped region disposed in the anode region, the enhanced doped region disposed in the anode region being of the same conductivity type as the anode region.
17. The bidirectional semiconductor component of claim 13 , wherein the gate region has P-type conductivity, the cathode region has N-type conductivity, and the anode region has P-type conductivity.
18. The bidirectional semiconductor component of claim 13 , wherein the gate region extends under the first surface and the anode region extends under the second surface.