Semiconductor device with field electrode structures in a cell area and termination structures in an edge area
A semiconductor device includes field electrode structures regularly arranged in lines in a cell area and forming a first portion of a regular pattern. Termination structures are formed in an inner edge area surrounding the cell area, wherein at least portions of the termination structures form a second portion of the regular pattern. Cell mesas separate neighboring ones of the field electrode structures from each other in the cell area and include first portions of a drift zone, wherein a voltage applied to a gate electrode controls a current flow through the cell mesas. At least one doped region forms a homojunction with the drift zone in the inner edge area.
1. A semiconductor device comprising:
field electrode structures arranged in a cell area and between gate structures, wherein the field electrode structures extend into a semiconductor body and form a first portion of a pattern;
termination structures formed in an inner edge area surrounding the cell area, wherein at least portions of the termination structures form a second portion of the pattern;
cell mesas separating neighboring ones of the field electrode structures from each other in the cell area; and
at least one doped region forming a homojunction with a drift zone in the inner edge area,
wherein each of the field electrode structures comprises a field electrode and a field dielectric separating the field electrode from the semiconductor body,
wherein each of the termination structures comprises a termination electrode and a termination dielectric separating the termination electrode from the semiconductor body.
2. The semiconductor device of claim 1 , wherein the at least one of said termination structures comprises first portions and second portions, the first portions and the field electrode structures arranged in lines and forming the pattern and each second portion connecting two of the first portions.
3. The semiconductor device of claim 1 , wherein at least one of the termination structures surrounds the cell area.
4. The semiconductor device of claim 1 , wherein a width of a termination mesa between a circumferential termination structure surrounding the cell area and neighboring termination structures or field electrode structures is uniform along a circumference.
5. The semiconductor device of claim 1 , wherein the termination and field electrode structures are arranged in lines and form the pattern.
6. The semiconductor device of claim 1 , wherein the at least one doped region is arranged between termination structures and is configured to float.
7. The semiconductor device of claim 1 , wherein the at least one doped region forms a pn junction with the drift zone.
8. The semiconductor device of claim 1 , wherein the at least one doped region is depletable in an operational mode of the semiconductor device.
9. The semiconductor device of claim 1 , wherein the at least one doped region forms a unipolar homojunction with the drift zone and a mean net dopant concentration in the drift zone is at least twice as high as a mean net dopant concentration in the at least one doped region.
10. The semiconductor device of claim 1 , wherein the termination structures extend from a first surface into the semiconductor body and wherein the at least one doped region is arranged as a vertical projection of the termination structures and forms a pn junction with the drift zone.
11. The semiconductor device of claim 10 , wherein the at least one doped region is depletable in an operational mode of the semiconductor device.
12. The semiconductor device of claim 1 , wherein each of said termination structures comprises insulating material and/or intrinsic semiconducting materials.
13. The semiconductor device of claim 1 , wherein the at least one doped region directly adjoins a respective termination electrode.
14. The semiconductor device of claim 1 , wherein the at least one doped region is formed between the termination structures, forms a pn junction with the drift zone and is electrically connected to a termination electrode of the termination structures, wherein the at least one doped region is closer to the cell area than the termination electrode.
15. The semiconductor device of claim 1 , wherein the field electrode and termination structures have a same width.
16. The semiconductor device of claim 1 , wherein a vertical extension of the termination structures is greater than a vertical extension of the field electrode structures.
17. The semiconductor device of claim 1 , wherein a width of a circumferential termination structure is smaller than a lateral extension of the field electrode structures.