Edge termination for semiconductor devices

1. A high-voltage termination structure, comprising:

a peripheral voltage-spreading network, comprising one or more trench structures connected at least partly in series between first and second voltages;

said trench structures respectively comprising current-limiting structures which are connected in series with a semiconductor material, and which include intentionally introduced net permanent charge in a trench-wall dielectric,

wherein said current-limiting structures, in combination with said semiconductor material, provide a voltage distribution of the difference between said first and second voltages.

2. The structure of claim 1 , wherein said first and second voltages are power supply voltages.

3. The structure of claim 1 , wherein said semiconductor material is silicon.

4. The structure of claim 1 , wherein at least one said current-limiting structure comprises a junction diode.

5. The structure of claim 1 , wherein said peripheral voltage-spreading network completely surrounds a core portion which includes active semiconductor devices.

6. The structure of claim 1 , wherein said permanent charge in said sidewalls is sufficient to cause inversion of at least one adjacent portion of semiconductor material.

7. The structure of claim 1 , wherein said trench structures respectively comprise first and second current-limiting structures connected in series with a semiconductor material, wherein the first and second current-limiting structures comprise diodes.

8. The structure of claim 7 , wherein said semiconductor material is silicon.

9. A high-voltage device termination structure, comprising:

a patterned combination of at least one first structure which conducts lateral current with one or more second structures which do not conduct lateral current;

said first structure being laterally confined, by said second structures, to define a continuous path from a core portion to an edge portion, which is more than three times as long as the direct distance from said core portion to said edge portion;

whereby the conductivity of said first structure defines a voltage distribution between said core portion and said edge portion.

10. The device of claim 9 , further comprising permanent charge positioned within said second structure, wherein said permanent charge induces leakage paths primarily along structure edges.

11. The device of claim 9 , wherein said edge portion is a device edge.

12. The device of claim 9 , wherein said core portion comprises at least one effective device.

13. The device of claim 9 , wherein said second structures include a plurality of trenches containing a solid dielectric.

14. The device of claim 9 , wherein said second structures include a plurality of dielectric trenches, and at least one of said dielectric trenches is wider than the other dielectric trenches.

15. A semiconductor device, comprising:

a core portion which controls passage of current between at least two terminals;

and an edge portion which includes a peripheral voltage-spreading network, comprising one or more trench structures connected at least partly in series between first and second terminals;

said trench structures respectively comprising current-limiting structures which are connected in series with a semiconductor material, and which include intentionally introduced permanent net charge in a trench-wall dielectric,

wherein said current-limiting structures, in combination with said semiconductor material, provide a voltage distribution between said core portion and said edge portion.

16. The device of claim 15 , wherein said core portion includes permanent charge, at one or more interfaces.

17. The device of claim 15 , wherein said edge portion is a device edge.

18. The device of claim 15 , wherein said core portion comprises at least one effective device.

19. The device of claim 15 , wherein said second structures include a plurality of dielectric trenches, and at least one of said dielectric trenches is wider than the other dielectric trenches.