Power semiconductor component

• US 20050116287A1
• Filed: 09/15/2004
• Published: 06/02/2005
• Est. Priority Date: 09/15/2003
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Mauder, Anton, Falck, Elmar
• Granted Patent: US 7,291,899 B2
• Time in Patent Office: Days
• US Class Current: 257/341
• CPC Class Codes: H01L 29/0661 specially adapted for altering the breakdown voltage by removing semiconductor material at, or in the neighbourhood of, a reverse biased junction, e.g. by bevelling, moat etching, depletion etching
• CPC Class Codes: H01L 29/861 Diodes

Abstract

A semiconductor component suitable for use as a power semiconductor component and method of making a semiconductor component is disclosed. In one embodiment, the semiconductor component includes a semiconductor body having a first surface, a second surface, a third surface, a first conduction type region and a second conduction type region adjoining the first conduction type region at the third surface. A trench extending from the first surface into the semiconductor body, the trench defined by a trench bottom and an arcuately shaped sidewall.

Claims

1. A semiconductor component comprising:

a semiconductor body having a first surface, a second surface, a third surface, a first conduction type region and a second conduction type region adjoining the first conduction type region at the third surface;

a trench extending from the first surface into the semiconductor body, the trench defined by a trench bottom and an arcuately shaped sidewall.

2. The semiconductor component of claim 1, where the first conduction type region is n conduction type, and the second conduction type region is p conduction type.

3. The semiconductor component of claim 1, comprising:

a second trench extending from the trench bottom into the first conductive type region, having a second trench sidewall.

4. The semiconductor component of claim 3, comprising:

an insulation layer applied to the arcuately shaped sidewall and the second trench sidewall.

5. The semiconductor component of claim 4, where the insulation layer at least partially extends over the first surface.

6. The semiconductor component of claim 5, comprising an electrically conductive layer in contact with the second conduction type region.

7. The semiconductor component of claim 6, where the electically conductive layer partially extends over the insulation layer, including the arcuately shaped sidewall.

8. The semiconductor component of claim 7, comprising:

a second electrically conductive layer applied to the second surface of the semiconductor body, in contact with the first conduction type region.

9. The semiconductor component of claim 8, comprising:

a second insulation material, where the trench and the second trench are filled with the second insulation material and the second insulation material at least partially extends over the electrically conductive layer.

10. The semiconductor component of claim 9, where the second insulation material is a polyamide.

11. The semiconductor component of claim 9, the second trench having a second trench bottom, where the electrically conductive layer is deposited on the second trench bottom.

12. The semiconductor component of claim 9, comprising a barrier layer positioned above the insulation layer.

13. The semiconductor component of claim 1, where the semiconductor component functions as a diode.

14. A power semiconductor component having an edge structure, comprising:

a semiconductor body of a first conduction type with a first and a second surface, a region of a second conduction type that adjoins the first surface and is arranged in the semiconductor body, and a trench extending from the first surface into the semiconductor body with a sidewall adjoining the semiconductor body and with a trench bottom, an insulator layer applied on the trench walls and on regions adjoining the trench on the surface of the semiconductor body, and an electrically conductive layer that is applied on parts of the insulator layer and makes contact with parts of the first region of the second conduction type, wherein the sidewall merges arcuately concavely with the trench bottom, and wherein a further trench is arranged in the trench bottom.

15. The power semiconductor component of claim 14, comprising:

an electrically conductive layer applied on the second surface of the semiconductor body and makes contact with the semiconductor body of the first conduction type.

16. The power semiconductor component of claim 15, wherein the trench and the further trench are filled with a second electrically insulating material, and also covers regions of the electrically conductive layer on the first surface of the semiconductor body.

17. The power semiconductor component of claim 16, comprising a barrier layer arranged above the insulator layer.

18. The power semiconductor component of claim 17, where the barrier layer is made of silicon nitride.

19. The power semiconductor component of claim 17, where the trench bottom lies at least 20% further away from the first surface of the semiconductor body than the junction between the region of a second conduction type and the semiconductor body of a first conduction type.

20. The power semiconductor component of claims 14, wherein the power semiconductor component is a transistor.

21. A method for fabricating a power semiconductor component, comprising:

providing a semiconductor substrate of a first conduction type with a first and a second surface and a doped region of a second conduction type that adjoins the first semiconductor surface and is arranged in the semiconductor body;

masking and patterning an edge of the power semiconductor component;

forming a first trench at the component edge with a sidewall that merges arcuately concavely with the trench bottom, including by means of and isotropic trench etching;

forming a second trench penetrating through the trench bottom within the first trench removing the masking;

producing an oxide at the free surfaces of the power semiconductor component;

masking and etching the contact regions of the first semiconductor surface;

removing the masking;

depositing an electrically conductive layer on the first semiconductor surface and on parts of the first and second trenches; and

depositing an electrically conductive layer on the second surface of the semiconductor body.

22. The method of claim 21, in which a silicon nitride layer is deposited onto the oxide layer on the free surfaces of the power semiconductor component.

23. The method of claim 22, in which, after the deposition of the electrically conductive layer on the first semiconductor surface and on parts of the first and second trenches, comprising:

filling the first and second trenches with polyimide; and

patterning the polyimide.

24. The method of claim 21, in which, before the deposition of the electrically conductive layer on the second surface of the semiconductor body, comprising:

introducing a contact and/or emitter implantation into the second surface of the semiconductor body.