Stripe-shaped electrode structure including a main portion with a field electrode and an end portion terminating the electrode structure

Patent metadata

Field	Value
Publication number	US-9837498-B2
Application number	US-201615166957-A
Country	US
Kind code	B2
Filing date	May 27, 2016
Priority date	May 28, 2015
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

A semiconductor device includes a stripe-shaped electrode structure that extends from a first surface into a semiconductor portion. The electrode structure includes a main portion and an end portion terminating the electrode structure. The main portion includes a field electrode and a first portion of a field dielectric separating the field electrode from the semiconductor portion. The end portion includes a filled section in which a second portion of the field dielectric extends from a first side of the electrode structure to an opposite second side. The filled section is narrower than the main portion and a length of the filled section along a longitudinal axis of the electrode structure is at least 150% of a first layer thickness of the first portion of the field dielectric.

First claim

What is claimed is:

1. A semiconductor device, comprising:
a stripe-shaped electrode structure extending from a first surface into a semiconductor portion, wherein the electrode structure comprises a main portion and an end portion terminating the electrode structure,
wherein the main portion comprises a field electrode and a first portion of a field dielectric separating the field electrode from the semiconductor portion,
wherein the end portion comprises a filled section in which a second portion of the field dielectric extends from a first side of the electrode structure to an opposite second side,
wherein the filled section is narrower than the main portion and a length of the filled section along a longitudinal axis of the electrode structure is at least 150% of a first layer thickness of the first portion of the field dielectric,
wherein the end portion is devoid of a gate electrode and a gate contact.

2. The semiconductor device of claim 1 , wherein the filled section comprises a narrow section of uniform width and narrower than the main portion.

3. The semiconductor device of claim 2 , wherein a width of the narrow section is at most twice the first layer thickness of the first portion of the field dielectric in the main portion.

4. The semiconductor device of claim 1 , wherein the end portion includes a tapering section sandwiched between the filled section and the main portion, and a width of the tapering section continuously decreases from the main portion to the filled portion.

5. The semiconductor device of claim 1 , wherein the end portion includes an expanded section directly adjoining the filled section at a side opposite to the main portion, wherein a width of the expanded section is greater than a width of the filled section.

6. The semiconductor device of claim 1 , wherein with respect to the first surface, a vertical extension of the filled section is smaller than a vertical extension of the electrode structure in the main portion.

7. The semiconductor device of claim 1 , wherein the field dielectric comprises a thermally grown layer directly adjoining the semiconductor portion.

8. The semiconductor device of claim 1 , wherein the filled section tapers with increasing distance to the main portion.

9. The semiconductor device of claim 1 , wherein the main portion comprises a gate electrode and a separation dielectric separating the gate electrode and the field electrode.

10. The semiconductor device of claim 9 , further comprising a signal processing circuit electrically connected or coupled to the gate electrode.

11. The semiconductor device of claim 1 , wherein the semiconductor portion includes transistor cells that comprise body zones forming first pn junctions with a drift zone and second pn junctions with source zones, and wherein the body zones separate the drift zone from the source zones.

12. The semiconductor device of claim 11 , wherein the body zones and the source zones are formed in mesa sections between the electrode structures and wherein the electrode structures extend into the drift zone.

13. The semiconductor device of claim 1 , wherein a length of the filled section along the longitudinal axis of the electrode structure is at least 200% of the first layer thickness.

14. An electronic circuit, comprising:
a semiconductor device comprising:
a stripe-shaped electrode structure extending from a first surface into a semiconductor portion, wherein the electrode structure comprises a main portion and an end portion terminating the electrode structure,
wherein the main portion comprises a field electrode and a first portion of a field dielectric separating the field electrode from the semiconductor portion,
wherein the end portion comprises a filled section in which a second portion of the field dielectric extends from a first side of the electrode structure to an opposite second side,
wherein the filled section is narrower than the main portion and a length of the filled section along a longitudinal axis of the electrode structure is at least 150% of a first layer thickness of the first portion of the field dielectric,
wherein the end portion is devoid of a gate electrode and a gate contact; and
a load electrically coupled to a load electrode of the semiconductor device.

15. The electronic circuit of claim 14 , further comprising a gate control circuit electrically connected or coupled to an input terminal of the semiconductor device and configured to control a switching cycle of the semiconductor device.

16. The semiconductor device of claim 1 , wherein the end portion is occupied entirely by the second portion of the field dielectric so that the end portion is devoid of electrically conductive material.

17. The semiconductor device of claim 4 , wherein the field electrode extends into and narrows within the tapering section.

18. The semiconductor device of claim 5 , wherein the expanded section includes a conductive material.

19. The semiconductor device of claim 5 , wherein the end portion includes a first tapering section sandwiched between the filled section and the main portion and a second tapering section sandwiched between the filled section and the expanded section, wherein a width of the first tapering section continuously decreases from the main portion to the filled portion, and wherein a width of the second tapering section continuously increases from the filled portion to the expanded section.

20. The semiconductor device of claim 19 , wherein the field electrode extends into and narrows within the first tapering section.

21. The semiconductor device of claim 1 , wherein the main portion extends deeper into the semiconductor portion than the end portion.

Assignees

• Infineon Technologies Ag

Inventors

• Schwetlick Werner
• Zink Robert

Classifications

• H01L29/42368

  Electricity · mapped topic

• H01L29/407 Primary

  Electricity · mapped topic

• H01L29/401

  Electricity · mapped topic

• H01L27/0922

  Electricity · mapped topic

• H01L29/4238

  Electricity · mapped topic