SEMICONDUCTOR COMPONENT INCLUDING AN EDGE TERMINATION HAVING A TRENCH AND METHOD FOR PRODUCING

• US 20090008723A1
• Filed: 07/02/2008
• Published: 01/08/2009
• Est. Priority Date: 07/02/2007
• Status: Active Grant

• Current Assignee: Infineon Technologies Austria Ag (Infineon Technologies AG)
• Original Assignee: Infineon Technologies Austria Ag (Infineon Technologies AG)
• Inventors: Schmidt, Gerhard
• Granted Patent: US 8,093,676 B2
• Time in Patent Office: Days
• US Class Current: 257/409
• CPC Class Codes: H01L 21/26586 characterised by the angle between the ion beam and the crystal planes or the main crystal surface
• CPC Class Codes: H01L 23/3178 Coating or filling in grooves made in the semiconductor body
• CPC Class Codes: H01L 29/0638 for preventing surface leakage due to surface inversion layer, e.g. with channel stopper channel stoppers in combination with isolation region for integrated circuits H01L21/762
• 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 29/0692 Surface layout
• CPC Class Codes: H01L 29/41766 with at least part of the source or drain electrode having contact below the semiconductor surface, e.g. the source or drain electrode formed at least partially in a groove or with inclusions of conductor inside the semiconductor H01L29/41733 - H01L29/41758 take precedence
• CPC Class Codes: H01L 29/66136 PN junction diodes
• CPC Class Codes: H01L 29/6634 with a recess formed by etching in the source/emitter contact region H01L29/66348 takes precedence; etching of semiconductor bodies H01L21/302
• CPC Class Codes: H01L 29/66727 with a step of recessing the source electrode
• CPC Class Codes: H01L 29/7396 with a non planar surface, e.g. with a non planar gate or with a trench or recess or pillar in the surface of the emitter, base or collector region for improving current density or short circuiting the emitter and base regions H01L29/7398 takes precedence
• CPC Class Codes: H01L 29/7811 with an edge termination structure guard regions per se H01L29/0619; field plates per se H01L29/402
• CPC Class Codes: H01L 29/8613 Mesa PN junction diodes
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/13055 Insulated gate bipolar transistor [IGBT]
• CPC Class Codes: H01L 2924/13091 Metal-Oxide-Semiconductor Field-Effect Transistor [MOSFET]

Abstract

A semiconductor component includes a semiconductor body having a first side, a second side, an edge delimiting the semiconductor body in a lateral direction, an inner region and an edge region. A first semiconductor zone of a first conduction type is arranged in the inner region and in the edge region. A second semiconductor zone of a second conduction type is arranged in the inner region and adjacent to the first semiconductor zone. A trench is arranged in the edge region and has first and second sidewalls and a bottom, and extends into the semiconductor body. A doped first sidewall zone of the second conduction type is adjacent to the first sidewall of the trench. A doped second sidewall zone of the second conduction type is adjacent to the second sidewall of the trench. A doped bottom zone of the second conduction type is adjacent to the bottom of the trench. Doping concentrations of the sidewall zones are lower than a doping concentration of the bottom zone.

Claims

1. A semiconductor component comprising:

a semiconductor body having a first side, a second side, an edge delimiting the semiconductor body in a lateral direction, and also having an inner region and an edge region arranged between the inner region and the edge in the lateral direction;

a first semiconductor zone of a first conduction type, which is arranged in the inner region and in the edge region;

a second semiconductor zone of a second conduction type complementary to the first conduction type, which is arranged in the inner region and which is adjacent to the first semiconductor zone in a direction of the first side;

a trench arranged in the edge region and having first and second sidewalls and a bottom, which extends into the semiconductor body proceeding from the first side; and

a doped first sidewall zone of the second conduction type, which is adjacent to the first sidewall of the trench, a doped second sidewall zone of the second conduction type, which is adjacent to the second sidewall of the trench, and a doped bottom zone of the second conduction type, which is adjacent to the bottom of the trench, and which is arranged within the first semiconductor zone, wherein doping concentrations of the sidewall zones are lower than a doping concentration of the bottom zone.

2. The semiconductor component of claim 1, further comprising a connection zone of the first or second conduction type that is doped more highly than the first semiconductor zone and is adjacent to the first semiconductor zone in a direction of the second side.

3. The semiconductor component of claim 1, further comprising a third semiconductor zone of the first conduction type, adjacent to the first semiconductor zone in the edge region in a direction of the first side, doped more highly than the first semiconductor zone and extending in the lateral direction from the trench or the second sidewall zone as far as the edge.

4. The semiconductor component of claim 1, wherein a dopant dose of the sidewall zones in a direction perpendicular to the sidewalls of the trench is less than or equal to 1·

1012 cm−

2.

5. The semiconductor component of claim 1, wherein a dopant dose of the bottom zone in a direction perpendicular to the bottom of the trench is greater than 1·

1012 cm−

2.

6. The semiconductor component of claim 1, wherein the following holds true for a difference between a dopant dose of the bottom zone and the dopant dose of the sidewall zones:

0.5·

ND·

d≦

Δ

DP≦

2·

ND·

d,

where DP denotes the dopant does difference, ND denotes the dopant concentration of the first semiconductor zone and d denotes the distance between the bottom zone and the connection zone.

7. The semiconductor component of claim 1, wherein the first and second sidewall zones adjoin the bottom zone.

8. The semiconductor component of claim 1, configured as a MOS transistor, wherein the first semiconductor zone forms a drift zone, the second semiconductor zone forms a body zone and the connection zone forms a drain zone, and which further comprises:

a source zone of the first conduction type, separated from the drift zone by the body zone; and

a gate electrode for controlling a channel in the body zone between the source zone and the drift zone, arranged adjacent to the body zone and which is dielectrically insulated from the body zone.

9. The semiconductor component of claim 8, wherein the drain zone is of the same conduction type as the drift zone.

10. The semiconductor component of claim 8, wherein the drain zone is of a complementary conduction type with respect to the conduction type of the drift zone.

11. The semiconductor component of claim 1, configures as a diode, wherein the first semiconductor zone forms a base zone and the second semiconductor zone forms a first emitter zone, and wherein the connection zone is of the same conduction type as the first semiconductor zone but doped more highly and forms a second emitter zone.

12. A method for producing an edge termination of a semiconductor component, comprising:

providing a semiconductor body having a first side, a second side, an edge delimiting the semiconductor body in a lateral direction, and also having an inner region and an edge region arranged between the inner region and the edge in the lateral direction, and having a first semiconductor zone of a first conduction type, arranged in the inner region and in the edge region;

producing a trench arranged in the edge region, which trench has at least one elongated trench section having first and second sidewalls and a bottom and extends into the first semiconductor zone proceeding from the first side;

carrying out a first oblique implantation, by means of which dopant atoms of a complementary conduction type with respect to the first conduction type are implanted into the first sidewall and in which an implantation angle is chosen such that dopant atoms are implanted over the entire area of the first sidewall but not into the bottom of the trench;

carrying out a second oblique implantation, by means of which dopant atoms of a complementary conduction type with respect to the first conduction type are implanted into the first sidewall and in which an implantation angle is chosen such that dopant atoms are implanted over the entire area of the first sidewall but not into the bottom of the trench; and

carrying out at least one further implantation, by means of which dopant atoms of the first conduction type are implanted into the bottom of the trench.

13. The method of claim 12, wherein the further implantation is a third oblique implantation, the implantation direction of which in a lateral direction of the semiconductor body deviates by approximately 90°

from implantation directions of the first and second oblique implantations.

14. The method of claim 13, wherein a fourth oblique implantation is carried out for implanting dopants into the bottom of the trench, the implantation direction of the fourth oblique implantation in a lateral direction of the semiconductor body deviating by approximately 180°

from the implantation direction of the third oblique implantation.

15. The method of claim 12, wherein the trench is produced such that it rectangularly encloses the inner region and has four straight trench sections, of which a first and a third trench section and a second and a fourth trench section respectively run at least approximately parallel, wherein, by means of the first and second oblique implantations, dopants are implanted into the sidewalls of the first and second trench sections and into the bottom of the third and fourth trench sections and, by means of the third and fourth oblique implantations, dopants are implanted into the sidewalls of the third and fourth trench sections and into the bottom of the first and second trench sections.

16. A semiconductor component comprising:

a semiconductor body having a first side, a second side, an edge delimiting the semiconductor body in a lateral direction, an inner region and an edge region arranged between the inner region and the edge in the lateral direction;

a first semiconductor zone of a first conduction type arranged in the inner region and in the edge region;

a second semiconductor zone of a second conduction type complementary to the first conduction type arranged in the inner region and adjacent the first semiconductor zone;

a trench extending into the semiconductor body and arranged in the edge region, the trench having first and second sidewalls and a bottom; and

means within the trench for providing an electric field strength that is lower in the region of the trench than in the inner region of the semiconductor body.

17. The semiconductor component of claim 16, further comprising a doped first sidewall zone of the second conduction type adjacent the first sidewall of the trench, a doped second sidewall zone of the second conduction type adjacent the second sidewall of the trench, and a doped bottom zone of the second conduction type adjacent the bottom of the trench.

18. The semiconductor component of claim 17, wherein doping concentrations of the sidewall zones are lower than a doping concentration of the bottom zone.

19. The semiconductor component of claim 18, further comprising a connection zone of the first or second conduction type that is doped more highly than the first semiconductor zone and is adjacent to the first semiconductor zone in a direction of the second side.

20. The semiconductor component of claim 19, further comprising a third semiconductor zone of the first conduction type, adjacent to the first semiconductor zone in the edge region in a direction of the first side, doped more highly than the first semiconductor zone and extending in the lateral direction from the trench or the second sidewall zone as far as the edge.