SCHOTTKY DIODE WITH REDUCED FORWARD VOLTAGE

• US 20150144966A1
• Filed: 11/20/2014
• Published: 05/28/2015
• Est. Priority Date: 11/26/2013
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Konrath, Jens Peter, Rupp, Roland, Schulze, Hans-Joachim
• Granted Patent: US 9,859,383 B2
• Time in Patent Office: Days
• US Class Current: 257/77
• CPC Class Codes: H01L 29/1608 Silicon carbide
• CPC Class Codes: H01L 29/36 characterised by the concentration or distribution of impurities in the bulk material within semiconductor regions H01L29/06
• CPC Class Codes: H01L 29/66143 Schottky diodes
• CPC Class Codes: H01L 29/872 Schottky diodes

Abstract

A semiconductor component includes a semiconductor body of a first conduction type and a metal layer on the semiconductor body, wherein the metal layer forms with the semiconductor body a Schottky contact along a contact surface. A doping concentration of the first conduction type on the contact surface varies along a direction of the contact surface.

Claims

1. A semiconductor component, comprising:

a semiconductor body of a first conduction type; and

a metal layer on the semiconductor body, wherein the metal layer forms with the semiconductor body a Schottky contact along a contact surface,

wherein a doping concentration of the first conduction type on the contact surface varies along a direction of the contact surface.

2. The semiconductor component as claimed in claim 1, wherein the doping concentration of the first conduction type on the contact surface varies along a direction of the contact surface in such a way that at least one more heavily doped region, which has heavier doping than a drift zone of the semiconductor component, is formed on the contact surface.

3. The semiconductor component as claimed in claim 2, wherein the doping concentration of the first conduction type on the contact surface varies stepwise along a direction of the contact surface.

4. The semiconductor component as claimed in claim 2, wherein the doping concentration of the first conduction type on the contact surface varies continuously along a direction of the contact surface.

5. The semiconductor component as claimed in claim 2, wherein the doping concentration of the first conduction type on the contact surface varies along a direction of the contact surface in such a way that a multiplicity of more heavily doped regions, which have heavier doping than a drift zone of the semiconductor component, are formed on the contact surface.

6. The semiconductor component as claimed in claim 3, wherein between at least two of the more heavily doped regions the contact surface has a doping concentration which corresponds to a doping concentration of the drift zone of the semiconductor body.

7. The semiconductor component as claimed in claim 2, wherein the at least one more heavily doped region has a depth of approximately 1 μ

m or less in a direction perpendicular to the contact surface.

8. The semiconductor component as claimed in claim 2, wherein the semiconductor body comprises silicon carbide (SiC), and wherein the at least one more heavily doped region has a depth of approximately 100 nm or less in a direction perpendicular to the contact surface.

9. The semiconductor component as claimed in claim 1, furthermore comprising at least one region of the second conduction type on the contact surface.

10. The semiconductor component as claimed in claim 9, wherein the region of the second conduction type has a greater depth in a direction perpendicular to the contact surface than the at least one more heavily doped region has.

11. The semiconductor component as claimed in claim 9, wherein the at least one more heavily doped region is arranged in an intermediate space between two regions of the second conduction type, and the lateral extent of the at least one more heavily doped region comprises less than ⅓

of the intermediate space.

12. The semiconductor component as claimed in claim 1, furthermore comprising at least one buried region of the second conduction type, which is buried in the semiconductor body.

13. The semiconductor component as claimed in claim 1, wherein the metal layer for forming the Schottky contact comprises at least one of Au, Pt, Cu, Ni, Ti, TiW, Mo, Ti_xN_y, Mo_xN_y, Pd, Mn, Al, Ag.

14. A semiconductor component, comprising:

a semiconductor body of a first conduction type;

a metal layer on the semiconductor body, wherein the metal layer forms with the semiconductor body a Schottky contact along a contact surface;

at least one region of the second conduction type on the contact surface, and

a region with increased doping concentration on the contact surface, in which the doping concentration of the first conduction type is greater than a doping concentration of the semiconductor body.

15. The semiconductor component as claimed in claim 14, wherein the region of the second conduction type and the region on the contact surface, in which the doping concentration of the first conduction type is greater than a doping concentration of the semiconductor body, are arranged on the contact surface.

16. The semiconductor component as claimed in claim 15, wherein the doping concentration of the first conduction type on the contact surface varies along a direction of the contact surface in such a way that at least one more heavily doped region, which has heavier doping than a drift zone of the semiconductor component, is formed on the contact surface.

17. The semiconductor component as claimed in claim 15, wherein the doping concentration of the first conduction type on the contact surface varies stepwise along a direction of the contact surface.

18. The semiconductor component as claimed in claim 15, wherein the doping concentration of the first conduction type on the contact surface varies continuously along a direction of the contact surface.

19. The semiconductor component as claimed in claim 15, wherein the metal layer for forming the Schottky contact comprises at least one of Au, Pt, Cu, Ni, Ti, TiW, Mo, Ti_xN_y, Mo_xN_y, Pd, Mn, Al, Ag.