Silicon carbide schottky diode

• US 9,627,553 B2
• Filed: 02/05/2013
• Issued: 04/18/2017
• Est. Priority Date: 10/20/2005
• Status: Active Grant

• Current Assignee: Siliconix Technology CV (Vishay Intertechnology Incorporated)
• Original Assignee: Siliconix Technology CV (Vishay Intertechnology Incorporated)
• Inventors: Richieri, Giovanni
• Primary Examiner(s): Luu, Chuong A
• Application Number:
  US13/759,872
• Publication Number:
  US 20140042459A1
• Time in Patent Office: 1,533 Days
• Field of Search: 257676, 257155, 257260, 257267, 257280-284, 257449-457, 257471-474, 257 77, 257478, 257253
• CPC Class Codes: H01L 2224/05 of an individual bonding area
• CPC Class Codes: H01L 29/1608 Silicon carbide
• CPC Class Codes: H01L 29/47 Schottky barrier electrodes H01L29/435 takes precedence
• CPC Class Codes: H01L 29/872 Schottky diodes

Abstract

A SiC Schottky diode which includes a Schottky barrier formed on a silicon face 4H—SiC body.

Claims

1. A semiconductor device, comprising:

a SiC substrate;

a silicon face SiC epitaxial body formed on a first surface of a said SiC substrate;

a Schottky metal barrier formed on said silicon face of said SiC epitaxial body; and

a back power electrode on a second surface of said SiC substrate wherein said Schottky metal barrier is configured to exhibit a voltage characterization of the barrier that reflects uniformity between said Schottky metal barrier and said silicon.

2. The semiconductor device of claim 1, wherein said Schottky metal barrier is comprised of Titanium.

3. The semiconductor device of claim 1, wherein said back electrode is comprised of a stack of Titanium, Nickel, and Silver.

4. The semiconductor device of claim 1, a region of another conductivity diffused into said SiC epitaxial body defining an outer boundary of an active region of said device.

5. The semiconductor device of claim 1, further comprising a field insulation body formed on said SiC epitaxial body, wherein said Schottky metal barrier extends over said field insulation body.

6. The semiconductor device of claim 5, wherein said field insulation body is comprised of silicon dioxide.

7. The semiconductor device of claim 5, wherein said field insulation body includes tapered sidewalls tapering toward said SiC epitaxial body.

8. The semiconductor device of claim 1, further comprising a front power electrode formed on said Schottky metal body.

9. The semiconductor device of claim 8, wherein said front power electrode is comprised of aluminum.

10. The semiconductor device of claim 1, wherein said SiC epitaxial body is comprised of 4H—

SiC.

11. The semiconductor device of claim 10, wherein said SiC is comprised of 4H—

SiC.

12. A Schottky diode comprising:

a silicon face SiC epitaxial body; and

a Schottky metal barrier formed on said silicon face of said SiC epitaxial body,

wherein said Schottky metal barrier is configured to exhibit a voltage characterization of the barrier that reflects uniformity between said Schottky metal barrier and said silicon.

13. The Schottky diode of claim 12 further comprising:

a back electrode comprising Titanium, Nickel, and Silver.

14. The Schottky diode of claim 12 further comprising:

a region of another conductivity diffused into said SiC epitaxial body defining an outer boundary of an active region of said Schottky diode.

15. The Schottky diode of claim 14 wherein said region of another conductivity forms a guard ring around said active region.

16. The Schottky diode of claim 12 wherein said SiC comprises 4H SiC.

17. The Schottky diode of claim 12 further comprising a ring of silicon oxide disposed between a portion of said Schottky metal and said SiC epitaxial body.

18. The Schottky diode of claim 12 characterized as having an ideality factor of less than 1.1 for temperatures above 140 K.

19. The Schottky diode of claim 12 characterized as having an ideality factor of less than or equal to 1.05 for temperatures above 200 K.

20. The Schottky diode of claim 12 characterized as having a breakdown voltage of greater than 1100 volts.