Silicon carbide semiconductor component

Patent metadata

Field	Value
Publication number	US-11437470-B2
Application number	US-201916415365-A
Country	US
Kind code	B2
Filing date	May 17, 2019
Priority date	May 18, 2018
Publication date	Sep 6, 2022
Grant date	Sep 6, 2022

Abstract

The disclosure relates to a semiconductor component having an SiC semiconductor body and a first load terminal on a first surface of the SiC semiconductor body. A second load terminal is formed on a second surface of the SiC semiconductor body opposite the first surface. The semiconductor component has a drift zone of a first conductivity type in the SiC semiconductor body and a first semiconductor area of a second conductivity type which is electrically connected to the first load terminal. A pn junction between the drift zone and the first semiconductor area defines a voltage blocking strength of the semiconductor component.

First claim

What is claimed is:

1. A semiconductor component, comprising:
an SiC semiconductor body;
a first load terminal on a first surface of the SiC semiconductor body;
a second load terminal on a second surface of the SiC semiconductor body opposite the first surface;
a drift zone of a first conductivity type in the SiC semiconductor body;
a first semiconductor area of a second conductivity type which is electrically connected to the first load terminal;
a second semiconductor area of the second conductivity type between at least part of the drift zone and the second surface,
a third semiconductor area of the first conductivity type which is formed between the second semiconductor area and the second surface and forms an interface with the second semiconductor area; and
a fourth semiconductor area of the first conductivity type that laterally adjoins the third semiconductor area and is disposed below the interface;
a fifth semiconductor area of the first conductivity type that is disposed between the third semiconductor area and the second surface,
wherein a pn junction between the drift zone and the first semiconductor area defines a voltage blocking strength of the semiconductor component,
wherein dopants in the second semiconductor area have deep defects, the energy gap of which from a closest band edge is more than 160 meV,
and
wherein a net doping in the second semiconductor area is greater than in the fourth semiconductor area,
wherein a net doping in the third semiconductor area is greater than in the fifth semiconductor area,
wherein the semiconductor component further comprises scatter sites configured to reduce charge carrier mobility in the third semiconductor area, and
wherein the fourth semiconductor area is devoid of the scatter sites.

2. The semiconductor component of claim 1 , wherein the second semiconductor area has a maximum lateral extent within a range from 500 nm to 300 μm.

3. The semiconductor component of claim 1 , wherein the second semiconductor area has a vertical extent within a range from 20 nm to 1 μm.

4. The semiconductor component of claim 1 , wherein the semiconductor component is a unipolar semiconductor component.

5. The semiconductor component of claim 4 , wherein the unipolar semiconductor component is a merged PIN Schottky (MPS) diode, a Schottky diode, a field-effect transistor (FET), or a junction FET.

6. The semiconductor component of claim 1 , wherein the voltage blocking strength is within a range from 400 V to 15 kV.

7. The semiconductor component of claim 1 , wherein the semiconductor component is a power semiconductor component having a specified current-carrying capacity between the first load terminal and the second load terminal of at least 1 A.

8. The semiconductor component of claim 1 , wherein the dopants comprise one or more elements selected from the group of elements consisting of aluminum, boron, gallium, chromium, and iridium.

9. The semiconductor component of claim 1 , wherein the semiconductor component has a plurality of the second semiconductor areas, and wherein an area proportion of the plurality of second semiconductor areas in relation to an active area of the semiconductor component is within a range from 10% to 50%.

10. The semiconductor component of claim 1 , wherein the second semiconductor area is buried in the SiC semiconductor body in an electrically floating arrangement at a vertical distance from the second surface.

11. The semiconductor component of claim 1 , wherein a maximum lateral extent of the third semiconductor area corresponds to a maximum lateral extent of the second semiconductor area.

12. The semiconductor component of claim 1 , wherein a maximum lateral extent of the third semiconductor area is less than a maximum lateral extent of the second semiconductor area.

13. The semiconductor component of claim 1 , wherein the third semiconductor area has a vertical extent within a range from 20 nm to 1.5 μm.

14. The semiconductor component of claim 1 , wherein the scatter sites comprise lattice defects.

15. The semiconductor component of claim 1 , wherein dopants in the third semiconductor area comprise deep defects, the energy gap of which to a closest band edge is more than 160 meV.

16. The semiconductor component of claim 1 , wherein the first conductivity type is n-type.

17. The semiconductor component of claim 16 , wherein dopants in the drift zone comprise defects having an energy gap from a conduction band edge of less than 140 meV.

18. The semiconductor component of claim 1 , wherein the semiconductor component has a plurality of the second semiconductor areas, wherein a ratio of minimum lateral distance between adjacent ones of the second semiconductor areas and minimum lateral extent of the second semiconductor area is within a range from 0.1 to 20.

19. The semiconductor component of claim 1 , wherein a dopant concentration of the fifth semiconductor area is between 5×10 17 cm −3 to 5×10 18 cm −3 .

20. The semiconductor component of claim 1 , further comprising a sixth semiconductor area of the first conductivity type between the drift zone and the second semiconductor area, wherein a dopant concentration of the sixth semiconductor area is between 5×10 17 cm −3 to 5×10 18 cm −3 .

Assignees

• Infineon Technologies Ag

Inventors

• Basler Thomas
• Elpelt Rudolf
• Schulze Hans-Joachim

Classifications

• H10D30/66

  Vertical DMOS [VDMOS] FETs · CPC title

• H10D62/405

  Orientations of crystalline planes · CPC title

• H10D30/668

  having trench gate electrodes, e.g. UMOS transistors · CPC title

• H10D30/80

  FETs having rectifying junction gate electrodes (H10D30/40 takes precedence) · CPC title

• H10D8/60

  Schottky-barrier diodes · CPC title