IP Library Granted Patent US 11,069,778
Granted Patent B2
US 11,069,778 · App. 16/111,810 · Granted Jul 20, 2021

Silicon carbide components and methods for producing silicon carbide components

Inventors: Roland Rupp (Lauf, DE); Ronny Kern (Finkenstein, AT)
Assignee: Infineon Technologies AG
H01L29/1608H01L21/02378H01L21/02529H01L21/02694H01L21/046H01L21/268H01L21/304H01L21/7813H01L29/0615H01L29/6606H01L29/66068H01L21/26506H01L29/7395H01L29/7827H01L29/872
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Quick Facts
Patent No.
US 11,069,778
App. No.
16/111,810
Granted
Jul 20, 2021
Kind
B2
Abstract

A method for producing a silicon carbide component includes forming a silicon carbide layer on an initial wafer, forming a doping region of the silicon carbide component to be produced in the silicon carbide layer, and forming an electrically conductive contact structure of the silicon carbide component to be produced on a surface of the silicon carbide layer. The electrically conductive contact structure electrically contacts the doping region. Furthermore, the method includes splitting the silicon carbide layer or the initial wafer after forming the electrically conductive contact structure, such that a silicon carbide substrate at least of the silicon carbide component to be produced is split off.

Claims (47)

1. A method for producing a silicon carbide component, the method comprising:

forming a silicon carbide layer on an initial wafer;

forming a doping region of the silicon carbide component to be produced in the silicon carbide layer;

forming an electrically conductive contact structure of the silicon carbide component to be produced on a surface of the silicon carbide layer, the electrically conductive contact structure electrically contacting the doping region;

splitting at least one from the silicon carbide layer and the initial wafer after forming the electrically conductive contact structure, such that a silicon carbide substrate at least of the silicon carbide component to be produced is split off; and

forming a passivation layer on the surface of the silicon carbide layer before the splitting, wherein the electrically conductive contact structure is disposed within an opening in the passivation layer.

2. The method of claim 1 , wherein the silicon carbide substrate split off has a thickness of more than 30 μm.

3. The method of claim 1 , wherein the doping region is formed to extend to a surface of the silicon carbide layer.

4. The method of claim 1 , wherein a portion of the surface of the silicon carbide layer is not covered electrically conductive contact structure.

5. A method for producing a silicon carbide component, the method comprising:

forming a silicon carbide layer on an initial wafer;

forming a doping region of the silicon carbide component to be produced in the silicon carbide layer;

forming an electrically conductive contact structure on the surface of the silicon carbide layer, the electrically conductive contact structure electrically contacting the doping region,

producing a pre-damaged splitting region, wherein the splitting region is produced by:

(i) implanting ions into the initial wafer or the silicon carbide layer, wherein an absorption coefficient of the pre-damaged splitting region for laser radiation in a known wavelength range is at least 5 times an absorption coefficient in a region of the initial wafer or the silicon carbide layer outside the pre-damaged splitting region; or

(ii) laser treating the splitting region before forming the electrically conductive contact structure in order to pre-damage the splitting region;

splitting the silicon carbide layer or the initial wafer along the splitting region after forming the doping region, such that a silicon carbide substrate at least of the silicon carbide component to be produced is split off, wherein the silicon carbide substrate has a thickness of more than 30 μm,

wherein the doping region is formed to extend to a surface of the silicon carbide layer before splitting the silicon carbide layer, and

wherein splitting along the splitting region comprises at least one of:

(i) applying a polymer film;

(ii) producing thermal stress; and

(iii) irradiating the initial wafer or the silicon carbide layer with laser radiation in a known wavelength range.

6. The method of claim 5 , wherein at least one surface of the initial wafer comprises silicon carbide, and wherein forming the silicon carbide layer comprises epitaxially growing silicon carbide on the surface of the initial wafer.

7. The method of claim 5 , wherein forming the silicon carbide layer comprises:

forming a first partial layer of the silicon carbide layer with an average doping concentration of more than 5*10 17 cm −3 ; and

forming a second partial layer of the silicon carbide layer with an average doping concentration of less than 1*10 17 cm −3 .

8. The method of claim 7 , wherein the thickness of the first partial layer of the silicon carbide layer is greater than 20 μm.

9. The method of claim 7 , wherein the thickness of the second partial layer of the silicon carbide layer is less than 30 μm.

10. The method of claim 7 , wherein the thickness of the second partial layer of the silicon carbide layer is less than the thickness of the first partial layer of the silicon carbide layer.

11. The method of claim 7 , wherein at least one part of the second partial layer forms a drift region of the silicon carbide component to be produced.

12. The method of claim 5 , further comprising:

forming a passivation layer on the surface of the silicon carbide layer before the splitting.

13. The method of claim 5 , further comprising:

securing a carrier wafer or a carrier film to a layer stack formed on the surface of the silicon carbide layer, before the splitting.

14. The method of claim 5 , further comprising:

conditioning a surface of a remaining wafer, comprising at least one part of the initial wafer, after the splitting.

15. The method of claim 14 , further comprising:

forming a further silicon carbide layer on the remaining wafer;

forming a doping region of a further silicon carbide component to be produced in the further silicon carbide layer; and

splitting the further silicon carbide layer or the remaining wafer after forming the doping region of the further silicon carbide component to be produced, such that a further silicon carbide substrate at least of the further silicon carbide component to be produced is split off.

16. The method of claim 5 , wherein the splitting is carried out by implanting ions or laser bombardment into a splitting region in the silicon carbide layer or the initial wafer.

17. The method of claim 5 , wherein the splitting comprises splitting the silicon carbide layer such that a part of the silicon carbide layer remains on the initial wafer after the splitting.

18. The method of claim 5 , further comprising:

forming an electrically conductive contact structure of the silicon carbide component to be produced on the surface of the silicon carbide layer, the electrically conductive contact structure electrically contacting the doping region,

wherein the electrically conductive contact structure comprises at least one of metal and polysilicon.

19. The method of claim 5 , further comprising:

separating the silicon carbide layer in regions between silicon carbide components to be produced before the splitting.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 19, 2018
From: RUPP, ROLAND; KERN, RONNY
To: INFINEON TECHNOLOGIES AG
Reel/Frame 046905/0756 →
Priority Claims (1)
DE 102017119568.8 · Aug 25, 2017 · national
Continuity (1)
Related Publication 20190067425A1 · Feb 28, 2019
Cited By (2)
US 12,302,619 US 12,594,622