IP Library › Granted Patent US 8,872,307
Granted Patent B2
US 8,872,307 · App. 13/610,940 · Granted Oct 28, 2014

P-type silicon single crystal and method of manufacturing the same

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Quick Facts
Patent No.
US 8,872,307
App. No.
13/610,940
Granted
Oct 28, 2014
Kind
B2
Abstract

Silicon wafers having a resistivity >6 Ωcm and axially uniform resistivity are grown by the Czochralski method from a melt containing boron as the main dopant, an n-type first sub-dopant with a segregation coefficient lower than boron, and a p-type second sub-dopant with a segregation coefficient lower than the first sub-dopant.

Claims (69)

1. A method of manufacturing a p-type silicon single crystal, comprising the steps of:

preparing a silicon melt to which boron as a main dopant, a first sub-dopant which is an n-type impurity with a smaller segregation coefficient than boron, and a second sub-dopant which is a p-type impurity with a smaller segregation coefficient than the first sub-dopant are added; and

growing a silicon single crystal having resistivity not lower than 6 Ωcm from the silicon melt by the Czochralski method.

2. The method of manufacturing a p-type silicon single crystal of claim 1 , wherein

the first sub-dopant is phosphorus and the second sub-dopant is aluminum, and

a first concentration ratio calculated by dividing the concentration of the first sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 0.5 and not higher than 1.2 and a second concentration ratio calculated by dividing the concentration of the second sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 4.9 and not higher than 52.4.

3. The method of manufacturing a p-type silicon single crystal of claim 1 , wherein

the first sub-dopant is phosphorus and the second sub-dopant is gallium, and

a first concentration ratio calculated by dividing the concentration of the first sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 0.5 and not higher than 1.2 and a second concentration ratio calculated by dividing the concentration of the second sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 1.2 and not higher than 13.4.

4. The method of manufacturing a p-type silicon single crystal of claim 1 , wherein

the first sub-dopant is phosphorus and the second sub-dopant is indium, and

a first concentration ratio calculated by dividing the concentration of the first sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 0.5 and not higher than 1.2 and a second concentration ratio calculated by dividing the concentration of the second sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 25.1 and not higher than 261.2.

5. The method of manufacturing a p-type silicon single crystal of claim 1 , wherein

the first sub-dopant is arsenic and the second sub-dopant is aluminum, and

a first concentration ratio calculated by dividing the concentration of the first sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 0.6 and not higher than 1.5 and a second concentration ratio calculated by dividing the concentration of the second sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 11.7 and not higher than 72.2.

6. The method of manufacturing a p-type silicon single crystal of claim 1 , wherein

the first sub-dopant is arsenic and the second sub-dopant is gallium, and

a first concentration ratio calculated by dividing the concentration of the first sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 0.6 and not higher than 1.5 and a second concentration ratio calculated by dividing the concentration of the second sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 3.1 and not higher than 18.3.

7. The method of manufacturing a p-type silicon single crystal of claim 1 , wherein

the first sub-dopant is arsenic and the second sub-dopant is indium, and

a first concentration ratio calculated by dividing the concentration of the first sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 0.6 and not higher than 1.4 and a second concentration ratio calculated by dividing the concentration of the second sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 57.9 and not higher than 324.0.

8. The method of manufacturing a p-type silicon single crystal of claim 1 , wherein

the first sub-dopant is phosphorus and the second sub-dopant is aluminum, and

a first concentration ratio calculated by dividing the concentration of the first sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 0.79 and not higher than 0.81 and a second concentration ratio calculated by dividing the concentration of the second sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 24.2 and not higher than 27.0.

9. The method of manufacturing a p-type silicon single crystal of claim 1 , wherein

the first sub-dopant is phosphorus and the second sub-dopant is aluminum, and

a first concentration ratio calculated by dividing the concentration of the first sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 0.89 and not higher than 0.91 and a second concentration ratio calculated by dividing the concentration of the second sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 30.8 and not higher than 33.8.

10. The method of manufacturing a p-type silicon single crystal of claim 1 , wherein

the first sub-dopant is phosphorus and the second sub-dopant is gallium, and

a first concentration ratio calculated by dividing the concentration of the first sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 0.79 and not higher than 0.81 and a second concentration ratio calculated by dividing the concentration of the second sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 6.2 and not higher than 6.9.

11. The method of manufacturing a p-type silicon single crystal of claim 1 , wherein

the first sub-dopant is phosphorus and the second sub-dopant is gallium, and

a first concentration ratio calculated by dividing the concentration of the first sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 0.89 and not higher than 0.91 and a second concentration ratio calculated by dividing the concentration of the second sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 7.8 and not higher than 8.5.

12. A p-type silicon single crystal which is grown from a silicon melt by the method of claim 1 , comprising:

boron as a main dopant;

a first sub-dopant which is an n-type impurity and smaller in segregation coefficient than the boron; and

a second sub-dopant which is a p-type impurity and smaller in segregation coefficient than the first sub-dopant,

the p-type silicon single crystal having a resistivity which is not lower than 6 Ωcm.

13. The p-type silicon single crystal of claim 12 , wherein

the first sub-dopant is phosphorus and the second sub-dopant is aluminum, and

a first concentration ratio calculated by dividing the concentration of the first sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 0.5 and not higher than 1.2 and a second concentration ratio calculated by dividing the concentration of the second sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 4.9 and not higher than 52.4.

14. The p-type silicon single crystal of claim 12 , wherein

the first sub-dopant is phosphorus and the second sub-dopant is gallium, and

a first concentration ratio calculated by dividing the concentration of the first sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 0.5 and not higher than 1.2 and a second concentration ratio calculated by dividing the concentration of the second sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 1.2 and not higher than 13.4.

15. The p-type silicon single crystal of claim 12 , wherein

the first sub-dopant is phosphorus and the second sub-dopant is indium, and

a first concentration ratio calculated by dividing the concentration of the first sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 0.5 and not higher than 1.2 and a second concentration ratio calculated by dividing the concentration of the second sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 25.1 and not higher than 261.2.

16. The p-type silicon single crystal of claim 12 , wherein

the first sub-dopant is arsenic and the second sub-dopant is aluminum, and

a first concentration ratio calculated by dividing the concentration of the first sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 0.6 and not higher than 1.5 and a second concentration ratio calculated by dividing the concentration of the second sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 11.7 and not higher than 72.2.

17. The p-type silicon single crystal of claim 12 , wherein

the first sub-dopant is arsenic and the second sub-dopant is gallium, and

a first concentration ratio calculated by dividing the concentration of the first sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 0.6 and not higher than 1.5 and a second concentration ratio calculated by dividing the concentration of the second sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 3.1 and not higher than 18.3.

18. The p-type silicon single crystal of claim 12 , wherein

the first sub-dopant is arsenic and the second sub-dopant is indium, and

a first concentration ratio calculated by dividing the concentration of the first sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 0.6 and not higher than 1.4 and a second concentration ratio calculated by dividing the concentration of the second sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 57.9 and not higher than 324.0.

19. The p-type silicon single crystal of claim 12 , wherein

the first sub-dopant is phosphorus and the second sub-dopant is aluminum, and

a first concentration ratio calculated by dividing the concentration of the first sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 0.79 and not higher than 0.81 and a second concentration ratio calculated by dividing the concentration of the second sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 24.2 and not higher than 27.0.

20. The p-type silicon single crystal of claim 12 , wherein

the first sub-dopant is phosphorus and the second sub-dopant is aluminum, and

a first concentration ratio calculated by dividing the concentration of the first sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 0.89 and not higher than 0.91 and a second concentration ratio calculated by dividing the concentration of the second sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 30.8 and not higher than 33.8.

21. The p-type silicon single crystal of claim 12 , wherein

the first sub-dopant is phosphorus and the second sub-dopant is gallium, and

a first concentration ratio calculated by dividing the concentration of the first sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 0.79 and not higher than 0.81 and a second concentration ratio calculated by dividing the concentration of the second sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 6.2 and not higher than 6.9.

22. The p-type silicon single crystal of claim 12 , wherein

the first sub-dopant is phosphorus and the second sub-dopant is gallium, and

a first concentration ratio calculated by dividing the concentration of the first sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 0.89 and not higher than 0.91 and a second concentration ratio calculated by dividing the concentration of the second sub-dopant in the silicon melt by the concentration of the main dopant in the silicon melt is not lower than 7.8 and not higher than 8.5.

23. A silicon wafer obtained by slicing a p-type silicon single crystal of claim 12 .

Assignments (3)
CORRECTIVE ASSIGNMENT TO CORRECT THE DATE OF THE CHANGE OF ADDRESS FROM 03/12/2020 TO 12/03/2020 PREVIOUSLY RECORDED AT REEL: 056719 FRAME: 0881. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT. Recorded Jul 1, 2021
From: SILTRONIC AG
To: SILTRONIC AG
Reel/Frame 057561/0451 →
CHANGE OF ADDRESS Recorded Jun 30, 2021
From: SILTRONIC AG
To: SILTRONIC AG
Reel/Frame 056719/0881 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 12, 2012
From: NAKAI, KATSUHIKO
To: SILTRONIC AG
Reel/Frame 028940/0397 →