Carbon-doped silicon single crystal wafer and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-11761118-B2
Application number	US-202017619516-A
Country	US
Kind code	B2
Filing date	Jun 30, 2020
Priority date	Jul 2, 2019
Publication date	Sep 19, 2023
Grant date	Sep 19, 2023

Abstract

A method for manufacturing a carbon-doped silicon single crystal wafer, including steps of: preparing a silicon single crystal wafer not doped with carbon; performing a first RTA treatment on the silicon single crystal wafer in an atmosphere containing compound gas; performing a second RTA treatment at a higher temperature than the first RTA treatment; cooling the silicon single crystal wafer after the second RTA treatment; and performing a third RTA treatment. The crystal wafer is modified to a carbon-doped silicon single crystal wafer, sequentially from a surface thereof: a 3C-SiC single crystal layer; a carbon precipitation layer; a diffusion layer of interstitial carbon and silicon; and a diffusion layer of vacancy and carbon. A carbon-doped silicon single crystal wafer having a surface layer with high carbon concentration and uniform carbon concentration distribution to enable wafer strength enhancement; and a method for manufacturing the carbon-doped silicon single crystal wafer.

First claim

The invention claimed is:

1. A method for manufacturing a carbon-doped silicon single crystal wafer, the method comprising steps of:
preparing a silicon single crystal wafer not doped with carbon;
performing a first RTA treatment on the silicon single crystal wafer in an atmosphere containing a carbon atom-containing compound gas;
performing a second RTA treatment successively after the first RTA treatment at a higher temperature than that in the first RTA treatment;
cooling the silicon single crystal wafer after the second RTA treatment; and
performing a third RTA treatment after the cooling, wherein
the silicon single crystal wafer is modified by these steps to form a carbon-doped silicon single crystal wafer comprising, sequentially from a surface thereof:
a 3C-SiC single crystal layer;
a carbon precipitation layer;
a diffusion layer of interstitial carbon and silicon; and
a diffusion layer of vacancy and carbon.

2. The method for manufacturing a carbon-doped silicon single crystal wafer according to claim 1 , further comprising a step of removing the 3C-SiC single crystal layer by polishing after the step of performing the third RTA treatment.

3. The method for manufacturing a carbon-doped silicon single crystal wafer according to claim 2 , wherein the carbon precipitation layer is controlled to have a carbon concentration of 3×10 17 atoms/cm 3 or more within a range from the surface of the carbon-doped silicon single crystal wafer to 0.14 μm.

4. The method for manufacturing a carbon-doped silicon single crystal wafer according to claim 2 , wherein the diffusion layer of interstitial carbon and silicon is controlled to have a carbon concentration of 1×10 17 atoms/cm 3 or more within a range of more than 0.14 μm and 1 μm or less away from the surface of the carbon-doped silicon single crystal wafer.

5. The method for manufacturing a carbon-doped silicon single crystal wafer according to claim 2 , wherein the diffusion layer of vacancy and carbon is controlled to have a carbon concentration of 1×10 16 atoms/cm 3 or more in a region deeper than 1 μm from the surface of the carbon-doped silicon single crystal wafer.

6. The method for manufacturing a carbon-doped silicon single crystal wafer according to claim 1 , wherein the silicon single crystal wafer to be prepared has an oxygen concentration of 11 ppma or more.

7. The method for manufacturing a carbon-doped silicon single crystal wafer according to claim 1 , wherein the silicon single crystal wafer to be prepared comprises any of an Nv region, an Ni region, and a V region.

8. The method for manufacturing a carbon-doped silicon single crystal wafer according to claim 1 , wherein the first and second RTA treatments are performed in a mixed atmosphere containing a hydrocarbon gas and one or both of Ar and H 2 .

9. The method for manufacturing a carbon-doped silicon single crystal wafer according to claim 1 , wherein
the first RTA treatment is performed at a temperature between 600° C. or more and 850° C. or less such that the temperature is maintained for a period of 5 seconds or more and 60 seconds or less,
the second RTA treatment is performed at a temperature between 1100° C. or more and silicon melting point or less such that the temperature is maintained for a period of 10 seconds or more and 150 seconds or less, and
the third RTA treatment is performed at a temperature between 1100° C. or more and silicon melting point or less such that the temperature is maintained for a period of 10 seconds or more and 150 seconds or less.

10. The method for manufacturing a carbon-doped silicon single crystal wafer according to claim 1 , wherein the third RTA treatment is repeated once or more times.

11. A carbon-doped silicon single crystal wafer comprising, sequentially from a surface of the silicon single crystal wafer:
a carbon precipitation layer;
a diffusion layer of interstitial carbon and silicon; and
a diffusion layer of vacancy and carbon.

12. The carbon-doped silicon single crystal wafer according to claim 11 , wherein the carbon precipitation layer has a carbon concentration of 3×10 17 atoms/cm 3 or more within a range from the surface of the carbon-doped silicon single crystal wafer to 0.14 μm.

13. The carbon-doped silicon single crystal wafer according to claim 11 , wherein the diffusion layer of interstitial carbon and silicon has a carbon concentration of 1×10 17 atoms/cm 3 or more within a range of more than 0.14 μm and 1 μm or less away from the surface of the carbon-doped silicon single crystal wafer.

14. The carbon-doped silicon single crystal wafer according to claim 11 , wherein the diffusion layer of vacancy and carbon has a carbon concentration of 1×10 16 atoms/cm 2 or more in a region deeper than 1 μm from the surface of the carbon-doped silicon single crystal wafer.

15. The carbon-doped silicon single crystal wafer according to claim 11 , further comprising a 3C-SiC single crystal layer on the carbon precipitation layer.

16. The carbon-doped silicon single crystal wafer according to claim 11 , wherein the carbon-doped silicon single crystal wafer has an oxygen concentration of 11 ppma or more.

17. The carbon-doped silicon single crystal wafer according to claim 11 , wherein the silicon single crystal wafer comprises any of an Nv region, an Ni region, and a V region.

Assignees

• Shinetsu Handotai Kk

Inventors

• Qu Weifeng
• Igawa Shizuo
• Sunakawa Ken

Classifications

• H10P90/12 Primary

  Preparing bulk and homogeneous wafers · CPC title

• H10P32/171

  being group IV material · CPC title

• H10P32/12

  between a solid phase and a gaseous phase · CPC title

• H10P95/90

  Thermal treatments, e.g. annealing or sintering · CPC title

• H10P30/20

  into semiconductor materials, e.g. for doping · CPC title