Method for Manufacturing Silicon Wafer and Silicon Wafer Manufactured by this Method

• US 20080118424A1
• Filed: 06/21/2005
• Published: 05/22/2008
• Est. Priority Date: 06/30/2004
• Status: Active Grant

• Current Assignee: Sumco Corporation
• Original Assignee: Sumco Corporation
• Inventors: Sugimura, Wataru, Hourai, Masataka, Sadamitsu, Shinsuke, Akatsuka, Masanori
• Granted Patent: US 7,700,394 B2
• Time in Patent Office: Days
• US Class Current: 423/324
• CPC Class Codes: C30B 29/06 Silicon
• CPC Class Codes: C30B 33/02 Heat treatment C30B33/04, C30B33/06 take precedence
• CPC Class Codes: H01L 21/3225 Thermally inducing defects using oxygen present in the silicon body for intrinsic gettering H01L21/3226 takes precedence
• CPC Class Codes: H01L 21/3226 of silicon on insulator

Abstract

There is obtained a silicon wafer which has a large diameter, where no slip generated therein in a wide range of a density of oxygen precipitates even though a heat treatment such as SLA or FLA is applied thereto, and which has high strength.

First, by inputting as input parameters combinations of a plurality of types of oxygen concentrations and thermal histories set for manufacture of a silicon wafer a Fokker-Planck equation is solved to calculate each of a diagonal length L and a density D of oxygen precipitates in the wafer after a heat treatment step to form the oxygen precipitates (11) and immediately before a heat treatment step of a device manufacturing process is calculated. Then, a maximum heat stress S acting in a tangent line direction of an outer peripheral portion of the wafer in the heat treatment step of the device manufacturing process is calculated based on a heat treatment furnace structure and a heat treatment temperature used in the heat treatment step of the device manufacturing process, and then an oxygen concentration or the like satisfying the following Expression (1) is determined:

12000×D^−0.26≦L≦51000×S^−1.55   (1)

Claims

1. A method for manufacturing a silicon wafer, produced by slicing a silicon single-crystal rod to obtain a wafer (10), subjecting the wafer to a first heat treatment to form oxygen precipitates (11, 21, 31) therein, and then subjecting the silicon wafer (10) having the oxygen precipitates (11, 21, 31) formed therein a second heat treatment in a semiconductor device manufacturing process, the method for manufacturing the silicon wafer comprising:

setting a plurality of types of oxygen concentrations and thermal histories for manufacture of the wafer (10);

calculating each of a diagonal length L (nm) and a density D (pieces/cm³) of the oxygen precipitates (11, 21, 31) in the wafer (10) after the first heat treatment step to form the oxygen precipitates (11, 21, 31) and immediately before the second heat treatment step of the device manufacturing process by solving a Fokker-Planck equation with using respective combinations of the plurality of types of oxygen concentrations and thermal histories as input parameters;

calculating a maximum heat stress S (MPa) acting in a tangent line direction of an outer peripheral portion of the wafer (10) in the second heat treatment step of the device manufacturing process based on a structure and a second heat treatment temperature of a second heat treatment furnace used in the second heat treatment step of the device manufacturing process; and

determining an oxygen concentration and a thermal history satisfying a the following Expression (1) in the plurality of types of oxygen concentrations and thermal histories;

12000×

D<sup>−

0.26</sup>≦

L≦

51000×

S<sup>−

1.55</sup> 

 

(1)

2. The method of claim 1, further comprising setting a plurality of concentrations of a dopant selected from a group consisting of B, P, As and Sb in the silicon wafer (10) adding these dopant concentrations to the input parameters.

3. The method of claim 1, further comprising setting a plurality of carbon concentrations in the silicon wafer (10), and adding these carbon concentrations to the input parameters.

4. The method of claim 2 further comprising setting a plurality of carbon concentrations in the silicon wafer (10) and adding these carbon concentrations to the input parameters.

5. The method of claim 1, further comprising setting a plurality of nitrogen concentrations in the silicon wafer (10) and adding these nitrogen concentrations to the input parameters.

6. The method of claim 2 further comprising setting a plurality of nitrogen concentrations in the silicon wafer (10) and adding these nitrogen concentrations to the input parameters.

7. The method of claim 3 further comprising setting a plurality of nitrogen concentrations in the silicon wafer (10) and adding these nitrogen concentrations to the input parameters.

8. The method of claim 4 further comprising setting a plurality of nitrogen concentrations in the silicon wafer (10) and adding these nitrogen concentrations to the input parameters.

9. The method of claim 1 wherein the first heat treatment is carried out by increasing the temperature at a fixed temperature increasing speed from a temperature in the range from 600 to 1000°

C.

10. The method of claim 1 wherein the first heat treatment is carried out at a temperature in the range from 500°

C. to 1000°

C.

11. A silicon wafer manufactured by the method of claim 1.

12. A silicon wafer manufactured by the method of claim 2.

13. A silicon wafer manufactured by the method of claim 3.

14. A silicon wafer manufactured by the method of claim 5.

15. A silicon wafer manufactured by the method of claim 6.

16. A silicon wafer manufactured by the method of claim 6.

17. A silicon wafer manufactured by the method of claim 7.

18. A silicon wafer manufactured by the method of claim 8.

19. A silicon wafer manufactured by the method of claim 9.

20. A silicon wafer manufactured by the method of claim 10.