Soi wafer and its manufacturing method

• US 20070032043A1
• Filed: 09/08/2004
• Published: 02/08/2007
• Est. Priority Date: 09/08/2003
• Status: Active Grant

• Current Assignee: Sumco Corporation
• Original Assignee: Sumco Corporation
• Inventors: Morimoto, Nobuyuki, Endo, Akihiko
• Granted Patent: US 7,713,838 B2
• Time in Patent Office: Days
• US Class Current: 438/459
• CPC Class Codes: H01L 21/322 to modify their internal properties, e.g. to produce internal imperfections
• 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 21/76254 with separation/delamination along an ion implanted layer, e.g. Smart-cut, Unibond

Abstract

Since a supporting wafer contains boron of 9×10¹⁸ atoms/cm³ or more, therefore a part of the metal impurities in an active layer wafer and the metal impurities in the wafer can be captured by the boron during the heat treatment for bonding. As a result, metal contamination in the active layer can be reduced. Moreover, the wafer strength is enhanced, thus preventing the wafer slipping. Since the wafer has no COP, micro voids are not detected in the LPD evaluation of the active layer, thereby improving the reliability of the evaluation. Such a bonded wafer can be manufactured at a low cast.

Claims

1. A manufacturing method of an SOI wafer, comprising the steps of:

bonding a wafer for active layer with a supporting wafer via an insulating film interposed therebetween to thereby form a bonded wafer; and

then

reducing a film thickness in a part of said active layer wafer of said bonded wafer to thereby form an SOI layer for manufacturing said SOI wafer, wherein

said supporting wafer contains boron by an amount of 9×

10¹⁸ atoms/cm³ or more.

2. A manufacturing method of an SOI wafer in accordance with claim 1, further comprising the steps of:

ion-implanting of hydrogen gas or a noble gas element to said active layer wafer to thereby form an ion-implanted layer in said active layer wafer;

subsequently bonding said active layer wafer and said supporting wafer together to thereby form a bonded wafer; and

then

heat treating said bonded wafer to thereby induce cleavage in said bonded wafer at the site of said ion-implanted layer as an interface.

3. A manufacturing method of an SOI wafer in accordance with claim 1, in which a thickness of said SOI layer is 0.10 μ

m or thinner.

4. A manufacturing method of an SOI wafer in accordance with claim 2, in which a thickness of said SOI layer is 0.10 μ

m or thinner.

5. A manufacturing method of an SOI wafer in accordance with claim 1, in which an insulating film is formed at least on a surface opposite to a bonding surface of said supporting wafer before said step of bonding.

6. A manufacturing method of an SOI wafer in accordance with claim 2, in which an insulating film is formed at least on a surface opposite to a bonding surface of said supporting wafer before said step of bonding.

7. A manufacturing method of an SOI wafer in accordance with claim 3, in which an insulating film is formed at least on a surface opposite to a bonding surface of said supporting wafer before said step of bonding.

8. A manufacturing method of an SOI wafer in accordance with claim 4, in which an insulating film is formed at least on a surface opposite to a bonding surface of said supporting wafer before said step of bonding.

9. A manufacturing method of an SOI wafer in accordance with claim 1, in which said supporting wafer is subjected to annealing at 1100°

C. or higher in a reducing gas atmosphere containing hydrogen gas before said step of bonding.

11. A manufacturing method of an SOI wafer in accordance with claim 2, in which said supporting wafer is subjected to annealing at 1100°

C. or higher in a reducing gas atmosphere containing hydrogen gas before said step of bonding.

12. A manufacturing method of an SOI wafer in accordance with claim 3, in which said supporting wafer is subjected to annealing at 1100°

C. or higher in a reducing gas atmosphere containing hydrogen gas before said step of bonding.

13. A manufacturing method of an SOI wafer in accordance with claim 4, in which said supporting wafer is subjected to annealing at 1100°

C. or higher in a reducing gas atmosphere containing hydrogen gas before said step of bonding.

14. A manufacturing method of an SOI wafer in accordance with claim 5, in which said supporting wafer is subjected to annealing at 1100°

C. or higher in a reducing gas atmosphere containing hydrogen gas before said step of bonding.

15. A manufacturing method of an SOI wafer in accordance with claim 6, in which said supporting wafer is subjected to annealing at 1100°

C. or higher in a reducing gas atmosphere containing hydrogen gas before said step of bonding.

16. A manufacturing method of an SOI wafer in accordance with claim 7, in which said supporting wafer is subjected to annealing at 1100°

C. or higher in a reducing gas atmosphere containing hydrogen gas before said step of bonding.

17. A manufacturing method of an SOI wafer in accordance with claim 8, in which said supporting wafer is subjected to annealing at 1100°

C. or higher in a reducing gas atmosphere containing hydrogen gas before said step of bonding.

10. An SOI wafer manufactured by a method comprising the steps of:

bonding a wafer for active layer with a supporting wafer via an insulating film interposed therebetween to thereby form a bonded wafer; and

then

reducing a film thickness in a part of said active layer wafer of said bonded wafer to thereby form an SOI layer for manufacturing said SOI wafer, wherein

said supporting wafer that has been bonded contains boron by an amount of 9×

10¹⁸ atoms/cm³ or more, and

said SOI layer has a thickness of 0.10 μ

m or thinner.