Method for Manufacturing Direct Bonded SOI Wafer and Direct Bonded SOI Wafer Manufactured by the Method

• US 20070148912A1
• Filed: 12/21/2006
• Published: 06/28/2007
• Est. Priority Date: 12/22/2005
• Status: Active Grant

• Current Assignee: Sumco Corporation
• Original Assignee: Sumco Corporation
• Inventors: Ono, Isoroku, Morita, Etsurou, Okawa, Shinji
• Granted Patent: US 7,781,309 B2
• Time in Patent Office: Days
• US Class Current: 438/455
• CPC Class Codes: H01L 21/2007 Bonding of semiconductor wafers to insulating substrates or to semiconducting substrates using an intermediate insulating layer H01L21/2011 takes precedence; bonding of semiconductor wafers to semiconductor wafers for junction formation H01L21/187
• CPC Class Codes: H01L 21/76251 using bonding techniques
• CPC Class Codes: H01L 21/76254 with separation/delamination along an ion implanted layer, e.g. Smart-cut, Unibond

Abstract

There are provided a method for manufacturing a direct bonded SOI wafer in which the entire buried oxide film layer is covered and not exposed and a direct bonded SOI wafer. This is the improvement of a method for manufacturing a direct bonded SOI wafer comprising the process of (A) forming a laminated body by laminating a semiconductor wafer and a support wafer via an oxide film; and (B) forming a thin-film single crystal silicon layer on the support wafer using a buried oxide film layer by film-thinning the semiconductor wafer to a predetermined thickness, wherein in a process (C) the entire buried oxide film layer is covered by a main surface on the laminating side of the support wafer and the single crystal silicon layer. The covering of the entire buried oxide film layer is carried out by, between process (A) and (B), removing the oxide film formed on the circumferential end edge of the main surface on the laminating side and the chamfered portion to leave the oxide film only on the laminated surface except the circumferential end edge.

Claims

1. A method for manufacturing a direct bonded SOI wafer comprising the step of (A) forming a laminated body having first and second main surfaces by laminating a semiconductor wafer on a laminating side of a support wafer via an oxide film;

and the step of (B) forming a thin-film single crystal silicon layer on said support wafer via a buried oxide film layer by thinning said semiconductor wafer wherein

in a step (C), the entire buried oxide film layer is covered by a main surface on the laminating side of said support wafer and said single crystal silicon layer.

2. The method for manufacturing the direct bonded SOI wafer according to claim 1, wherein the covering of the entire buried oxide film layer in step (C) is carried out by:

forming the oxide film in step (A) on a main surface on either of the laminating side of said semiconductor wafer, said support wafer or both and on a chamfered portion continuing to the first main surface, or on both the first and second main surfaces of said semiconductor wafer, said support wafer, a chamfered portion continuing to both the main surfaces or all three, and between steps (A) and (B), removing the oxide film formed on the circumferential end edge of the main surface on said laminating side and the chamfered portion to leave the oxide film only on the laminating surface and not on the circumferential end edge.

3. The method for manufacturing the direct bonded SOI wafer of claim 1, wherein the film-thinning of the semiconductor wafer in step (B) is carried out by mechanical processing, chemical etching or gas-phase etching of said semiconductor wafer.

4. The method for manufacturing the direct bonded SOI wafer of claim 3, wherein the film-thinning of the semiconductor wafer in step (B) is carried out by mechanical processing comprising grinding and polishing the side opposite to the laminating side of said semiconductor wafer after the laminating step.

5. The method for manufacturing the direct bonded SOI wafer of claim 3, wherein the film-thinning of the semiconductor wafer in step (B) is carried out by mechanical processing comprising cutting said semiconductor wafer parallel to the main surface after the laminating step.

6. The method for manufacturing the direct bonded SOI wafer of claim 1, wherein the film-thinning of the semiconductor wafer in step (B) is carried out by implanting ions on the main surface on the laminating side of the semiconductor wafer and on a chamfered portion continuing to the first main surface to form an ion implanted area inside the semiconductor wafer and by separating and removing said semiconductor wafer from the thin-film layer in the ion implanted area by applying a heat treatment to the laminated body after the laminating step.

7. The method for manufacturing the direct bonded SOI wafer of claim 1, wherein the film-thinning of the semiconductor wafer in step (B) is carried out by producing a poromeric porous silicon layer by anodization on the main surface on the laminating side of the semiconductor wafer and on a chamfered portion continuing to the main surface, by forming a single crystal silicon thin-film layer on said porous silicon layer by epitaxial growth after a hydrogen annealing treatment on said porous silicon layer in this order, forming the oxide film on the main surface on either of the laminating side of said single crystal silicon thin-film layer, the support wafer or both and on a chamfered portion continuing to the main surface, and separating and removing said semiconductor wafer from said single crystal silicon thin-film layer in said porous silicon layer by applying a heat treatment to the laminated body after laminating.

8. The method for manufacturing the direct bonded SOI wafer of claim 2, wherein the removal of the oxide film between process (A) and process (B) is carried out by polishing.

9. The method for manufacturing the direct bonded SOI wafer of claim 2, wherein the removal of the oxide film between process (A) and process (B) is carried out by chemical etching.

10. The method for manufacturing the direct bonded SOI wafer of claim 9, wherein the chemical etching is carried out with an HF solution with the weight ratio of HF:

H₂O within a range of 1;

0 to 10.

11. The method for manufacturing the direct bonded SOI wafer of claim 1, wherein the main surface of the laminating side of the semiconductor wafer, the support wafer or both in step (A) is laminated after washing with an SC-1 solution under an oxidized atmosphere.

12. The method for manufacturing the direct bonded SOI wafer of claim 1, wherein the main surface of the laminating side of the semiconductor wafer, the support wafer or both in step (A) is laminated after washing with a solution containing an organic acid and ozone under an oxidized atmosphere.

13. The method for manufacturing the direct bonded SOI wafer of claim 1, wherein the main surface of the laminating side of the semiconductor wafer, the support wafer or both in step (A) is laminated after washing with a diluted HF solution wherein the weight ratio of HF:

H₂O is within a range of 1;

50 to 400.

14. A direct bonded SOI wafer manufactured by the method of claim 1.

15. A direct bonded SOI wafer manufactured by the method of claim 2.

16. A direct bonded SOI wafer manufactured by the method of claim 3.

17. A direct bonded SOI wafer manufactured by the method of claim 4.

18. A direct bonded SOI wafer manufactured by the method of claim 5.

19. A direct bonded SOI wafer manufactured by the method of claim 6.

20. A direct bonded SOI wafer manufactured by the method of claim 7.

21. A direct bonded SOI wafer manufactured by the method of claim 8.

22. A direct bonded SOI wafer manufactured by the method of claim 9.

23. A direct bonded SOI wafer manufactured by the method of claim 10.

24. A direct bonded SOI wafer manufactured by the method of claim 11.

25. A direct bonded SOI wafer manufactured by the method of claim 12.

26. A direct bonded SOI wafer manufactured by the method of claim 13.