Thermally stable crystalline defect-free germanium bonded to silicon and silicon dioxide

• US 6,645,831 B1
• Filed: 05/07/2002
• Issued: 11/11/2003
• Est. Priority Date: 05/07/2002
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Jin, Beenyih, Chau, Robert S., Shaheen, Mohamad A.
• Primary Examiner(s): Thomas, Tom
• Assistant Examiner(s): MAGEE, THOMAS J
• Application Number:
  US10/141,596
• Publication Number:
  US 20030211704A1
• Time in Patent Office: 553 Days
• Field of Search: 438/455, 438/456, 438/457, 438/458, 438/459, 438/752, 257/506, 257/631
• US Class Current: 438/455
• CPC Class Codes: H01L 21/187 by direct bonding
• CPC Class Codes: H01L 21/28512 on semiconductor bodies comprising elements of Group IV of the Periodic Table
• CPC Class Codes: H01L 21/76256 using silicon etch back techniques, e.g. BESOI, ELTRAN
• CPC Class Codes: H01L 21/76275 Vertical isolation by bonding techniques
• CPC Class Codes: H01L 21/76283 Lateral isolation by refilling of trenches with dielectric material
• CPC Class Codes: H01L 29/165 in different semiconductor regions , e.g. heterojunctions
• CPC Class Codes: H01L 29/45 Ohmic electrodes

Abstract

A wafer pair comprising a substantially defect-free germanium wafer and methods of making the same. The wafer pair comprises the substantially defect-free germanium wafer directly bonded to a silicon wafer. The method of making the wafer pair comprises placing the silicon wafer in a wafer-bonding chamber, placing the germanium wafer on top or on bottom of the silicon wafer, and applying a local force to either the germanium wafer or to the silicon wafer to initiate bonding of the germanium wafer to the silicon wafer. The bonding occurs under a temperature ranging from about 23° C. to about 600° C. and under a vacuum condition inside a wafer-bonding chamber.

Claims

1. A method of forming a substantially defect-free germanium film on a semiconductor wafer comprising:

treating a semiconductor wafer to provide said semiconductor wafer with a first hydrophilic surface;

placing said semiconductor wafer in a wafer-bonding chamber;

treating a germanium wafer to provide said germanium wafer with a second hydrophilic surface;

placing said germanium wafer on top of or on bottom of said semiconductor wafer, said first hydrophilic surface facing said second hydrophilic surface; and

applying a local force to one of said germanium wafer and said semiconductor wafer to initiate bonding of said germanium wafer to said semiconductor wafer, said bonding forms a wafer pair.

2. A method as in claim 1 further comprising:

annealing said wafer pair after said germanium wafer is bonded to said semiconductor wafer.

3. A method as in claim 2 wherein an annealing temperature for said annealing ranges from 100°

C. to 600°

C.

4. A method as in claim 1 further comprising:

thinning said germanium wafer bonded to said semiconductor wafer to a desired thickness.

5. A method as in claim 1 wherein said semiconductor wafer is selected from a group consisting of a silicon wafer and a silicon wafer having a silicon oxide layer formed thereon.

6. A method as in claim 1 wherein said applying a local force to one of said germanium wafer and said semiconductor wafer comprises:

applying a force ranging from 3 Newton to 4000 Newton to a region near an edge of said one of said germanium wafer and said semiconductor wafer.

7. A method as in claim 1 further comprising:

obtaining a bonding condition for said wafer-bonding chamber.

8. A method as in claim 7 wherein said obtaining said bonding condition includes obtaining a bonding temperature and a bonding pressure.

9. A method as in claim 8 wherein said bonding temperature ranges from 22°

C. to 600°

C.

10. A method as in claim 8 wherein said bonding pressure is a sub-atmospheric pressure to place said wafer-bonding chamber under a vacuum condition.

16. A method as in claim 1 wherein said treating said germanium wafer to provide said germanium wafer with said second hydrophilic surface comprises treating said germanium wafer with a hydrofluoric solution.

17. A method as in claim 16 wherein said hydrofluoric solution is about less than 0.05% (v/v).

18. A method as in claim 1 further comprising:

annealing said wafer pair after said germanium wafer is bonded to said semiconductor wafer, said annealing includes ramping up temperature at a rate of about or less than 1°

C./min and ramping down temperature at a rate of about or less than 2°

C./min.

19. A method as in claim 18 wherein an annealing temperature for said annealing ranges from 100°

C. to 600°

C.

11. A method of forming a substantially defect-free germanium film on a semiconductor wafer comprising:

cleaning a silicon wafer to provide said silicon wafer with a first hydrophilic surface;

cleaning a germanium wafer to provide said germanium wafer with a second hydrophilic surface;

placing said silicon wafer in a wafer-bonding chamber;

placing said germanium wafer on top or on bottom of said silicon wafer, said first hydrophilic surface facing said second hydrophilic surface;

applying a local force to a region near an edge of one of said germanium wafer and said silicon wafer to initiate bonding of said germanium wafer to said silicon wafer, said bonding forming a wafer pair; and

annealing said wafer pair after said germanium wafer is bonded to said silicon wafer.

12. A method as in claim 11 further comprising:

thinning said germanium wafer bonded to said silicon wafer to a desired thickness.

13. A method as in claim 11 wherein an annealing temperature for said annealing ranges from 100°

C. to 600°

C., wherein a bonding temperature for said wafer-bonding chamber ranges from 22°

C. to 600°

C., and wherein a bonding pressure for said wafer-bonding chamber is less than 1 Torr.

14. A method as in claim 11 wherein said applying a local force to one of said germanium wafer and said silicon wafer comprises applying a force ranging from 3 Newton to 4000 Newton.

15. A method as in claim 11 wherein said silicon wafer having a silicon oxide layer formed thereon.

20. A method as in claim 11 further comprising:

annealing said wafer pair after said germanium wafer is bonded to said semiconductor wafer, said annealing includes ramping up temperature at a rate of about or less than 1°

C./min and ramping down temperature at a rate of about or less than 2°

C./min.

21. A method as in claim 20 wherein an annealing temperature for said annealing ranges from 100°

C. to 600°

C.

22. A method of forming a substantially defect-free germanium film on a semiconductor wafer comprising:

treating a semiconductor wafer to provide said semiconductor wafer with a first hydrophilic surface;

placing said semiconductor wafer in a wafer-bonding chamber;

treating a germanium wafer to provide said germanium wafer with a second hydrophilic surface;

placing said germanium wafer on top of or on bottom of said semiconductor wafer, said first hydrophilic surface facing said second hydrophilic surface;

introducing a moisture containing carrier gas into said wafer-bonding chamber; and

applying a local force to one of said germanium wafer and said semiconductor wafer to initiate bonding of said germanium wafer to said semiconductor wafer, said bonding forms a wafer pair.

23. A method as in claim 22 further comprising:

annealing said wafer pair after said germanium wafer is bonded to said semiconductor wafer, said annealing includes ramping up temperature at a rate of about or less than 1°

C./min and ramping down temperature at a rate of about or less than 2°

C./min.

24. A method as in claim 23 wherein said annealing further comprising:

ramping up temperature for said annealing at a rate of about 1°

C./min and maintaining said temperature at about 100°

C. for about 2 hours; and

ramping up said temperature from about 100°

C. to about 150°

C. at a rate of about 1°

C./min maintaining said temperature at about 150°

C. for about 6 hours.

25. A method as in claim 22 wherein an annealing temperature for said annealing ranges from 100°

C. to 600°

C.