Method for processing a silicon wafer

Patent metadata

Field	Value
Publication number	US-9934988-B2
Application number	US-201615379243-A
Country	US
Kind code	B2
Filing date	Dec 14, 2016
Priority date	Dec 15, 2015
Publication date	Apr 3, 2018
Grant date	Apr 3, 2018

Abstract

Disclosed is a method for processing a semiconductor wafer. The method includes forming an oxygen containing region in the semiconductor wafer, wherein forming the oxygen containing region includes introducing oxygen via a first surface into the semiconductor wafer. The method further includes creating vacancies at least in the oxygen containing region and annealing at least the oxygen containing region in an annealing process so as to form oxygen precipitates.

First claim

What is claimed is:

1. A method, comprising:
forming an oxygen containing region in a semiconductor wafer, wherein forming the oxygen containing region comprises introducing oxygen via a first surface into the semiconductor wafer;
creating vacancies at least in the oxygen containing region, by implanting particles into the semiconductor wafer; and
annealing at least the oxygen containing region in an annealing process so as to form oxygen precipitates.

2. The method of claim 1 , wherein the semiconductor wafer is one of a CZ wafer, an MCZ wafer, and an FZ wafer.

3. The method of claim 1 , wherein forming the oxygen containing region further comprises:
diffusing the introduced oxygen in a further annealing process.

4. The method of claim 3 ,
wherein a temperature in the further annealing process is in a range between 1050° C. and 1300° C., and
wherein a duration of the further annealing process is in a range between 1 hour and 20 hours.

5. The method of claim 4 , wherein the temperature in the further annealing process is higher than 1100° C.

6. The method of claim 1 , wherein the oxygen-containing region is formed to extend between 0.1 and 20 micrometers from the first surface into the semiconductor wafer.

7. The method of claim 6 , wherein the oxygen containing region is formed to extend between 1 and 5 micrometers from the first surface into the semiconductor wafer.

8. The method of claim 1 , wherein the oxygen containing region is formed to have an oxygen concentration of at least 5E17 atoms/cm −3 .

9. The method of claim 1 , wherein introducing the oxygen comprises implanting oxygen ions via the first surface into the semiconductor wafer.

10. The method of claim 9 , wherein implanting the oxygen ions comprises a plasma doping implantation process.

11. The method of claim 10 ,
wherein an implantation energy for implanting the oxygen ions is in a range between 0.5 keV and 10 keV, and
wherein an implantation dose for implanting the oxygen ions is in a range between 1E14 cm −2 and 1E18 cm −3 .

12. The method of claim 1 , wherein the vacancies at least in the oxygen containing region have a vacancy concentration in a range between 1E17 cm −3 and 1E19 cm −3 .

13. The method of claim 1 , wherein implanting the particles comprises implanting the particles via the first surface or via a second surface opposite the first surface.

14. The method of claim 1 , wherein the particles comprise at least one of protons and helium ions.

15. The method of claim 14 ,
wherein an implantation energy for implanting the particles is in a range between 1 MeV and 5 MeV if the implanted particles are protons, or
wherein the implantation energy is in a range between 3 MeV and 10 MeV if the implanted particles are helium ions.

16. The method of claim 13 , wherein the particles are implanted at an implantation dose of between 5E13 cm −2 and 1E15 cm −2 .

17. The method of claim 2 , further comprising:
forming a coating layer on the first surface after introducing the oxygen and before the annealing process.

18. The method of claim 17 , wherein the coating layer is selected from the group consisting of:
an amorphous silicon layer;
a monocrystalline silicon layer;
an oxygen containing layer; and
a nitrogen containing layer.

19. The method of claim 1 ,
wherein a temperature of the annealing process is in a range between 750° C. and 1100° C., and
wherein a duration of the annealing process is in a range between 1.5 hours and 30 hours.

20. The method of claim 3 , wherein the further annealing process comprises:
heating at least the oxygen containing region to a temperature between 750° C. and 850° C. for a duration between 0.5 hours and 10 hours; and
heating at least the oxygen containing region to a temperature between 950° C. and 1100° C. for a duration between 1 hour and 20 hours.

21. The method of claim 1 , further comprising:
generating crystal damages in the oxygen containing region.

22. The method of claim 21 , wherein generating the crystal damages comprises implanting particles via the first surface into the semiconductor water before or after introducing the oxygen.

23. The method of claim 22 , wherein the particles are selected from the group consisting of:
oxygen atoms; and
silicon atoms.

24. The method of claim 22 , wherein the particles are implanted at an implantation energy in a range between 500 keV and 4 MeV and an implantation doses in a range between 1E10 cm −2 and 1E13 cm −2 .

25. The method of claim 20 , where channeling is employed during the implanting.

26. The method of claim 1 , wherein a diameter of the wafer is at least 12 inches.

27. The method of claim 1 , further comprising:
removing a section of the semiconductor body beginning at the first surface so as to at least partially remove the oxygen precipitates.

28. The method of claim 27 , wherein removing the section of the semiconductor body comprises an etching process.

29. A method, comprising:
forming an oxygen containing region in a semiconductor wafer, wherein forming the oxygen containing region comprises introducing oxygen via a first surface into the semiconductor wafer;
creating vacancies at least in the oxygen containing region;
annealing at least the oxygen containing region in an annealing process so as to form oxygen precipitates; and
generating crystal damages in the oxygen containing region, by implanting particles via the first surface into the semiconductor wafer before or after introducing the oxygen.

30. The method of claim 29 , wherein the particles are selected group consisting of oxygen atoms and silicon atoms.

31. The method of claim 29 , wherein the particles are implanted at an implantation energy in a range between 500 keV and 4 MeV and an implantation doses in a range between 1E10 cm −2 and 1E13 cm −2 .

32. A method, comprising:
forming an oxygen containing region in a semiconductor wafer, wherein forming the oxygen containing region comprises introducing oxygen via a first surface into the semiconductor wafer;
creating vacancies at least in the oxygen containing region;
annealing at least the oxygen containing region in an annealing process so as to form oxygen precipitates; and
removing a section of the semiconductor body beginning at the first surface so as to at least partially remove the oxygen precipitates.

33. The method of claim 32 , wherein removing the section of the semiconductor body comprises an etching process.

Assignees

• Infineon Technologies Ag

Inventors

• Schustereder Werner
• Oefner Helmut
• Schulze Hans-Joachim
• Walia Sandeep

Classifications

• H10P50/642

  Chemical etching · CPC title

• H10P32/1204

  from a plasma phase · CPC title

• H10P30/208

  of electrically inactive species · CPC title

• H10P30/204

  into Group IV semiconductors · CPC title

• H10P14/3458

  Monocrystalline · CPC title