THIN FILM SEMICONDUCTOR MATERIAL PRODUCED THROUGH REACTIVE SPUTTERING OF ZINC TARGET USING NITROGEN GASES

• US 20080264777A1
• Filed: 07/26/2007
• Published: 10/30/2008
• Est. Priority Date: 04/27/2007
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: YE, YAN
• Granted Patent: US 7,927,713 B2
• Time in Patent Office: Days
• US Class Current: 204/192.25
• CPC Class Codes: C23C 14/0036 Reactive sputtering
• CPC Class Codes: C23C 14/0676 Oxynitrides
• CPC Class Codes: H01L 21/02521 Materials
• CPC Class Codes: H01L 21/02554 Oxides
• CPC Class Codes: H01L 21/0257 Doping during depositing
• CPC Class Codes: H01L 21/02631 Physical deposition at reduced pressure, e.g. MBE, sputtering, evaporation
• CPC Class Codes: H01L 27/016 Thin-film circuits
• CPC Class Codes: H01L 29/22 including, apart from doping materials or other impurities, only AIIBVI compounds
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• CPC Class Codes: Y10T 428/12528 Semiconductor component

Abstract

The present invention generally comprises a semiconductor film and the reactive sputtering process used to deposit the semiconductor film. The sputtering target may comprise pure zinc (i.e., 99.995 atomic percent or greater), which may be doped with aluminum (about 1 atomic percent to about 20 atomic percent) or other doping metals. The zinc target may be reactively sputtered by introducing nitrogen and oxygen to the chamber. The amount of nitrogen may be significantly greater than the amount of oxygen and argon gas. The amount of oxygen may be based upon a turning point of the film structure, the film transmittance, a DC voltage change, or the film conductivity based upon measurements obtained from deposition without the nitrogen containing gas. The reactive sputtering may occur at temperatures from about room temperature up to several hundred degrees Celsius. After deposition, the semiconductor film may be annealed to further improve the film mobility.

Claims

1. A sputtering method, comprising:

disposing a zinc target in a sputtering chamber;

flowing a sputtering gas into the chamber, the sputtering gas comprising an oxygen containing gas and a nitrogen containing gas;

applying a bias to the target; and

depositing a semiconductor layer on a substrate, the semiconductor layer comprising the zinc, oxygen, and nitrogen.

2. The method of claim 1, wherein the oxygen containing gas and the nitrogen containing gas are flowed into the chamber at a flow ratio of nitrogen containing gas to oxygen containing gas in a range of about 10:

1 to about 100;

1.

3. The method of claim 2, wherein the ratio is about 20:

1.

4. The method of claim 1, further comprising annealing the deposited semiconductor layer.

5. The method of claim 4, wherein the zinc is doped with aluminum.

6. The method of claim 1, wherein the oxygen containing gas is oxygen.

7. The method of claim 6, wherein the nitrogen containing gas is nitrogen.

8. The method of claim 1, wherein the substrate has a surface area greater than about 0.04 square meters.

9. The method of claim 1, wherein the depositing occurs within a temperature range of about 25 degrees Celsius to about 50 degrees Celsius.

10. A sputtering method, comprising:

flowing a nitrogen containing gas and an oxygen containing gas into a sputtering chamber, the chamber having a metal target comprising zinc; and

sputter depositing a semiconductor layer onto the substrate, the semiconductor layer comprising zinc, oxygen, and nitrogen.

11. A semiconductor film, comprising zinc, oxygen, and nitrogen.

12. The semiconductor film of claim 11, wherein the film comprises a sheet resistance of between about 100 ohm/sq to about 1×

10⁷ ohm/sq.

13. The semiconductor film of claim 11, wherein the film comprises a resistivity of between about 0.001 to about 30 ohm-cm.

14. The semiconductor film of claim 11, wherein the film comprises a mobility of greater than about 30 cm²/V-s.

15. The semiconductor film of claim 14, wherein the film comprises a mobility of greater than about 90 cm²/V-s.

16. The semiconductor film of claim 11, wherein the film comprises a transmittance of up to about 80 percent.

17. The semiconductor film of claim 11, wherein the film comprises a graded band gap energy between about 3.1 eV and about 1.2 eV.

18. The semiconductor film of claim 11, wherein the film comprises a nitride peak and a nitrite peak as measured by XPS.

19. The semiconductor film of claim 11, wherein the film comprises a nitrite peak having a binding energy of about 403 eV in XPS and a concentration of about 2.7 atomic percent to about 5.6 atomic percent.

20. The semiconductor film of claim 19, wherein the film comprises a nitride peak having a binding energy of about 395 eV in XPS and a concentration of about 4.0 atomic percent to about 6.6 atomic percent.

21. A semiconductor film comprising zinc and having a mobility of greater than about 5 cm²/V-s.

22. The semiconductor film of claim 21, further comprising oxygen and nitrogen.

23. The semiconductor film of claim 21, further comprising Zn₃N₂ crystal with crystallographic orientations of (222) and (411).

24. The semiconductor film of claim 21, wherein the film is amorphous and has no clear peaks in an XRD measurement.

25. The semiconductor film of claim 21, wherein the film comprises a band gap energy below about 3.0 eV.

26. The semiconductor film of claim 21, wherein the film comprises a nitride peak and a nitrite peak as measured by XPS.

27. The semiconductor film of claim 21, wherein the film comprises a nitrite concentration of about 2.7 atomic percent to about 5.6 atomic percent.

28. The semiconductor film of claim 27, wherein the film comprises a nitride concentration of about 4.0 atomic percent to about 6.6 atomic percent.

37. The semiconductor film of claim 26, wherein the film comprises a nitride concentration of about 4.0 atomic percent to about 6.6 atomic percent.

29. A semiconductor film, when measured using x-ray diffraction, having a first peak of Zn₃N₂ and a second peak of Zn₃N₂.

30. The semiconductor film of claim 29, wherein the first peak comprises a Zn₃N₂ crystal with a crystallographic orientation of (222).

31. The semiconductor film of claim 29, wherein the second peak comprises a Zn₃N₂ crystal with a crystallographic orientation of (411).

32. The semiconductor film of claim 29, wherein a ratio of the first peak to the second peak is about 1.11:

1.

33. The semiconductor film of claim 29, wherein the first peak lies between about 31 and about 33.

34. The semiconductor film of claim 29, wherein the second peak lies between about 35 and about 42.5.

35. The semiconductor film of claim 29, wherein the film comprises a band gap energy below about 3.0 eV.

36. The semiconductor film of claim 29, wherein the film comprises a nitrite concentration of about 2.7 atomic percent to about 5.6 atomic percent.