Method for treating graphene sheets for large-scale transfer using free-float method

• US 10,017,852 B2
• Filed: 04/14/2016
• Issued: 07/10/2018
• Est. Priority Date: 04/14/2016
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Heise, Scott E., Bedworth, Peter V., Swett, Jacob L., Sinton, Steven W.
• Primary Examiner(s): OLSEN, ALLAN W
• Application Number:
  US15/099,464
• Publication Number:
  US 20170298504A1
• Time in Patent Office: 817 Days
• Field of Search: None
• CPC Class Codes: C01B 32/194 After-treatment
• CPC Class Codes: C23C 16/01 on temporary substrates, e.g. substrates subsequently removed by etching
• CPC Class Codes: C23C 16/26 Deposition of carbon only
• CPC Class Codes: C23C 16/56 After-treatment
• CPC Class Codes: C23F 1/18 for etching copper or alloys thereof

Abstract

A method for transferring a graphene sheet from a copper substrate to a functional substrate includes forming the graphene sheet on the copper substrate using chemical vapor deposition, and irradiating the graphene sheet disposed on the copper substrate with a plurality of xenon ions using broad beam irradiation to form a prepared graphene sheet. The prepared graphene sheet is resistant to forming unintentional defects induced during transfer of the prepared graphene sheet to the functional substrate. The method further includes removing the copper substrate from the prepared graphene sheet using an etchant bath, floating the prepared graphene sheet in a floating bath, submerging the functional substrate in the floating bath, and decreasing a fluid level of the floating bath to lower the prepared graphene sheet onto the functional substrate.

Claims

1. A method for transferring a graphene sheet from a copper substrate to a functional substrate comprising:

forming the graphene sheet on the copper substrate using chemical vapor deposition;

irradiating the graphene sheet formed on the copper substrate with a plurality of xenon ions using broad beam irradiation to form a prepared graphene sheet;

removing the copper substrate from the prepared graphene sheet using an etchant bath;

floating the prepared graphene sheet in a floating bath;

submerging the functional substrate in the floating bath; and

decreasing a fluid level of the floating bath to lower the prepared graphene sheet onto the functional substrate.

2. The method of claim 1, wherein the graphene sheet comprises an area of 1 cm² or larger.

3. The method of claim 1, wherein the broad beam irradiation is collimated.

4. The method of claim 1, wherein the plurality of xenon ions is applied at a voltage in a range of about 100 V to about 1500 V.

5. The method of claim 1, wherein the plurality of xenon ions is applied at a voltage in a range of about 250 V to about 750 V.

6. The method of claim 1, wherein the plurality of xenon ions is applied at a voltage of about 500 V.

7. The method of claim 1, further comprising heating the graphene sheet formed on the copper substrate to a temperature ranging from about 50°

C. to about 100°

C.

8. The method of claim 1, further comprising heating the graphene sheet disposed on the copper substrate to a temperature of about 80°

C.

9. The method of claim 1, wherein the plurality of xenon ions is provided at a flux of about 6.24×

10¹¹ Xe<sup>−

1</sup>/cm²/s to about 6.24×

10¹⁴ Xe⁺/cm²/s.

10. The method of claim 1, wherein the plurality of xenon ions is provided at a flux of about 6.24×

10¹² Xe⁺/cm²/s to about 6.24×

10¹³ Xe⁺/cm²/s.

11. The method of claim 1, wherein the plurality of xenon ions is provided at a flux of about 3.75×

10¹³ Xe⁺/cm²/s.

12. The method of claim 1, wherein the graphene sheet formed on the copper substrate is irradiated with the plurality of xenon ions for a contact time resulting in a total fluence of about 6.24×

10¹² Xe⁺/cm² to about 2.5×

10¹³ Xe⁺/cm².

13. The method of claim 1, wherein the graphene sheet formed on the copper substrate is irradiated with the plurality of xenon ions for a contact time resulting in a total fluence of about 1.25×

10¹³ Xe⁺/cm².

14. A method for transferring a graphene sheet from a copper substrate to a functional substrate comprising:

forming the graphene sheet on the copper substrate using chemical vapor deposition;

irradiating the graphene sheet formed on the copper substrate with a plurality of neon ions using broad beam irradiation to form a prepared graphene sheet;

removing the copper substrate from the prepared graphene sheet using an etchant bath;

floating the prepared graphene sheet in a floating bath;

submerging the functional substrate in the floating bath; and

decreasing a fluid level of the floating bath to lower the prepared graphene sheet onto the functional substrate.

15. The method of claim 14, further comprising heating the graphene sheet formed on the copper substrate to a temperature of about 50°

C. to about 100°

C.

16. The method of claim 14, wherein the graphene sheet formed on the copper substrate is irradiated with the plurality of neon ions for a contact time resulting in a total fluence of about 6.24×

10¹² ions/cm² to about 7.5×

10¹³ ions/cm².

17. The method of claim 14, wherein the graphene sheet formed on the copper substrate is irradiated with the plurality of neon ions for a contact time resulting in a total fluence of up to 2×

10¹⁴ ions/cm².

18. A method for transferring a graphene sheet from a growth substrate to a functional substrate comprising:

forming the graphene sheet on the growth substrate;

irradiating the graphene sheet formed on the growth substrate with a plurality of ions to form a prepared graphene sheet;

removing the growth substrate from the prepared graphene sheet using an etchant bath;

floating the prepared graphene sheet in a floating bath;

submerging the functional substrate in the floating bath; and

decreasing a fluid level of the floating bath to lower the prepared graphene sheet onto the functional substrate.

19. The method of claim 18, wherein the graphene sheet comprises an area of 1 cm² or larger.

20. The method of claim 18, wherein the growth substrate is a copper substrate.

21. The method of claim 18, wherein the growth substrate is a nickel substrate.

22. The method of claim 20, wherein the graphene sheet is formed on the copper substrate using chemical vapor deposition.

23. The method of claim 21, wherein the graphene sheet is formed on the nickel substrate using chemical vapor deposition.

24. The method of claim 18, wherein the plurality of ions comprises noble gas ions.

25. The method of claim 24, wherein the noble gas ions comprise xenon ions.

26. The method of claim 24, wherein the noble gas ions comprise neon ions.

27. The method of claim 24, wherein the noble gas ions comprise argon ions.

28. The method of claim 18, wherein the plurality of ions is applied to the graphene sheet formed on the growth substrate using broad beam irradiation.

29. The method of claim 28, wherein the broad beam irradiation is collimated.

30. The method of claim 18, wherein the plurality of ions is applied to the graphene sheet formed on the growth substrate at a voltage of about 100 V to about 1500 V.

31. The method of claim 18, wherein the plurality of ions is applied at a flux of about 1 nA/mm² to about 1000 nA/mm².

32. The method of claim 18, wherein the plurality of ions is applied at a flux of about 10 nA/mm² to about 100 nA/mm².

33. The method of claim 18, wherein the plurality of ions is applied at a flux of about 40 nA/mm² to about 80 nA/mm².

34. The method of claim 18, wherein the plurality of ions is applied at a flux of about 60 nAs/mm².

35. The method of claim 18, wherein the graphene sheet formed on the growth substrate is irradiated with the plurality of ions for a contact time resulting in a total fluence of about 10 nAs/mm² to about 120 nAs/mm².

36. The method of claim 18, wherein the graphene sheet formed on the growth substrate is irradiated with the plurality of ions for a contact time resulting in a total fluence of about 10 nAs/mm² to about 40 nAs/mm².

37. The method of claim 18, wherein the graphene sheet formed on the growth substrate is irradiated with the plurality of ions for a contact time resulting in a total fluence of about 20 nAs/mm².