Systems and methods for assembling two-dimensional materials

Patent metadata

Field	Value
Publication number	US-2016240692-A1
Application number	US-201615016933-A
Country	US
Kind code	A1
Filing date	Feb 5, 2016
Priority date	Aug 9, 2013
Publication date	Aug 18, 2016
Grant date	—

Abstract

Heterostructures can include multilevel stacks with an electrical contact on a one-dimensional edge of a two-dimensional active layer. A multilevel stack can be provided having a first two-dimensional layer encapsulated between a second layer and a third layer. A first edge of the first two-dimensional layer can be exposed by etching. A metal can be deposited on the edge of the first two-dimensional layer to form an electrical contact.

First claim

1 . A method for connecting an electrical contact to a two-dimensional layer along a one-dimensional edge thereof comprising:
providing a multilevel stack comprising a first two-dimensional layer encapsulated between a second layer and a third layer; exposing an edge of the first two-dimensional layer; and depositing a metal on the edge of the first two-dimensional layer.

2 . The method of claim 1 , wherein the first two-dimensional layer comprises graphene.

3 . The method of claim 1 , wherein the second layer and the third layer comprise hexagonal boron nitride.

4 . The method of claim 1 , wherein the providing comprises encapsulating the first two-dimensional layer between the second layer and the third layer.

5 . The method of claim 4 , wherein the encapsulating comprises:
disposing a material forming the second layer onto a polymer layer; stamping a material forming the first two-dimensional layer onto the material forming the second layer; and stamping a material forming the third layer onto the material forming the first two-dimensional layer.

6 . The method of claim 5 , wherein the disposing comprises exfoliating.

7 . The method of claim 5 , wherein the disposing comprises stamping.

8 . The method of claim 5 , wherein the polymer layer comprises a polymer thin film.

9 . The method of claim 5 , wherein stamping the material forming the first layer comprises:
disposing the material forming the first layer onto a substrate; and contacting the material forming the first layer with the material forming the second layer.

10 . The method of claim 9 , wherein the disposing the material forming the first layer onto a substrate comprises exfoliating a flake of the material forming the first layer onto the substrate.

11 . The method of claim 9 , wherein the disposing the material forming the first layer onto a substrate comprises chemical vapor deposition.

12 . The method of claim 5 , further comprising stamping alternating flakes of the material forming the first two-dimensional layer and flakes of the material forming the third layer to add additional layers to the multilevel stack.

13 . The method of claim 1 , wherein the exposing the edge of the first two-dimensional layer comprises etching.

14 . The method of claim 13 , wherein the etching comprises plasma-etching.

15 . The method of claim 13 , further comprising:
defining a mask on the second layer prior to etching; and etching regions of the multilevel stack outside of the mask.

16 . The method of claim 15 , wherein the defining the mask comprises electron-beam lithography of a resist.

17 . The method of claim 1 , wherein the depositing comprises electron-beam evaporation.

18 . The method of claim 1 , wherein the depositing comprises thermal evaporation.

19 . The method of claim 1 , wherein the metal comprises chromium.

20 . The method of claim 1 , wherein the metal comprises at least one metal selected from a group consisting of palladium, gold, titanium, nickel, aluminum, and niobium.

21 . The method of claim 1 , wherein the heterostructure comprising the deposited metal has a contact resistance of less than about 150 Ω·μm.

22 . The method of claim 1 , wherein the heterostructure comprising the deposited metal has a room-temperature mobility of at least about 140,000 cm 2 /Vs.

23 . The method of claim 1 , wherein the heterostructure comprising the deposited metal has a sheet resistivity of less than about 40 Ω/square at n>4×10 12 cm −2 .

24 . A heterostructure manufactured by a process comprising:
providing a multilevel stack comprising a first two-dimensional layer encapsulated between a second layer and a third layer; exposing an edge of the first two-dimensional layer; and depositing a metal on the edge of the first two-dimensional layer.

25 . The heterostructure of claim 24 , wherein the first two-dimensional layer comprises graphene.

26 . The heterostructure of claim 24 , wherein the second layer and the third layer comprise hexagonal boron nitride.

27 . The heterostructure of claim 24 , wherein the providing comprises encapsulating the first two-dimensional layer between the second layer and the third layer.

28 . The heterostructure of claim 27 , wherein the encapsulating comprises:
disposing a material forming the second layer onto a polymer layer; stamping a material forming the first two-dimensional layer onto the material forming the second layer; and stamping a material forming the third layer onto the material forming the first two-dimensional layer.

29 . The heterostructure of claim 28 , further comprising stamping alternating flakes of the material forming the first two-dimensional layer and flakes of the material forming the third layer to add additional layers to the multilevel stack.

30 . The heterostructure of claim 24 , wherein the exposing the edge of the first two-dimensional layer comprises etching.

31 . The heterostructure of claim 30 , wherein the etching comprises plasma-etching.

32 . The heterostructure of claim 30 , further comprising:
defining a mask on the second layer prior to etching; and etching regions of the multilevel stack outside of the mask.

33 . The heterostructure of claim 32 , wherein defining the mask comprises electron-beam lithography of a resist.

34 . The heterostructure of claim 24 , wherein the depositing comprises electron-beam evaporation.

35 . The heterostructure of claim 24 , wherein the metal comprises chromium.

36 . The heterostructure of claim 24 , wherein the heterostructure has a contact resistance of less than about 150 Ω·μm.

37 . The heterostructure of claim 24 , wherein the heterostructure has a room-temperature mobility of at least about 140,000 cm 2 /Vs.

38 . The heterostructure of claim 24 , wherein the heterostructure has a sheet resistivity of less than about 40 Ω/square at n>4×10 12 cm −2 .

39 . A heterostructure comprising:
a first two-dimensional layer comprising an electrical contact disposed on a one-dimensional edge thereof; a second layer; and a third layer,
wherein the first two-dimensional layer is disposed between the second layer and the third layer.

40 . The heterostructure of claim 39 , wherein the first two-dimensional layer comprises graphene.

41 . The heterostructure of claim 39 , wherein the second layer and the third layer comprise hexagonal boron nitride.

42 . The heterostructure of claim 39 , wherein the electrical contact comprises chromium.

43 . The heterostructure of claim 39 , wherein the heterostructure has a contact resistance of less than about 150 Ω·μm.

44 . The heterostructure of claim 39 , wherein the heterostructure has a room-temperature mobility of at least about 140,000 cm 2 /Vs.

45 . The heterostructure of claim 39 , wherein the heterostructure has a sheet resistivity of less than about 40 Ω/square at n>4×10 12 cm −2 .

Assignees

• Univ Columbia

Inventors

• Shepard Kenneth L
• Meric Inanc
• Dean Cory R
• Wang Lei
• Hone James

Classifications

• H10P50/691

  for Group V materials or Group III-V materials · CPC title

• H10P50/242

  of Group IV materials · CPC title

• H10P14/3466

  Crystal orientation · CPC title

• H10P14/3416

  Nitrides · CPC title

• H10P14/3406

  Carbon, e.g. diamond-like carbon · CPC title