Laser-assisted atomic layer deposition of 2D metal chalcogenide films

Patent metadata

Field	Value
Publication number	US-2017073812-A1
Application number	US-201615257493-A
Country	US
Kind code	A1
Filing date	Sep 6, 2016
Priority date	Sep 15, 2015
Publication date	Mar 16, 2017
Grant date	—

Abstract

Methods of forming 2D metal chalcogenide films using laser-assisted atomic layer deposition are disclosed. A direct-growth method includes: adhering a layer of metal-bearing molecules to the surface of a heated substrate; then reacting the layer of metal-bearing molecules with a chalcogenide-bearing radicalized precursor gas delivered using a plasma to form an amorphous 2D film of the metal chalcogenide; then laser annealing the amorphous 2D film to form a crystalline 2D film of the metal chalcogenide, which can have the form MX or MX 2 , where M is a metal and X is the chalcogenide. An indirect growth method that includes forming an MO 3 film is also disclosed.

First claim

What is claimed is:

1 . A method of forming a substantially two-dimensional (2D) film of a metal chalcogenide on a surface of a substrate, the method comprising:
a) adhering a layer of metal-bearing molecules to the surface of a heated substrate using an atomic layer deposition (ALD) process; b) reacting the layer of metal-bearing molecules with a chalcogenide-bearing radicalized precursor gas delivered using a plasma to form an amorphous and substantially 2D film of the metal chalcogenide; and c) laser annealing the amorphous and substantially 2D film to form therefrom a substantially crystalline and substantially 2D film of the metal chalcogenide, wherein the metal chalcogenide can have the form MX or MX 2 , where M is a metal and X is a chalcogenide.

2 . The method according to claim 1 , wherein the metal M is one of Mo and W and wherein the chalcogenide X is one of S, Se and Te.

3 . The method according to claim 1 , wherein the plasma includes X-bearing radicals.

4 . The method according to claim 3 , wherein the X-bearing radicals include H 2 S*.

5 . The method according to claim 1 , further comprising processing the substrate to remove the substantially crystalline and substantially 2D film from the surface of the substrate.

6 . The method according to claim 1 , wherein the substantially crystalline and substantially 2D film of the metal chalcogenide has dimensions of 25 mm×25 mm or greater.

7 . The method according to claim 1 , wherein acts a) and b) are repeated multiple times before performing act c).

8 . A method of forming a substantially two-dimensional (2D) film of a metal chalcogenide on a surface of a substrate, the method comprising:
a) adhering a layer of metal-bearing molecules to the surface of a heated substrate using an atomic layer deposition (ALD) process; b) causing an oxidant precursor gas to react with the layer of metal-bearing molecules to form a layer of MO 3 ; c) repeating acts a) and b) to form an MO 3 film having multiple layers of MO 3 ; d) causing a chalcogenide-bearing radicalized precursor gas to react with the MO 3 film to form an amorphous and substantially 2D film of the metal chalcogenide; and e) laser annealing the amorphous and substantially 2D film to form therefrom a substantially crystalline and substantially 2D film of the metal chalcogenide, wherein the metal chalcogenide can have the form MX or MX 2 , where M is a metal and X is a chalcogenide.

9 . The method according to claim 8 , wherein the metal M is one of Mo and W and wherein the chalcogenide X is one of S, Se and Te.

10 . The method according to claim 8 , wherein act d) includes providing the chalcogenide-bearing radicalized precursor gas using a plasma.

11 . The method according to claim 10 , wherein the chalcogenide-bearing radicalized precursor gas comprises H 2 S*.

12 . The method according to claim 8 , further comprising processing the substrate to remove the substantially crystalline and substantially 2D film from the surface of the substrate.

13 . The method according to claim 8 , wherein the substantially crystalline and substantially 2D film of the metal chalcogenide has dimensions of 25 mm×25 mm or greater.

14 . A method of forming a substantially two-dimensional (2D) film of a metal chalcogenide on a surface of a substrate, the method comprising:
a) adhering a layer of metal-bearing molecules to the surface of a heated substrate using an atomic layer deposition (ALD) process; b) causing an oxidant precursor gas to react with the layer of metal-bearing molecules to form a layer of MO 3 ; c) repeating acts a) and b) to form an MO 3 film having multiple layers of MO 3 ; d) laser annealing the MO 3 film to form therefrom an MO 2 film; e) causing a chalcogenide-bearing radicalized precursor gas to react with the MO 2 film to form an amorphous and substantially 2D film of the metal chalcogenide; and f) laser annealing the amorphous and substantially 2D film to form therefrom a substantially crystalline and substantially 2D film of the metal chalcogenide, wherein the metal chalcogenide can have the form MX or MX 2 , where M is a metal and X is a chalcogenide.

15 . The method according to claim 14 , wherein the metal M is one of Mo and W and wherein the chalcogenide X is one of S, Se and Te.

16 . The method according to claim 14 , wherein act e) includes providing the chalcogenide-bearing radicalized precursor gas using a plasma.

17 . The method according to claim 16 , wherein the chalcogenide-bearing radicalized precursor gas comprises H 2 S*.

18 . The method according to claim 14 , further comprising processing the substrate to remove the substantially crystalline and substantially 2D film from the surface of the substrate.

19 . The method according to claim 14 , wherein the substantially crystalline and substantially 2D film of the metal chalcogenide has dimensions of 25 mm×25 mm or greater.

20 . A method of forming a substantially two-dimensional (2D) film of a metal monochalcogenide (MX) or a metal dichalcogenide (MX 2 ) on a surface of a substrate using an atomic layer deposition process, the method comprising:
a) providing the substrate in a chamber interior having a pressure in the range from 0.1 Torr to 0.5 Torr and heating the substrate to a temperature of between 150° C. and 500° C.; b) introducing a metal-bearing precursor gas having a metal M to the chamber interior, wherein the metal-bearing precursor gas reacts with and remains on the substrate; c) purging the chamber interior of excess metal-bearing precursor gas; d) introducing a chalcogenide precursor gas into the chamber interior using a plasma, wherein the chalcogenide precursor gas reacts with the metal-bearing precursor gas that remains on the substrate, to produce an amorphous film of MX or MX 2 ; e) purging the chamber interior; and f) scanning a laser beam over the amorphous film to heat the amorphous film to a temperature of between 650° C. and 1200° C. to produce the substantially 2D film of either MX or MX 2 on the surface of the substrate, wherein the substantially 2D film is substantially crystalline.

21 . The method according to claim 20 , wherein the metal M is one of Mo and W.

22 . The method according to claim 20 , wherein the chalcogenide X is one of S, Se and Te.

23 . The method according to claim 20 , wherein the plasma includes X-bearing radicals.

24 . The method according to claim 23 , wherein the X-bearing radicals include H 2 S*.

25 . The method according to claim 20 , further comprising processing the substrate to remove the substantially crystalline and substantially 2D film from the surface of the substrate.

26 . The method according to claim 20 , wherein the laser beam has a nominal wavelength of 532 nm.

27 . The method according to claim 20 , wherein in act d), the providing of the chalcogenide precursor gas is performed in a continuous manner or a pulsed manner.

28 . The method according to claim 20 , wherein the 2D film has dimensions of 25 mm×25 mm or greater.

29 . The method according to claim 20 , wherein in act f), the laser scanning is performed in a raster scan.

30 . The method according to claim 20 , wherein the substrate is made of silicon or sapphire.

31 . The method according to claim 20 , wherei

Assignees

• Ultratech Inc

Inventors

• Sundaram Ganesh

Classifications

• H10P14/24

  using chemical vapour deposition [CVD] · CPC title

• H10P14/3436

  being chalcogenide semiconductor materials not being oxides, e.g. ternary compounds · CPC title

• H10P14/2905

  Silicon, silicon germanium or germanium · CPC title

• H10P14/2921

  being crystalline insulating materials · CPC title

• C23C16/56 Primary

  After-treatment · CPC title