Method for improved growth of two-dimensional transition metal dichalcogenides

Patent metadata

Field	Value
Publication number	US-9620665-B1
Application number	US-201615184008-A
Country	US
Kind code	B1
Filing date	Jun 16, 2016
Priority date	Jun 17, 2015
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

Processes for controlling the growth and thickness of two-dimensional transition metal dichalcogenides are provided. The process modifies an insulator substrate surface with an electron or ion beam to create charged areas on the substrate surface. The treated surface allows for hydroxylation of the charged species which serves as nucleation sites for the seed particles during chemical vapor deposition that promotes growth of thin layers of transition metal dichalcogenides.

First claim

What is claimed is:

1. A method for controlled growth of transition metal dichalcogenides (TMD) comprising
applying an electron or focused ion beam to an insulator surface to produce a charged area;
exposing the insulator surface to water molecules wherein the charged area comprises hydroxyl groups; and
depositing the TMD at a thickness of about 0.7 nm to 2.1 nm on said insulator surface using a chemical vapor deposition process.

2. The method of claim 1 , wherein the charged area has a defined pattern, shape or line.

3. The method of claim 1 , wherein the focused ion beam comprises gallium ions.

4. The method of claim 1 , wherein the insulator surface is comprised of a material selected from the group consisting of silicon oxides, Al 2 O 3 , h-BN and phylosilicates.

5. The method of claim 1 , wherein the insulator surface consist essentially of SiO 2 .

6. The method of claim 1 , wherein the TMD is MX 2 wherein M is a metal selected from the group consisting of Mo and W and wherein X is a nonmetal selected from the group consisting of S, Se and Te.

7. The method of claim 1 , wherein the TMD is MoS 2 .

8. The method of claim 1 , wherein the charged area further comprises seed particles.

9. The method of claim 8 , wherein the seed particles are at least one compound selected from the group consisting of MoO 3 , MoOS 2 , MoO 2 S, MoO 2 , MoOS or mixtures thereof.

10. The method of claim 1 , wherein the chemical vapor deposition process occurs inside a tube furnace.

11. A method for controlled growth of transition metal dichalcogenides (TMD) comprising
treating a substrate surface comprising SiO 2 with a focused ion beam to produce a charged area have a defined pattern, line or shape;
exposing the charged area to water molecules wherein the charged area comprises hydroxyl groups; and
depositing MoS 2 at a thickness of about 0.7 nm to 2.1 nm on the substrate surface by exposing said substrate surface to molybdenum trioxide and sulfur under an inert atmosphere.

Assignees

• Us Army

Inventors

• Bartolucci Stephen F
• Kaplan Daniel B

Classifications

• H10P14/3436 Primary

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

• H10P14/2921

  being crystalline insulating materials · CPC title

• H10P14/36

  characterised by treatments done before the formation of the materials · CPC title

• H10P14/24

  using chemical vapour deposition [CVD] · CPC title

• H01L31/18 Primary

  Electricity · mapped topic