Method of producing thin layer of large area transition metal dichalcogenides MoS
An ultra-thin film transition metal dichalcogenide (“TMD”) supported on a support. The TMD is formed from a metal grown by atomic layer deposition (“ALD”) on a substrate. The metal is sulphurized to produce a TMD ultra-thin layer.
1. A method of preparing a substrate comprising:
depositing a seed layer on the substrate, the seed layer comprising AlMoF;
forming an ultra-thin transition metal layer by:
performing a atomic layer deposition cycles of transition metal precursor at a first deposition temperature between 100° C. and 300° C., and
performing b atomic layer deposition cycles of a second precursor at a second deposition temperature between 50° C. and 300° C., and
forming a transition metal dichalcogenide by sulphurization of the ultra-thin transition metal layer by exposure to a sulfur precursor.
2. The method of claim 1 , wherein sulphurization further comprises thermally annealing the ultra-thin transition metal layer at a sulphurization temperature.
3. The method of claim 1 , wherein the transition metal precursor for a atomic layer deposition is MoF 6 and, the precursor for b atomic layer deposition is Si 2 H 6 and the sulfur precursor is H 2 S further wherein the transition metal dichalcogenide is MoS 2 .
4. The method of claim 1 , wherein the a cycles each comprise: a 1 second dose followed by a gas purge.
5. The method of claim 2 , wherein the b cycle depositions each comprise: a 1 second dose followed by a 1 second gas purge.
6. The method of claim 2 , wherein the sulphurization temperature is greater than 300° C. and less than 600° C.
7. The method of claim 5 , wherein sulphurization further comprises exposing the transition metal layer to H 2 S.
8. The method of claim 5 , wherein the ultra-thin transition metal layer is deposited on a substrate before sulphurization.
9. The method of claim 1 , wherein the seed layer comprises a material different from the ultra-thin transition metal layer and the substrate and wherein the seed layer is lnm thick.
10. A method of preparing a substrate comprising:
depositing a seed layer on the substrate, the seed layer comprising AlMoF;
forming a transition metal layer of x atomic layers by repeating x times a atomic layer deposition process having the steps of:
performing a atomic layer deposition cycles of transition metal precursor at a first deposition temperature between 100° C. and 300° C., and
performing b atomic layer deposition cycles of a second precursor at a second deposition temperature between 50° C. and 300° C., and
converting the transition metal layer to dichalcogenide by sulphurization of the transition metal layer at a temperature of at least greater than or equal to 300° C. by exposure to at least one dose of a sulfur precursor,
wherein x is between 1 and 8.
11. The method of claim 10 , wherein the transition metal precursor is MoF 6 and Si 2 H 6 further, the transition metal dichalcogenide is MoS 2 , and the sulfur precursor is H 2 S.
12. The method of claim 10 , wherein the a cycles each comprise: a 1 second dose followed by a gas purge.
13. The method of claim 10 , wherein the b cycle depositions each comprise: a 1 second dose followed by a second gas purge.
14. The method of claim 10 , wherein the sulfur precursor comprises H 2 S.
15. The method of claim 10 , wherein the sulphurization temperature is between 300° C. and 600° C.
16. The method of claim 15 wherein the sulphurization is by 10 second doses of H 2 S exposure at a pressure of at least 1.5 Torr.