Method and arrangement for forming a transition metal dichalcogenide layer
A method of forming a transition metal dichalcogenide layer on a substrate is provided. The method may include providing a transition metal oxide, a chalcogen source, a non-gaseous chalcogen scavenger, and a substrate, wherein the substrate is disposed downstream of the transition metal oxide and the chalcogen source, and wherein the non-gaseous chalcogen scavenger is disposed in proximity to the transition metal oxide; generating vapors of the transition metal oxide and vapors of the chalcogen source, wherein the non-gaseous chalcogen scavenger reacts preferentially with the vapors of the chalcogen source; disposing the vapors generated from the transition metal oxide and the chalcogen source on the substrate; and reacting the vapors of the transition metal oxide and the chalcogen source on the substrate to obtain the transition metal dichalcogenide layer on the substrate. An arrangement for forming a transition metal dichalcogenide layer on a substrate is also provided.
1 . A method of forming a transition metal dichalcogenide layer on a substrate, the method comprising:
disposing, in a chamber having a closed end and an opening opposite to the closed end, a transition metal oxide at the closed end, and a non-gaseous chalcogen scavenger at the opening and in proximity to the transition metal oxide, wherein the non-gaseous chalcogen scavenger is 10 cm or less away from the transition metal oxide;
placing a chalcogen source in a heating zone with the closed end as a physical barrier disposed between the transition metal oxide and the chalcogen source;
disposing the substrate downstream of the transition metal oxide and the chalcogen source;
generating vapors of the transition metal oxide and vapors of the chalcogen source, wherein the non-gaseous chalcogen scavenger reacts preferentially with the vapors of the chalcogen source;
directing an inert gas from an inert gas source (i) toward the heating zone with the chalcogen source in a path the inert gas flows and (ii) at the vapors generated from the transition metal oxide and the chalcogen source toward the substrate, with the inert gas prevented from directly contacting the transition metal oxide and the non-gaseous chalcogen scavenger by the closed end, so as to dispose the vapors generated from the transition metal oxide and the chalcogen source on the substrate; and
reacting the vapors of the transition metal oxide and the chalcogen source on the substrate to obtain the transition metal dichalcogenide layer on the substrate.
2 . The method of claim 1 , wherein disposing, in the chamber, the transition metal oxide and the non-gaseous chalcogen scavenger comprises disposing the non-gaseous chalcogen scavenger downstream of the transition metal oxide.
3 . The method of claim 1 , wherein generating vapors of the transition metal oxide and vapors of the chalcogen source comprises preventing vapors of the chalcogen source from reacting with the transition metal oxide.
4 . The method of claim 3 , wherein preventing vapors of the chalcogen source from reacting with the transition metal oxide comprises disposing the physical barrier between the transition metal oxide and the chalcogen source.
5 . The method of claim 1 , wherein generating vapors of the transition metal oxide and vapors of the chalcogen source comprises heating the transition metal oxide and the chalcogen source to their respective temperature for vaporization.
6 . The method of claim 5 , wherein heating the transition metal oxide for vaporizing the transition metal oxide is carried out at a temperature in the range of 650° C. to 950° C.
7 . The method of claim 5 , heating the transition metal oxide further comprises drying the transition metal oxide before vaporizing the transition metal oxide.
8 . The method of claim 7 , wherein drying the transition metal oxide is carried out at a temperature in the range of 200° C. to 300° C.
9 . The method of claim 5 , wherein heating the chalcogen source for vaporizing the chalcogen source is carried out at a temperature in the range of 100° C. to 300° C.
10 . The method of claim 1 , wherein the transition metal oxide is selected from the group consisting of molybdenum oxide, tungsten oxide, chromium oxide, tin oxide, titanium dioxide, hafnium oxide, zirconium oxide, and a combination thereof.
11 . The method of claim 1 , wherein the chalcogen source comprises sulfur, selenium, tellurium, or a combination thereof.
12 . The method of claim 1 , wherein the non-gaseous chalcogen scavenger comprises or consists of nickel.
13 . The method of claim 1 , wherein the substrate comprises sapphire, silicon, silicon dioxide, gallium nitride, aluminium nitride, a metal, a ceramic, or a combination thereof.
14 . The method of claim 1 , wherein the transition metal dichalcogenide layer comprises molybdenum sulfide.
15 . The method of claim 1 , wherein the method is carried out in an inert environment.