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. In one embodiment, the transition metal oxide is molybdenum trioxide (MoO 3 ), the chalcogen source is sulfur, the non-gaseous chalcogen scavenger is nickel and the transition metal dichalcogenide is molybdenum disulfide (MoS 2 ). An arrangement for forming a transition metal dichalcogenide layer on a substrate is also provided.
1. An arrangement for forming a transition metal dichalcogenide layer on a substrate, the arrangement comprising:
a chamber for containing a transition metal oxide and a non-gaseous chalcogen scavenger, wherein the non-gaseous chalcogen scavenger is disposed in proximity to the transition metal oxide;
a heating zone at which a chalcogen source is placed;
a substrate holder adapted to have a substrate positioned downstream of the chamber so as to have the substrate disposed downstream of the transition metal oxide and the chalcogen source; and
an inert gas source adapted to provide an inert gas flow towards the substrate holder, wherein the heating zone is positioned to have the chalcogen source disposed in a path of the inert gas flow from the inert gas source towards the substrate holder;
wherein the chamber has a closed end and an opening opposite to the closed end, wherein the opening is adapted to have the non-gaseous chalcogen scavenger disposed at the opening and in the chamber and 10 cm or less away from the transition metal oxide, and wherein the closed end is configured as a physical barrier which is (i) disposed between the transition metal oxide and the chalcogen source, (ii) adapted to have the transition metal oxide disposed at the closed end of the chamber, (iii) adapted to prevent the inert gas flow from directly contacting the transition metal oxide and the non-gaseous chalcogen scavenger.
2. The arrangement of claim 1 , wherein the arrangement further comprises a respective heating element adapted to independently provide heat to the transition metal oxide and the chalcogen source for vaporizing the transition metal oxide and the chalcogen source.
3. The arrangement of claim 1 , wherein the closed end configured as the physical barrier is positioned away from the chalcogen source.
4. The arrangement of claim 1 , wherein the arrangement is disposed in an enclosure.
5. The arrangement 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.
6. The arrangement of claim 1 , wherein the chalcogen source comprises sulfur, selenium, tellurium, or a combination thereof.
7. The arrangement of claim 1 , wherein the non-gaseous chalcogen scavenger comprises or consists of nickel.
8. The arrangement of claim 1 , wherein the substrate comprises sapphire, silicon, silicon dioxide, gallium nitride, aluminium nitride, a metal, a ceramic, or a combination thereof.