Methods to deposit and etch controlled thin layers of transition metal dichalcogenides
Transition metal dichalcogenides (TMDs) are deposited by atomic layer deposition as thin layers on a substrate. The TMDs may be grown on oxide substrates and may have a tunable TMD-oxide interface. The TMD may be etched using an atomic layer etching technique.
1. A method of etching a transition metal dichalcogenide coating comprising:
etching by a cycle of atomic layer etching comprising:
performing an atomic layer etching exposure of a transition metal halide precursor to the transition metal dichalcogenide coating at a first etching temperature between 50° C. and 400° C.;
performing an atomic layer etching exposure of water to the transition metal dichalcogenide coating at a second etching temperature between 50° C. and 400° C.; and
removing portions of the transition metal dichalcogenide coating.
2. The method of claim 1 , further comprising, prior to etching, depositing the transition metal dichalcogenide coating by:
performing an a atomic layer deposition cycle exposure for a deposition transition metal halide precursor at a first deposition temperature between 50° C. and 400° C.; and
performing a b atomic layer deposition cycle exposure for a sulfur precursor at a second deposition temperature between 50° C. and 400° C.,
wherein the etching transition metal halide precursor and the deposition transition metal halide precursor comprise the same halide.
3. The method of claim 2 , wherein the deposition metal transition is MoF 6 .
4. The method of claim 3 , wherein the sulfur precursor is H 2 S.
5. The method of claim 4 , wherein the transition metal dichalcogenide coating comprises MoS 2 .
6. The method of claim 1 , wherein the etching transition metal halide precursor comprises MoF 6 .
7. The method of claim 6 , wherein the atomic layer etching cycle exposure for the etching transition metal halide is for at least 15 seconds.
8. A method of etching a MoS 2 coating comprising:
etching by a cycle of atomic layer etching comprising:
performing an atomic layer etching exposure of a MoF 6 precursor to the MoS 2 coating at a first etching temperature between 50° C. and 400° C.;
performing an atomic layer etching exposure of water to the transition metal dichalcogenide coating at a second etching temperature between 50° C. and 400° C.; and
wherein the cycle of atomic layer etching removes portions of the MoS 2 coating, releasing volatile HF and MoF x O y products.