Methods of forming conformal transition metal dichalcogenide films for memory and logic applications

A method of forming a transition metal dichalcogenide film on a substrate surface comprising at least one feature, the method comprising:

• sequentially exposing the substrate surface to a metal precursor, purge gas, an oxidant, and the purge gas to directly deposit a transition metal oxide film, the metal precursor comprising bis(t-butylimino) bis(dimethylamino) tungsten or bis(t-butylimino) bis(dimethylamino) molybdenum, the transition metal oxide film being substantially conformal over the at least one feature;
• exposing the transition metal oxide film to a chalcogenide precursor to convert the transition metal oxide film to the transition metal dichalcogenide film, the chalcogenide precursor comprising H2S, wherein converting the transition metal oxide film is performed at a pressure of 1 Torr, the transition metal dichalcogenide film is a channel material in a 3D NAND device and has a thickness in a range of 20 Å to 30 Å, the substrate surface is maintained at a temperature in a range of about 350° C. to about 450° C., and the method is a thermal method that is performed without the use of plasma.